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Objective: To evaluate the effects of uncoupling protein (UCP) 1, UCP2 and UCP3 gene variants on body composition and metabolic changes in response to chronic overfeeding and the recovery after the period of overfeeding. Subjects and design: Twenty-four normal weight men (21±2 y), who constituted 12 pairs of identical twins, ate a 4.2 MJ/day energy surplus, 6 days a week, during a period of 100 days. The subjects were asked to return to the laboratory for testing at 4 months and for a final examination 5 y after completion of the overfeeding protocol. Methods: Resting metabolic rate (RMR) measurements were performed before and after overfeeding. A 4.2 MJ test meal was consumed, after which calorimetric measurements were continued for 240 min. Total body fat was assessed by hydrodensitometry and total subcutaneous fat by the sum of eight skinfolds. Polymorphisms were typed by PCR and PCR-RFLP-techniques. Thyroid stimulating hormone (TSH) concentrations after a thyrotropin releasing hormone (TRH) injection were measured by radioimmunoassay (RIA). Results: The changes in body weight and adiposity were not different between UCP1 Bcl I, UCP2 alanine to valine (A55V), UCP2 insertion/deletion (I/D) or UCP3 Rsa I genotypes. However, the recovery from overfeeding was worse among G-allele carriers of the UCP1 Bcl I, I allele non-carriers of the UCP2 I/D, AV heterozygote subjects of the UCP2 A55V and CC subjects of the UCP3 Rsa I polymorphisms. RMR was lower both before (P=0.01) and after (P=0.001) overfeeding in subjects with the CC genotype of the UCP3 Rsa I polymorphism. Moreover, after overfeeding, the UCP2 A55V heterozygote and UCP3 Rsa I CC homozygote subjects had significantly higher respiratory quotient (RQ) values at rest (P

Summary Objective The aim of the present study was to assess the interaction of major dietary patterns with Cocaine- and Amphetamine-Regulated Transcript (CART) prepropeptide gene rs2239670 variant in apparently healthy obese Iranians. Methods A total of 288 apparently healthy obese participants aged 20-50 years were recruited in this cross-sectional study. Usual dietary intake was assessed using a 147-item semi-quantitative validated food frequency questionnaire. Genotyping of the CART gene rs2239670 polymorphism was conducted by the polymerase chain reaction-restriction fragment length polymorphism (PCR–RFLP). Results The results showed that the majority of the participants had GG genotype (65.4%). Three dietary patterns were extracted: prudent dietary pattern (PDP), legume dietary pattern (LDP), and mixed dietary pattern (MDP). There were significant interactions between PDP and rs2239670 variant on fat free mass (FFM) (p Interaction = 0.039), basal metabolic rate (BMR) (p Interaction = 0.039). Also, significant interactions were observed between LDP and rs2239670 polymorphism on the diastolic blood pressure (DBP) (p Interaction = 0.026), waist to hip ratio (WHR) (p Interaction = 0.050), agouti-related protein (AgRP) (p Interaction = 0.012), and α-melanocyte stimulating hormone (α-MSH) (p Interaction =0.006). Conclusions The CART rs2239670 SNP interacts with dietary patterns to affect some of the cardio-metabolic risk factors.

Aim: To highlight energy availability status, resting metabolic rate measures, dietary protein intake, and testosterone concentration in 4 elite male track cycling athletes (mean [SD]: age: 20.8 [1.5] y, body mass: 76.3 [3.6] kg, height: 181.8 [2.9] cm). Method: A cross-sectional observation included measures of energy availability (energy intake minus exercise energy expenditure, divided by fat-free mass), resting metabolic rate from indirect calorimetry, dietary protein intake from food records, blood analysis to assess sex hormone status, and performance markers. Results: Midrange testosterone (16.9–19.8 nmol/L), lowered resting metabolic rate ratio (0.76–0.98), varied luteinizing hormone (4–10 U/L), and suboptimal energy availability (26–41 kcal/kg fat-free mass/d, range) were observed in the male track cyclists. Protein intakes ranged from 2.0 g to 2.8 g protein/kg/d. Conclusion: The current cohort may have within-day energy deficiency, putting them in a catabolic state.

During aging total energy expenditure (TEE) decreases by 6 % per decade in women, parallel to the reduction in physical activity. Resting metabolic rate (RMR) decreases 1–2 % per decade and increases from 50 years (3 % per decade). There is a change in body composition not associated with the reduction in RMR or loss of fat-free mass (FFM). This change in body composition produces an increase in fat mass, and it is higher in women than in men. The change in body composition does not always imply a change in body weight (or body mass index). As the caloric intake requirements decrease with aging, the right quality of food and adequate portions become more important. Energy imbalances complicate health and quality of life in both malnutrition and overweight. The 7th edition of the Dietary Guidelines for the USA published in 2010 and incorporating MyPlate in 2011 are available resources to advise people and help improve nutrition, serving as a guide for adults and older active women also. Adequate calorie intakes should be matched to physical activity level in each, providing the required amount of macronutrients, vitamins, and minerals, and possible food supplements for active women to achieve proper weight control, energy balance, and heath.

Women energy requirements need be balance with total daily energy expenditure (TDEE). Hence, meeting of energy needs for all components of TDEE must be the most important concern for active females. Resting metabolic rate (RMR), thermic effect of food (TEF), and physical activity energy expenditure (PAEE) are the most important components of TDEE; where the most variable is the PAEE. The quantification of each component implies time consuming and expensive techniques, which are unviable in field and clinical settings. However, indirect methods have been developed to allow coaches, physicians, and nutritionists estimate TDEE. In this chapter, we cover the physiological relevance of RMR, TEF, and PAEE, and the indirect ways to obtain estimations of their values. On the other hand, other variables factors affecting TDEE as adaptive thermogenesis and non-exercise activity thermogenesis (NEAT) are highlighted. Finally, a case study is suggested in order to introduce basic metabolic calculations and physical activity level (PAL) concept.

Background & aims: \ud Obesity prevalence in people with phenylketonuria (PKU) is comparable to that of the general population but the underlying aetiology remains unknown. To assess body composition, dietary intake, moderate physical activity duration (MPAD) and energy expenditure (MPAEE), resting metabolic rate (RMR), diet-induced thermogenesis (DIT), fasting and postprandial fat (FOx) and carbohydrate oxidation (CHOOx), in PKU people and healthy Controls.\ud \ud Methods: \ud Participants were PKU people (n = 16) and healthy controls (n = 15). Body composition was measured with stable isotopes using deuterium as tracer, dietary intake from 4-day food diaries, MPAD and MPAEE from 7-day activity counts measured by triaxial accelerometers, calibrated against individual rates of oxygen consumption and carbon dioxide production, RMR, DIT, FOx and CHOOx by indirect calorimetry.\ud \ud Results: \ud Body composition, DIT, FOx, CHOOx and RMR did not differ between the PKU and the Control groups. MPAD (PKU, 73 ± 26 min/week; Control, 152 ± 43 min/week) and MPAEE (PKU, 404 ± 127 kcal/week; Control, 741 ± 153 kcal/week) were lower (P < 0.05) in the PKU than the Control group. Raised phenylalanine levels were inversely related with MPAD and MPAEE. Energy intake and energy provided by protein did not differ between the groups, while energy proportion obtained from carbohydrate was higher (PKU, 60 ± 2%; Control, 51 ± 2%; P < 0.05) and from fat lower (PKU, 24 ± 2%; Control, 35 ± 3%; P < 0.05) in the PKU than in the Control group.\ud \ud Conclusion: \ud People with PKU spent less time and expend less energy in moderate physical activity and have a higher intake of energy from CHO which may be involved in the underlying mechanisms of obesity in PKU.

BackgroundGut microbiotas play a pivotal role in host physiology and behaviour, and may affect host life-history traits such as seasonal variation in host phenotypic state. Generally, seasonal gut microbiota variation is attributed to seasonal diet variation. However, seasonal temperature and day length variation may also drive gut microbiota variation. We investigated summer–winter differences in the gut bacterial community (GBC) in 14 homing pigeons living outdoors under a constant diet by collecting cloacal swabs in both seasons during two years. Because temperature effects may be mediated by host metabolism, we determined basal metabolic rate (BMR) and body mass. Immune competence is influenced by day length and has a close relationship with the GBC, and it may thus be a link between day length and gut microbiota. Therefore, we measured seven innate immune indices. We expected the GBC to show summer–winter differences and to correlate with metabolism and immune indices.ResultsBMR, body mass, and two immune indices varied seasonally, other host factors did not. The GBC showed differences between seasons and sexes, and correlated with metabolism and immune indices. The most abundant genus (Lachnoclostridium 12, 12%) and associated higher taxa, were more abundant in winter, though not significantly at the phylum level, Firmicutes. Bacteroidetes were more abundant in summer. The Firmicutes:Bacteroidetes ratio tended to be higher in winter. The KEGG ortholog functions for fatty acid biosynthesis and linoleic acid metabolism (PICRUSt2) had increased abundances in winter.ConclusionsThe GBC of homing pigeons varied seasonally, even under a constant diet. The correlations between immune indices and the GBC did not involve consistently specific immune indices and included only one of the two immune indices that showed seasonal differences, suggesting that immune competence may be an unlikely link between day length and the GBC. The correlations between the GBC and metabolism indices, the higher Firmicutes:Bacteroidetes ratio in winter, and the resemblance of the summer–winter differences in the GBC with the general temperature effects on the GBC in the literature, suggest that temperature partly drove the summer–winter differences in the GBC in homing pigeons. Gut microbiotas play a pivotal role in host physiology and behaviour, and may affect host life-history traits such as seasonal variation in host phenotypic state. Generally, seasonal gut microbiota variation is attributed to seasonal diet variation. However, seasonal temperature and day length variation may also drive gut microbiota variation. We investigated summer–winter differences in the gut bacterial community (GBC) in 14 homing pigeons living outdoors under a constant diet by collecting cloacal swabs in both seasons during two years. Because temperature effects may be mediated by host metabolism, we determined basal metabolic rate (BMR) and body mass. Immune competence is influenced by day length and has a close relationship with the GBC, and it may thus be a link between day length and gut microbiota. Therefore, we measured seven innate immune indices. We expected the GBC to show summer–winter differences and to correlate with metabolism and immune indices.

Hypertension in obese and overweight patients is associated with an elevated resting metabolic rate (RMR). The aim of this study was to determine whether RMR is reduced in hypertensive patients treated with angiotensin‐converting enzyme inhibitors (ACEI) and blockers (ARB). The RMR was determined by indirect calorimetry in 174 volunteers; 93 (46.5 %) were hypertensive, of which 16 men and 13 women were treated with ACEI/ARB, while 30 men and 19 women with untreated hypertension served as a control group. Treated and untreated hypertensives had similar age, BMI, physical activity, and cardiorespiratory fitness. The RMR normalized to the lean body mass (LBM) was 15% higher in the untreated than ACEI/ARB‐treated hypertensive women (p = .003). After accounting for LBM, whole‐body fat mass, age, the double product (heart rate x systolic blood pressure), and the distance walked per day, the RMR was 2.9% lower in the patients taking ACEI/ARB (p = .26, treatment x sex interaction p = .005). LBM, age, and the double product explained 78% of the variability in RMR (R 2 = 0.78, p

Background: Observed associations of high-protein diets with changes in insulin resistance are inconclusive.Objectives: We aimed to assess associations of changes in both reported and estimated protein (PRep; PEst) and energy intake (EIRep; EIEst) with changes in HOMA-IR, glycated hemoglobin (HbA1c), and BMI (in kg/m2), in 1822 decreasing to 833 adults (week 156) with overweight and prediabetes, during the 3-y PREVIEW (PREVention of diabetes through lifestyle intervention and population studies In Europe and around the World) study on weight-loss maintenance. Eating behavior and measurement errors (MEs) of dietary intake were assessed. Thus, observational post hoc analyses were applied.Methods: Associations of changes in EIEst, EIRep, PEst, and PRep with changes in HOMA-IR, HbA1c, and BMI were determined by linear mixed-model analysis in 2 arms [high-protein-low-glycemic-index (GI) diet and moderate-protein-moderate-GI diet] of the PREVIEW study. EIEst was derived from energy requirement: total energy expenditure = basal metabolic rate × physical activity level; PEst from urinary nitrogen, and urea. MEs were calculated as [(EIEst - EIRep)/EIEst] × 100% and [(PRep - PEst)/PEst] × 100%. Eating behavior was determined using the Three Factor Eating Questionnaire, examining cognitive dietary restraint, disinhibition, and hunger.Results: Increases in PEst and PRep and decreases in EIEst and EIRep were associated with decreases in BMI, but not independently with decreases in HOMA-IR. Increases in PEst and PRep were associated with decreases in HbA1c. PRep and EIRep showed larger changes and stronger associations than PEst and EIEst. Mean ± SD MEs of EIRep and PRep were 38% ± 9% and 14% ± 4%, respectively; ME changes in EIRep and En% PRep were positively associated with changes in BMI and cognitive dietary restraint and inversely with disinhibition and hunger.Conclusions: During weight-loss maintenance in adults with prediabetes, increase in protein intake and decrease in energy intake were not associated with decrease in HOMA-IR beyond associations with decrease in BMI. Increases in PEst and PRep were associated with decrease in HbA1c.This trial was registered at clinicaltrials.gov as NCT01777893.

We investigated the effect of daily intake of yogurt drink fortified with either vitamin D alone or with added calcium on resting metabolic rate (RMR), thyroid hormones and homeostatic model assessment for insulin resistance in subjects with type 2 diabetes (T2D). A total of 75 adult subjects with T2D were randomly assigned to 1 of the 3 groups to receive either D-fortified yogurt drink (DY; 1000 IU vitamin D/day), Ca-D-fortified yogurt drink (CDY; 1000 IU vitamin D plus 500 mg calcium), or plain yogurt drink for 12 weeks. All assessments were done at the baseline and after the intervention. The concentrations of anti-thyroid peroxidase antibody (anti-TPO-Ab), intact parathyroid hormone (iPTH) and thyroid stimulating hormone (TSH) had declined significantly compared with baseline values only in the CDY group. The mean RMR increased in both DY and CDY groups (p < 0.001 for both). Also, changes of serum concentrations of 25-hydroxycalciferol (B = 2.96, 95% confidence interval (CI) = 1.3 to 4.6, p = 0.001) and iPTH (B = –2.41, 95% CI = –4.5 to –0.31, p = 0.025) remained significant predictors of RMR changes even after adjustment for changes of serum concentrations of TSH (B = –18.2, 95% CI = –61.7 to 25.2, p = 0.406). Daily intake of vitamin D together with calcium at physiological doses has attenuating effect on anti-TPO-Ab and TSH. Also, vitamin D with or without added calcium causes a significant thyroid-independent increase in RMR in euthyroid subjects with T2D. Registered at clinicaltrials.gov as NCT01229891. Novelty: Daily intake of vitamin D with calcium at physiological doses has attenuating effect on anti-TPO-Ab and TSH. Vitamin D with or without added calcium causes a thyroid-independent increase in RMR in euthyroid subjects with T2D.

Background: Thyroid disease and obesity are very common clinical conditions in the general population. They can occur together in the same subject, but their relationship does not seem to be exclusively stochastic. Aim: We critically reviewed the evidence of the literature in the attempt to provide explanation for this association, in order to understand the possible benefits of levothyroxine therapy in euthyroid obese patients. Results: A low energy expenditure rate can lead to obesity. Maintaining Basal Metabolic Rate (BMR) is the main cause of energy expenditure for the body, which is regulated by thermogenesis. Thyroid hormone receptors (TR) play different roles in the induction of thermogenetic mechanisms: TRα is fundamental to induce thermogenesis, TRβ triggers the expression of uncoupling protein 1(UCP1). Despite such mechanisms, there is not currently evidence to treat subjects suffering from obesity with thyroid hormones. Conclusion: Replacement therapy should be reserved to patients with obvious signs of subclinical or clinical hypothyroidism. Definitions: Basal metabolic rate (BMR) or basal energy expenditure (BEE): measurement obtained under total inactivity and controlled research conditions; resting energy expenditure (REE): measurement obtained when an individual is sitting quietly (is mildly higher than BMR/BEE).

Background Genetic correlations, causalities and pathways between large-scale complex exposures and ovarian and breast cancers need systematic exploration. Methods Mendelian randomisation (MR) and genetic correlation (GC) were used to identify causal biomarkers from 95 cancer-related exposures for risk of breast cancer [BC: oestrogen receptor-positive (ER + BC) and oestrogen receptor-negative (ER - BC) subtypes] and ovarian cancer [OC: high-grade serous (HGSOC), low-grade serous, invasive mucinous (IMOC), endometrioid (EOC) and clear cell (CCOC) subtypes]. Results Of 31 identified robust risk factors, 16 were new causal biomarkers for BC and OC. Body mass index (BMI), body fat mass (BFM), comparative body size at age 10 (CBS-10), waist circumference (WC) and education attainment were shared risk factors for overall BC and OC. Childhood obesity, BMI, CBS-10, WC, schizophrenia and age at menopause were significantly associated with ER + BC and ER - BC. Omega-6:omega-3 fatty acids, body fat-free mass and basal metabolic rate were positively associated with CCOC and EOC; BFM, linoleic acid, omega-6 fatty acids, CBS-10 and birth weight were significantly associated with IMOC; and body fat percentage, BFM and adiponectin were significantly associated with HGSOC. Both GC and MR identified 13 shared factors. Factors were stratified into five priority levels, and visual causal networks were constructed for future interventions. Conclusions With analysis of large-scale exposures for breast and ovarian cancers, causalities, genetic correlations, shared or specific factors, risk factor priority and causal pathways and networks were identified.

Objective Brown adipose tissue (BAT) controls metabolic rate through thermogenesis. As its regulatory factors during the transition from hyperthyroidism to euthyroidism are not well established, our study investigated the relationships between supraclavicular brown adipose tissue (sBAT) activity and physiological/metabolic changes with changes in thyroid status. Design Participants with newly diagnosed Graves’ disease were recruited. A thionamide antithyroid drug (ATD) such as carbimazole (CMZ) or thiamazole (TMZ) was prescribed in every case. All underwent energy expenditure (EE) measurement and supraclavicular infrared thermography (IRT) within a chamber calorimeter, as well as 18F-fluorodeoxyglucose (18F-FDG) positron-emission tomography/magnetic resonance (PET/MR) imaging scanning, with clinical and biochemical parameters measured during hyperthyroidism and repeated in early euthyroidism. PET sBAT mean/maximum standardized uptake value (SUV mean/max), MR supraclavicular fat fraction (sFF) and mean temperature (Tscv) quantified sBAT activity. Results Twenty-one (16 female/5 male) participants aged 39.5 ± 2.5 years completed the study. The average duration to attain euthyroidism was 28.6 ± 2.3 weeks. Eight participants were BAT-positive while 13 were BAT-negative. sFF increased with euthyroidism (72.3 ± 1.4% to 76.8 ± 1.4%; P < 0.01), but no changes were observed in PET SUV mean and Tscv. Significant changes in serum-free triiodothyronine (FT3) levels were related to BAT status (interaction P value = 0.04). FT3 concentration at hyperthyroid state was positively associated with sBAT PET SUV mean (r = 0.58, P = 0.01) and resting metabolic rate (RMR) (P < 0.01). Conclusion Hyperthyroidism does not consistently lead to a detectable increase in BAT activity. FT3 reduction during the transition to euthyroidism correlated with BAT activity.

The basal metabolic rate (BMR) accounts for 60–70% of the daily energy expenditure (DEE) in sedentary humans and at least 50% of the DEE in laboratory mice in the thermoneutral zone. Surprisingly, however, the significance of the variation in the BMR is largely overlooked in translational research using such indices as physical activity level (PAL), i.e., the ratio of DEE/BMR. In particular, it is unclear whether emulation of human PAL in mouse models should be carried out within or below the thermoneutral zone. It is also unclear whether physical activity within the thermoneutral zone is limited by the capacity to dissipate heat generated by exercise and obligatory metabolic processes contributing to BMR. We measured PAL and spontaneous physical activity (SPA) in laboratory mice from two lines, divergently selected towards either high or low level of BMR, and acclimated to 30 °C (i.e., the thermoneutral zone), 23 or 4 °C. The mean PAL did not differ between both lines in the mice acclimated to 30 °C but became significantly higher in the low BMR mouse line at the lower ambient temperatures. Acclimation to 30 °C reduced the mean locomotor activity but did not affect the significant difference observed between the selected lines. We conclude that carrying out experiments within the thermoneutral zone can increase the consistency of translational studies aimed at the emulation of human energetics, without affecting the variation in physical activity correlated with BMR.

Ott, T, Joyce, MC, and Hillman, AR. Effects of acute high-intensity exercise with the elevation training mask or hypoxicator on pulmonary function, metabolism, and hormones. J Strength Cond Res 35(9): 2486-2491, 2021-The elevation training mask (ETM) 2.0 is an increasingly popular hands-free respiratory muscle training modality proposing to mimic altitude; however, the degree to which this occurs has been questioned. The purpose of this study was to investigate the efficacy of this modality in comparison with using a hypoxicator (HYP) during acute aerobic exercise. Eight regularly active subjects (age: 25 ± 8 years; height: 166 ± 12 cm; body mass 64 ± 10 kg; and Vo2max: 46 ± 6 ml·kg-1·min-1) completed 3 trials, each including resting metabolic rate measurement, pulmonary function tests, and 13 sprint intervals at 90% Vo2max using either the HYP, ETM, or control. There was no significant difference in metabolism or heart rate between conditions. Fraction of expired air in the first second was greater after exercise (p = 0.02), while oxygen saturation was lower during exercise with the HYP (p < 0.001). Human growth hormone increased with exercise, but no differences were found between conditions; however, a trend was observed for higher growth hormone after exercise in HYP vs. ETM (p = 0.08). Elevation training mask does not seem to change acute pulmonary function, metabolism, heart rate, or oxygen saturation, indicating it likely does not create a hypoxic environment or mimic altitude.

High-intensity interval training (HIIT) promotes positive cardiometabolic and body composition changes. Essential amino acids (EAA) may support changes associated with HIIT, but evaluation of potential synergistic effects is lacking. The purpose of this study was to compare independent and combined effects of HIIT and EAA on total body composition and metabolism in men and women considered overweight/obese; an exploratory aim was to evaluate the modulatory effects of sex. Sixty-six healthy adults (50% female; Age: 36.7 ± 6.0 years; BMI: 32.0 ± 4.2 kg/m2) completed 8 weeks of: (1) HIIT, 2 days/weeks; (2) EAA supplementation, 3.6 g twice daily; (3) HIIT + EAA; or (4) control. Body composition, resting metabolic rate (RMR), substrate metabolism (respiratory exchange ratio; RER), and cardiorespiratory fitness were measured at baseline, 4 weeks, and 8 weeks; cardiometabolic blood markers were measured at baseline and 8 weeks. Differences between groups were assessed by linear mixed models covaried for baseline values, followed by 95% confidence intervals (CI) on adjusted mean change scores. There were no significant changes in body composition (p > 0.05) for any group. Changes in RER, but not RMR, occurred with HIIT (mean change; [95% CI]: − 0.04; [− 0.07, − 0.02]) and EAA (− 0.03; [− 0.06, − 0.01]) after 8 weeks. Cardiorespiratory fitness increased following 8 weeks of HIIT (+ 5.1 ml/kg/min [3.3,6.8]) and HIIT + EAA (+ 4.1 ml/kg/min [1.0,6.4]). Changes with HIIT + EAA were not significantly different from HIIT. There were no changes in cardiometabolic markers (p > 0.05) and no sex interaction (p > 0.05). HIIT is efficacious for promoting positive changes in cardiorespiratory fitness and resting substrate metabolism in adults considered overweight/obese. Addition of EAA did not significantly enhance HIIT-induced adaptations. ClinicalTrials.gov ID#NCT04080102.

Background It is important for sport scientists and health professionals to have estimative methods for energy demand during diferent physical activities. The metabolic equivalent of task (MET) provides a feasible approach for classifying activity intensity as a multiple of the resting metabolic rate (RMR). RMR is generally assumed to be 3.5 mL of oxygen per kilogram of body mass per minute (mL O2 kg−1 min−1), a value that has been criticized and considered to be overestimated in the older adult population. However, there has been no comprehensive efort to review available RMR estimations, equivalent to 1 MET, obtained in the older adult population. Objective The aim of this review was to examine the existing evidence reporting measured RMR values in the older adult population and to provide descriptive estimates of 1 MET. Methods A systematic review was conducted by searching PubMed, Web of Science, Scopus, CINAHL, SPORTDiscus, and Cochrane Library, from database inception to July 2021. To this end, original research studies assessing RMR in adults≥60 years old using indirect calorimetry and reporting results in mL O2 kg−1 min−1 were sought. Results Twenty-three eligible studies were identifed, including a total of 1091 participants (426 men). All but two studies reported RMR values lower than the conventional 3.5 mL O2 kg−1 min−1. The overall weighted average 1 MET value obtained from all included studies was 2.7±0.6 mL O2 kg−1 min−1; however, when considering best practice studies, this value was 11% lower (2.4±0.3 mL O2 kg−1 min−1). Conclusion Based on the results of this systematic review, we would advise against the application of the standard value of 1 MET (3.5 mL O2 kg−1 min−1) in people ≥ 60 years of age and encourage the direct assessment of RMR using indirect calorimetry while adhering to evidence-based best practice recommendations. When this is not possible, assuming an overall value of 2.7 mL O2 kg−1 min−1 might be reasonable. Systematic review registration: International Prospective Register of Systematic Reviews on 30 September 2020, with registration number CRD42020206440.

Total daily energy expenditure (“total expenditure”, MJ/d) reflects daily energy needs and is a critical variable in human health and physiology, yet it is unclear how daily expenditure changes over the life course. Here, we analyze a large, globally diverse database of total expenditure measured by the doubly labeled water method for males and females aged 8 days to 95 yr. We show that total expenditure is strongly related to fat free mass in a power-law manner and identify four distinct metabolic life stages. Fat free mass-adjusted daily expenditure accelerates rapidly in neonates (0-1yr) to ~46% above adult values at ~1 yr, declines slowly throughout childhood and adolescence (1-20 yr) to adult levels at ~20 yr, remains stable in adulthood (20-60 yr) even during pregnancy, and declines in older adults (60+ yr). These changes in total expenditure shed new light on human development and aging and should help shape nutrition and health strategies across the lifespan.

Objective of the study: to compare the values of basal metabolic rate and body composition in children with morbid and non-morbid obesity. Materials and methods of research: 87 adolescents with constitutionally exogenous obesity (CEO) were included in a prospective open-label observational single-center selective non-randomized uncontrolled study. The participants were divided into 2 groups: 43 with morbid obesity – mean age 15,7 years [14,9; 16,9], 20 boys (46%) and 23 girls (54%) and 44 with non-morbid obesity – the control group, mean age 15,3 years [10,1; 15,6], 19 boys (43%) and 25 girls (57%). All children underwent an assessment of body composition and basal metabolic rate. Results: adolescents with morbid obesity showed a statistically significantly greater amount of adipose tissue (51,5% [48,3; 56,2] vs 39,5% [35,4; 42,8], p

Background: The purpose of this study was to investigate the accuracy of the published prediction equations for determining level overground walking energy cost in young adults. Methods: In total, 148 healthy young adults volunteered to participate in this study. Resting metabolic rate and energy expenditure variables at speeds of 4, 5, and 6 km/h were measured by indirect calorimetry, walking energy expenditure was estimated by 3 published equations. Results: The gross and net metabolic rate per mile of level overground walking increased with increased speed (all P P Conclusions: The Weyand et al equation appears to be the most suitable for the prediction of overground walking energy expenditure in young adults.

Malnutrition in cirrhosis is associated with significant morbidity and mortality, and an accurate energy prescription is central to effective nutrition therapy. Indirect calorimetry is recommended to determine energy requirements, with novel handheld devices offering a simpler and lower cost assessment. This review summarises the published literature from 2010 to 2020 regarding the measurement of energy expenditure in patients with liver cirrhosis. Twelve studies involving 1039 patients were identified. Results indicate discordance between predicted and measured requirements in cirrhosis, with both underestimation (58%, n = 7) and overestimation (36%, n = 4) reported. The prevalence of hypermetabolism ranged from 5.3 to 58.3%. Heterogeneity in patient cohort, liver disease severity, and nutritional status impact observed results. In three studies involving handheld calorimetry devices, moderate agreement with metabolic carts was reported, with superior results to predictive equations when determining resting metabolic rate. Predictive equations are inaccurate in cirrhosis, and indirect calorimetry should be used to guide nutrition interventions. Handheld devices are a promising tool to embed in clinical practice with further studies required to validate their use.

Sexual size dimorphism can vary in direction and magnitude across populations, but the extent to which such intraspecific variation is associated with sex and population differences in underlying metabolic processes is unclear. We compared resting metabolic rates (RMRs) of brown anole lizards (Anolis sagrei) from two island populations in the Bahamas (Eleuthera and Great Exuma) that differ in the magnitude of male-biased sexual size dimorphism. Whereas females from each population exhibit similar growth rates and body sizes, males from Great Exuma grow more quickly and attain larger body sizes than males from Eleuthera. We found that these population differences in growth of males persisted in captivity. Therefore, we predicted that males from each population would differ in RMR, whereas females would not. Consistent with this prediction, we found that RMR of males from Eleuthera was higher than that of males from Great Exuma, particularly at higher temperatures. As predicted, RMR of females did not differ between populations. Despite this apparent sex-specific trade-off between growth rate and RMR at the population level, we found a positive relationship between growth rate and RMR at the individual level. The fact that Great Exuma males maintain lower RMR than Eleuthera males, despite their greater absolute growth rates and the positive relationship between RMR and growth rate across individuals, suggests that Great Exuma males may have lower baseline metabolic demands and/or greater growth efficiency than Eleuthera males. Our results call attention to sex-specific divergence in metabolism as a potential mechanism for intraspecific divergence in sexual size dimorphism.

Skeletal muscle is the organ of locomotion, its optimal function is critical for athletic performance, and is also important for health due to its contribution to resting metabolic rate and as a site for glucose uptake and storage. Numerous endogenous and exogenous factors influence muscle mass. Much of what is currently known regarding muscle protein turnover is owed to the development and use of stable isotope tracers. Skeletal muscle mass is determined by the meal- and contraction-induced alterations of muscle protein synthesis and muscle protein breakdown. Increased loading as resistance training is the most potent nonpharmacological strategy by which skeletal muscle mass can be increased. Conversely, aging (sarcopenia) and muscle disuse lead to the development of anabolic resistance and contribute to the loss of skeletal muscle mass. Nascent omics-based technologies have significantly improved our understanding surrounding the regulation of skeletal muscle mass at the gene, transcript, and protein levels. Despite significant advances surrounding the mechanistic intricacies that underpin changes in skeletal muscle mass, these processes are complex, and more work is certainly needed. In this article, we provide an overview of the importance of skeletal muscle, describe the influence that resistance training, aging, and disuse exert on muscle protein turnover and the molecular regulatory processes that contribute to changes in muscle protein abundance. © 2021 American Physiological Society. Compr Physiol 11:2249-2278, 2021.

Decline in cardiac high-energy phosphate metabolism [phosphocreatine-to-ATP (PCr/ATP) ratio] and whole body metabolism increase the risk of heart failure and metabolic diseases. The aim of the present study was to assess the relationship between PCr/ATP ratio and measures of body metabolic function. A total of 35 healthy women (56±14.0 years of age) underwent cardiac 31P magnetic resonance spectroscopy to assess PCr/ATP ratio – an index of cardiac high-energy phosphate metabolism. Fasting and 2-hour glucose levels were assessed using oral glucose tolerance test. Indirect calorimetry was performed to determine oxygen consumption and resting metabolic rate. There were no significant relationships between PCr/ATP ratio and resting metabolic rate (r=-0.09, p=0.62), oxygen consumption (r=-0.11, p=0.54), fasting glucose levels (r=-0.31, p=0.07), and 2-hour plasma glucose (r=-0.10, p=0.58). Adjusted analysis for covariates including age, body mass index, fat mass, and physical activity, had no significant influence on the relationship between PCr/ATP ratio and body metabolism. In conclusion, the lack of relationship between cardiac PCr/ATP ratio, glucose control and metabolic rate may suggest that overall metabolic function does not influence cardiac high-energy phosphate metabolism.

The human body, even at rest, needs energy to perform necessary physiological functions. Strict conditions are required for measuring basal metabolic rate (BMR). Many factors that have a direct impact on BMR including the condition of autonomic nervous. All living systems are affected by external and internal environments. One factor in the external environment is the Earth’s magnetic field, which fluctuates over a wide frequency range. A series of studies indicate that low frequency magnetic fields can affect cellular mitochondrial activity and impacts every cell’s metabolism. Information on gas metabolism during respiration was obtained by indirect calorimetry using a system where the gas flow was continuously analyzed. Time varying local Earth magnetic field data were recorded at a magnetometer site located in Lithuania using 2 induction coil magnetometers. For all magnetic field data, power spectral density PSD was calculated for every hour (fast Fourier transformation) in the band between 0.32 to 36 Hz. Investigations of metabolic rate were performed in Lithuanian during 2016-2020 years. We assessed 395 persons: 116 men and 279 women. Conclusions: 1) Oxygen consumption has significant negative correlation with local geomagnetic field activity; 2) Metabolic rate decreases with increases in local geomagnetic time varying field power; 3) Measured metabolic rate decreases with increase of local geomagnetic field power.

PURPOSE: Low-carbohydrate diet (LCD) has been used for weight loss and preventing obesity, but the association of adherence to LCD and resting metabolic rate (RMR) has not been investigated. This study aimed to investigate the association between the low-carbohydrate-diet score (LCDS) and RMR among Iranian adults. METHODS: This cross-sectional study was conducted on 270 Iranian adults 18–70 y of age. To assess dietary intakes, participants completed a validated food frequency questionnaire. The LCDS was calculated based on carbohydrate, protein and fat intake, expressed as a percentage of energy. The higher score indicates the lower carbohydrate and the higher protein and fat intake. RMR was measured by indirect calorimetry after an overnight fast. RESULTS: Multivariate-adjusted means showed that RMR significantly increased across tertiles (p = 0.041). However, there were no significant differences in the mean of fat mass (FM) and fat-free mass (FFM) across tertiles of LCDS (p = 0.986 and p = 0.621, respectively). Also LCDS and RMR (r = 0.14, p = 0.021) were found to be correlated, but LCDS and FFM (r = 0.06, p = 0.323), FM (r = −0.05, p = 0.412), had no statistically significant correlation. RMR had a significant positive association with LCDs in the crude model (β = 18.81, 95% CI: 2.55, 35.07, P = 0.024). Moreover, after controlling for covariates this association changed to non-significant (β = −0.14, 95% CI: −7.05, 19.25, P = 0.03). CONCLUSION: Adherence to diets lower in carbohydrates and higher in fat and protein were associated with higher RMR. Further studies with a larger sample size are needed to confirm these findings.

Rodriguez, C, Harty, PS, Stratton, MT, Siedler, MR, Smith, RW, Johnson, BA, Dellinger, JR, Williams, AD, White, SJ, Benavides, ML, and Tinsley, GM. Comparison of indirect calorimetry and common prediction equations for evaluating changes in resting metabolic rate induced by resistance training and a hypercaloric diet. J Strength Cond Res XX(X): 000-000, 2021-The ability to accurately identify resting metabolic rate (RMR) changes over time allows practitioners to prescribe appropriate adjustments to nutritional intake. However, there is a lack of data concerning the longitudinal utility of commonly used RMR prediction equations. The purpose of this study was to evaluate the validity of several commonly used prediction equations to track RMR changes during a hypercaloric nutritional intervention and supervised resistance exercise training program. Twenty resistance-trained men completed the study. The protocol lasted 6 weeks, and subjects underwent RMR assessments by indirect calorimetry (IC) preintervention and postintervention to obtain reference values. Existing RMR prediction equations based on body mass (BM) or dual-energy X-ray absorptiometry fat-free mass (FFM) were also evaluated. Equivalence testing was used to evaluate whether each prediction equation demonstrated equivalence with IC. Null hypothesis significance testing was also performed, and Bland-Altman analysis was used alongside linear regression to assess the degree of proportional bias. Body mass and FFM increased by 3.6 ± 1.7 kg and 2.4 ± 1.6 kg, respectively. Indirect calorimetry RMR increased by 165 ± 97 kcal·d-1, and RMR:FFM increased by 5.6 ± 5.2%. All prediction equations underestimated mean RMR changes relative to IC, with magnitudes ranging from 75 to 155 kcal·d-1, while also displaying unacceptable levels of negative proportional bias. In addition, no equation demonstrated equivalence with IC. Common RMR prediction equations based on BM or FFM did not fully detect the increase in RMR observed with resistance training plus a hypercaloric diet. Overall, the evaluated prediction equations are unsuitable for estimating RMR changes in the context of this study.

The resting metabolic rate (RMR) is one of the most representative components of total daily energy expenditure (TDEE). Multiple equations have been developed to estimate RMR, but none have been described for Para-Athletes. This study aimed to; i) develop and validate new RMR estimation models from anthropometric variables; and ii) explore the level of agreement between the RMR determined by indirect calorimetry (IC) and the developed models, as well as a selection of existent estimation models in Para-Athletes. Fifteen young Paralympic swimmers (age, 18.7±6.5 years) underwent assessments of RMR by IC and anthropometric batteries. Four RMR estimation models (M1-M4) were developed. The anthropometric variables which explained most of the variance were biacromial breadth (M3-37%), stature (M1-45%; M2-49%), and estimated stature from half arm span (M4-24%). However, the neck girth corrected by the submandibular skinfold entered in all four models. The 95% limits of agreement between IC and M3 equation (best performance model) ranged from -142.02 to 172.39 kcal×day-1 (bias 15.19 kcal×day-1). Concerning the commonly used equations, HarrisBenedict equation was the most consistent when compared to IC. The results of this study suggest four novel RMR equations that may assist in the estimation of energy requirements in elite Para-Athletes.

Energy Availability and RED-S Risk Factors in Competitive, Non-elite Male Endurance Athletes Amy R Lane1, Anthony C Hackney()1, Abbie E Smith-Ryan1, Kristen Kucera1, Johna K Register-Mihalik1 and Kristin Ondrak1 1Department of Exercise & Sport Science, University of North Carolina, Chapel Hill, NC 27599, USA © The Authors Abstract Relative Energy Deficiency in Sport (RED-S) is predicated on the assumption that low energy availability (EA) induces deficiencies-dysfunction in multiple physiologic systems. However, research on RED-S and EA in male athletes is limited in comparison to women. The aim of this study is to investigate EA and the risk factors for RED-S, and their potential associations in non-elite male endurance athletes. Laboratory assessments for resting metabolic rate (RMR), bone mineral density (BMD), blood hormonal biomarkers and maximal aerobic capacity were conducted on 60 competitive, recreationally trained male endurance athletes (age=43.4±11.6 years [mean±SD], training=10.9±2.7 h/wk, 7.1±8.8 years). Participants provided 7-days of training logs and 4-days of diet records. Diet and training records were used to calculate EA. Correlations were used to examine associations between EA and RMR, BMD, stress fractures and reproductive, metabolic and bone biomarkers. Mean EA was 28.7±13.4 kcal/kg fat free mass (FFM), which categorized our sample as low EA (based upon published criterion, < 30 kcal/kg FFM) and at a high risk for RED-S. Hormonal and bone biomarkers were in normal clinical ranges, even though EA was low. The only interesting significant association was EA being negatively associated with total body BMD (r=–0.360, P=0.005), opposite of expectations. On average our subjects displayed a state of low EA based upon the criterion which has been primarily developed from female-based research. Nonetheless, our participants displayed no major hormonal or bone health disturbances found in athletes diagnosed with RED-S. A value of < 30 kcal/kg FFM to diagnose low EA may not be appropriate for non-elite endurance trained men.

Individual variations in metabolic rate, locomotion capacity and hypoxia tolerance and their relationships were investigated in three cyprinid species [crucian carp (Carassius auratus), common carp (Cyprinus carpio) and qingbo (Spinibarbus sinensis), in 60 individuals of each species]. Either the active metabolic rate (AMR) and critical swimming speed (Ucrit) (30 individuals) or critical oxygen tension (Pcrit) and loss of equilibrium (LOE) (30 individuals) were measured in each species after measuring the resting metabolic rate (RMR). Both the AMR and Ucrit were found to be significantly and positively correlated with the RMR in all three cyprinid species, indicating that high-RMR individuals have high aerobic capacity and thus good swimming performance. Pcrit was positively correlated with the RMR in all three species, whereas the LOE was highly positively correlated, weakly positively correlated and not correlated with the RMR in qingbo, common carp and crucian carp, respectively, possibly due to specialized morphological and biochemical adaptations involved in hypoxia tolerance in crucian and common carp. Crucian carp showed relatively poor swimming performance, i.e., a low Ucrit (relatively high variation), strong hypoxia tolerance, and low LOE (relatively low variation); qingbo showed relatively good swimming performance (relatively low variation) and weak hypoxia tolerance (relatively high variation); and common carp showed moderate swimming performance and relatively strong hypoxia tolerance (moderate variation). These interspecific differences may be due to the different lifestyles of these cyprinid fishes based on their associated fast-slow-flow regime and are outcomes of long-term selection.

Rachel A Tinius,1 Kristin Yoho,1 Maire M Blankenship,2 Jill M Maples3 1School of Kinesiology, Recreation, and Sport, Western Kentucky University, Bowling Green, KY, 42101, USA; 2School of Nursing and Allied Health, Western Kentucky University, Bowling Green, KY, 42101, USA; 3Department of Obstetrics and Gynecology, University of Tennessee Graduate School of Medicine, Knoxville, TN, 37920, USACorrespondence: Rachel A TiniusSchool of Kinesiology, Recreation, and Sport, Western Kentucky University, Bowling Green, KY, 42101, USATel +1 270-745-5026Email Rachel.tinius@wku.eduBackground: Metabolic dysfunction after pregnancy may have serious consequences for a new mother. The purpose of the study was to characterize basic changes that occur in metabolic profiles from late pregnancy through 4– 6 months postpartum. A secondary purpose was to determine metabolic factors that may be contributing to postpartum weight retention.Methods: Participants (n=25) came in for 2 visits: late pregnancy (∼ 34 weeks gestation) and postpartum (4-6 months). Resting metabolic rate (RMR), respiratory quotient (RQ), and substrate oxidation values were assessed for 15 minutes during fasted conditions. Blood was drawn and skinfold anthropometry was performed to assess additional outcomes (inflammation, insulin resistance, lipid profiles, body composition). The participants completed a number of surveys that examined other lifestyle and demographic data of interest. At the postpartum visit, additional assessments regarding sleep and breastfeeding habits were administered.Results: RMR was lower during postpartum (1517.2± 225.1 kcal/day) compared to pregnancy (1867.9± 302.6 kcal/day) (p< 0.001), and remained lower when expressing RMR per kg body weight (postpartum: 22.3± 2.7 vs pregnant: 23.7± 3.4 kcal/kg, (p=0.034). Relative RMR (RMR per kg body weight) was negatively correlated to insulin resistance (HOMA-IR) during postpartum (r=− .463, p=0.034). Maternal HOMA-IR, inflammation (CRP), triglycerides (TAG), and carbohydrate oxidation were all positively correlated to postpartum weight retention (HOMA-IR: r=0.617, p=0.004; CRP: r=0.477, p=0.039, TAG: r=0.463, p=0.040; Carbohydrate Oxidation: (r=0.469, p=0.018).Conclusion: Metabolic rate is lower during postpartum compared to pregnancy, and may be connected to insulin resistance. Maternal insulin resistance, inflammation, blood lipids, and substrate metabolism are all related to postpartum weight retention.Keywords: postnatal, metabolic rate, insulin resistance, inflammation

To observe the effects of acupoint thread-embedding therapy and low-carbohydrate diet therapy on obese patients with food addiction. Sixty-five eligible patients were randomized into a thread-embedding group of 33 cases and a diet group of 32 cases to respectively receive 12-week treatment. Before treatment, after treatment and at 6-month follow-up, the two groups were observed and compared in terms of body mass (BM), waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR), body mass index (BMI), body fat rate (BFR), basal metabolic rate (BMR) and Yale food addiction scale version 2.0 (YFAS 2.0). At the end of treatment, there were no significant differences in the general efficacy, and the improvements in BM, BMI, WC, HC, WHR and BFR between the thread-embedding group and diet group (all P>0.05). At follow-up, the thread-embedding group showed more significant improvements in all the aforementioned indicators compared with the diet group except HC (all P

Endotherms at high altitude face the combined challenges of cold and hypoxia. Cold increases thermoregulatory costs, and hypoxia may limit both thermogenesis and aerobic exercise capacity. Consequently, in comparisons between closely related highland and lowland taxa, we might expect to observe consistent differences in basal metabolism (BMR), maximal metabolism (MMR), and aerobic scope. Broad-scale comparative studies of birds reveal no association between BMR and native elevation, and altitude effects on MMR have not been investigated. We tested for altitude-related variation in aerobic metabolism in 10 Andean passerines representing five pairs of closely related species with contrasting elevational ranges. Mass-corrected BMR and MMR were significantly higher in most highland species relative to their lowland counterparts, but there was no uniform elevational trend across all pairs of species.Summary statementWe tested for altitude-related variation in aerobic metabolism in species pairs with contrasting elevational ranges. Metabolic rates were significantly higher in most highland species but there was no uniform elevational trend.

Background: We examined the effects of exercise training on resting metabolic rate (RMR), and whether changes in body composition are associated with changes in RMR in adolescents with overweight and obesity. Methods: One hundred forty adolescents (12–18 years, BMI ≥85th percentile) participated in randomized exercise trials (3–6 months) at UPMC Children's Hospital of Pittsburgh (18 control, 51 aerobic, 50 resistance, and 21 combined aerobic and resistance exercise). All participants had RMR assessments by indirect calorimetry after a 10–12 hour overnight fast, and body composition by magnetic resonance imaging and dual-energy X-ray absorptiometry. Results: There were no significant changes in RMR (kcal/day) between exercise groups vs. controls (p > 0.05). All exercise groups decreased visceral fat (−0.2 ± 0.02 kg; p 0.05), was a significant determinant of changes in RMR, independent of exercise modality (p = 0.04). Conclusion: Although exercise modality was not associated with changes in RMR, change in FFM, but not skeletal muscle or FM, was a significant correlate of changes in RMR in adolescents with overweight and obesity. Clinicaltrials.gov registration numbers: NCT00739180, NCT01323088, NCT01938950.

In the modern world with the advent of devices that facilitate work (computer, technical equipment) has decreased sharply motor activity of people compared to previous decades. This, in the end, leads to a decrease in human functionality, as well as various diseases. Today, purely physical work does not play a significant role, it is replaced by mental. Intellectual work dramatically reduces the efficiency of the body. Lack of human energy expenditure leads to inconsistencies in the functioning of individual systems (muscular, skeletal, respiratory, cardiovascular) and the body as a whole with the environment, as well as reduced immunity and impaired metabolism. Exercise affects all muscle groups, joints, ligaments, which become strong, increase muscle volume, elasticity, strength and rate of contraction. Increased muscle activity forces the heart, lungs and other organs and systems of our body to work with additional load, thereby increasing the functional capabilities of man, his resistance to adverse environmental influences. Regular exercise primarily affects the musculoskeletal system, muscles. When you exercise, the muscles generate heat, to which the body responds by increased sweating. During exercise, blood flow increases: the blood brings oxygen and nutrients to the muscles, which in the process of life break down, releasing energy. When movements in the muscles additionally open reserve capillaries, the amount of circulating blood increases significantly, which causes an improvement in metabolism. In response to the reaction of the human body to exercise, the first place is occupied by the influence of the cerebral cortex on the regulation of the functions of the basic systems: there is a change in the cardiorespiratory system, gas exchange, metabolism, and others. Exercises enhance the functional restructuring of all parts of the musculoskeletal system, cardiovascular and other systems, improve tissue metabolism. Under the influence of moderate physical activity increases the efficiency of the heart, hemoglobin and red blood cell count, increases the phagocytic function of the blood. Improves the function and structure of the internal organs, improves chemical processing and promotion of food in the intestine. The combined activity of muscles and internal organs is regulated by the nervous system, the function of which is also improved by regular exercise. If the muscles do not work - their nutrition deteriorates, volume and strength decrease, elasticity and resilience decrease, they become weak, sluggish. Restrictions in movement (hypodynamia), passive lifestyle lead to various pre-pathological and pathological changes in the human body. So, the American doctors, having deprived volunteers of movements by imposing of high plaster and having kept to them a normal diet, were convinced that in 40 days at them muscle atrophy began and fat has accumulated. At the same time increased the reactivity of the cardiovascular system and decreased basal metabolism. However, during the next 4 weeks, when the subjects began to move actively (with the same diet), the above phenomena were eliminated, the muscles were strengthened and hypertrophied. Thus, due to physical exertion, recovery was possible both in functional and structural terms. Exercise has a multifaceted effect on the human body, increasing its resistance to adverse environmental influences. For example, physically trained people have better tolerance to oxygen starvation than untrained people. High ability to work at increase of body temperature over 38 ° C during physical exertions is noted. It has been noticed that radiologists who exercise have a lower degree of influence of penetrating radiation on the morphological composition of the blood. Animal experiments have shown that regular muscle training slows the development of malignant tumors. Regular exercise in physical education promotes good health and affects the various physiological adaptations of the neuromuscular, cardiovascular and respiratory systems of the human body. Types of physical activities are considered: aerobic, anaerobic, interval and hypoxic physical activities.

Context Mice bred to be genetically different in feed efficiency were used in this experiment designed to help improve our knowledge of the biological basis of variation in feed efficiency between individual animals. Aims This experiment used mice to explore the metabolic basis of genetic variation in feed efficiency in the growing animal. Methods Mice bred to differ in residual feed intake (RFI) recorded over a postweaning test were used. After 11 generations of divergent selection, mice in groups were tested for RFI from 6 to 8, 8 to 10, and 10 to 12 weeks of age, and measured for traits describing the ability to digest feed, body composition, protein turnover, basal and resting metabolic rate, and level of activity. Key results Compared with the low-RFI (high efficiency) line mice, high-RFI mice consumed 28% more feed per day over their RFI-test, were no heavier, were leaner (16% less total fat per unit of bodyweight), did not differ in the fractional synthesis rate of protein in skeletal muscle or in liver, and had similar basal metabolic rates at 33°C. On an energy basis, the selection lines did not differ in energy retained in body tissue gain, which represented only 1.8% of metabolisable energy intake. The remaining 98.2% was lost as heat. Of the processes measured contributing to the higher feed intake by the high-RFI mice, 47% of the extra feed consumed was lost in faeces and urine, activity was 84% higher and accounted for 24%, the cost of protein gain was 6% higher and accounted for 2%, and the energy cost of digesting and absorbing the extra feed consumed and basal heat production could have accounted for 11 and 15% each. Conclusions Selection for low RFI (high efficiency) in mice was accompanied by an increase in body fat, an improvement in the process of digestion, a lower rate of protein turnover and a much lower level of activity. Selection did not result in major change in basal metabolic rate. Implications This experiment with mice provided new information on the biological basis of genetic differences in feed efficiency. The experiment investigated the relative importance of major energy-consuming metabolic processes and was able to quantify the responses in protein turnover and level of activity, being responses in energy-consuming processes that have proven difficult to quantitatively demonstrate in large farm animals.

Energy is a universal resource essential for all life functions. The rate of transformation of energy into an organism, and the energetic investment into reproduction, determines population and ecological-level processes. Several hypotheses predicted that the ecological expansion and size of the geographic distribution of a species are shaped by, among other factors, metabolic performance. However, how organismal energetic characteristics contribute to species geographic range size is poorly understood. With phylogenetic comparative methods whether energetic maintenance costs (basal metabolic rate, BMR), aerobic capacity (maximum exercise metabolic rate, VO2 max), summit thermoregulation (summit metabolic rate, VO2 sum) and the ability to sustain energy provisioning (daily energy expenditure, DEE) determine the distribution of mammalian species range sizes was tested. Both basal and maximum exercise metabolic rates (accounting for body mass), but not summit thermogenic metabolic rate, were positively associated with species range sizes. Furthermore, daily energy expenditure (accounting for body mass) was positively associated with species ranges. Body mass (accounting for energetic maintenance) was negatively related to range sizes. High aerobic exercise capacity, aiding mobility such as running and dispersal, and high sustained energy provisioning, aiding reproductive effort such as pregnancy, lactation and natal dispersal, can facilitate the establishment of large mammalian geographic ranges. Consequently, the pace of organismal physiological processes can shape important ecological and biodiversity patterns by setting limits to species' range sizes.

By investigating the status quo of the swimming training market in a certain area, we can obtain information on the current development of the swimming training market in a certain area and study the laws of the development of the market so as to provide a theoretical basis for the development of the market. This paper designs an evaluation algorithm suitable for swimming training based on the improved AlexNet network. The algorithm model uses a 3 × 3 size convolution kernel to extract features, and the pooling layer uses a nonoverlapping pooling strategy. In order to accelerate the network convergence, the model introduces batch normalization technology. The algorithm uses data augmentation technology to expand the data set, including rotation and random erasure, to a certain extent alleviating the problem of overfitting. The results of the study showed that there were no significant differences in fat, minerals, protein, body mass index, basal metabolic rate, and total energy expenditure in the body composition ratios of children in the convolutional neural network assessment group and the control group, while muscle and total body water were not significantly different. However, there are significant differences in fat-free body weight and muscle strength of various segments of the body, among which there are very significant differences in muscle strength of lower limbs in each segment of the body. There were no significant differences in minerals, body mass index, basal metabolic rate, total energy expenditure, and lower limb muscle strength in the body composition ratios of men and women in the convolutional neural network assessment group. There are significant differences in body weight, upper limb muscle strength, and trunk muscle strength. There were no significant differences in the proportions of body composition between men and women in the control group, except for fat and protein.

Erythroderma (exfoliative dermatitis) associates with important metabolic changes that include an enhancement in energy expenditure. The key components to total energy expenditure (TEE) include basal metabolic rate (~68% of TEE), physical activity (~22% of TEE) and thermic effect of food (~10% of TEE). In the erythrodermic state, there are likely multiple contributors to the increase in basal metabolic rate such as ‘caloric drain’ resulting from increased evaporation of water from enhanced transepidermal water loss, increased activity of the cardiovascular system (including high‐output cardiac failure), increased non‐shivering thermogenesis and hormonal changes (such as hypercortisolaemia). A change to patient’s level of physical activity and appetite as a result of ill health status may further impact on their total energy expenditure and energy consumption. In part two of this two part concise review, we explore the key constituents of energy homeostasis, the potential mechanisms impacting on energy homeostasis in erythroderma and suggest much needed dietetic management strategies for this important condition.\ud \ud

Time-dependent changes in body composition and the levels of hormones involved in regulating energy metabolism and eating behavior were studied in ten healthy volunteers who were exposed to dry immersion (DI) for 21 days without the use of countermeasures to prevent the negative effects of the experimental conditions. Bioimpedance analysis (BIA) was used to assess the body composition in the test subjects. The proportion of lean mass decreased, while the fat component increased in the subjects under the influence of factors of 21-day DI. Cluster analysis isolated two equal homogeneous groups of subjects with a reduced group variability of the parameters of body composition and systemic regulation of energy metabolism. A significant decrease (p < 0.05) in relative skeletal muscle mass (SMM%) was observed after 21-day DI in the group with a higher relative body fat mass (FM), a lower relative fat-free mass (FFM), and a higher basal metabolic rate. SMM was stable, while SMM% increased (p < 0.05) after 21-day DI in the group with a lower relative FM, a higher FFM, and a lower basal metabolic rate. A significant increase in blood insulin was observed during DI in this group. Leptin and triglyceride concentrations differed between the groups in different periods of the experiment.

Background Although over one hundred equations have been developed to predict the energy expenditure of individuals, none are sensitive to weight change in assessment of resting metabolic rate (RMR) before and after weight loss. Objective To formulate adjusted equations for overweight and obese individuals and to compare their accuracy with existing prediction RMR equations before and after weight loss. Subjects/materials This is historical prospective study. Participants included 39 overweight and obese men and women before and after losing 10–20% from baseline weight on a diet and physical activity regimen for at least three months. Pre and post weight loss measured RMR results were compared to estimated RMR using several existing prediction equations: Harris and Benedict, Ravussin and Bogardus, and Mifflin et al. To improve the accuracy of these prediction equations, we suggest new equations adjusted for weight loss, based on measured RMR and evaluated their accuracy. Results Pre and post weight loss data indicated: significant fat reduction in both genders; reduction in free-fat mass only in men, and a significant decrease in measured RMR only in women. Our suggested equations were the most accurate and closest to measured RMR in both genders, in comparison to the Harris and Benedict, Ravussin and Bogardus, and Mifflin et al equation results. Estimated RMR using the latter equations was significantly lower than measured RMR in both genders at pre and post weight loss (P Conclusions This study highlights the need for adjusting RMR equations before and after weight loss in overweight and obese individuals. Further research is needed to validate our suggested equations.

To assess serum vitamin D trend from baseline to 12 months after one anastomosis gastric bypass (OAGB).In this observational cohort analysis of longitudinal data, we assessed the trend of serum vitamin D, and its associations with anthropometric, and biochemical measurements in 98 patients undergoing OAGB in a bariatric surgery center. All participants were on800 IU/day vitamin D supplementation.Vitamin D, lipid profile, creatinine, and albumin levels significantly improved at 12 months post-surgery. Vitamin D concentrations significantly increased from 26.52 ± 12.32 to 54.52 ± 27.90 ng/mL at 12 months. The correlations between vitamin D concentrations and weight, body mass index, lipid profile, ferritin, glycemic indices, and albumin were not significant. In addition, the correlations between vitamin D and parathormone, vitamin D receptor, calcium, phosphorus, body composition, and basal metabolic rate (BMR) did not reach the threshold of statistical significance at 12 months following bariatric surgery. Although there was a significant correlation between body weight and body composition (P 0.001) and basal metabolic rate (BMR) (r = 0.762, P 0.001) at 12 months, there were no significant correlations between weight change percent and body composition (P 0.05), BMR (r = -0.101, P = 0.350), and vitamin D (r = 0.120, P = 0.271) at 12 months.Our results showed that supplementation of vitamin D with dosage of800 IU/day is sufficient for prevention of vitamin D deficiency within 12 months after OAGB surgery. Note: This data is mandatory.

Summary Background & aims Time-restricted feeding (TRF) studies have been summarized in previous systematic reviews, but these were not specific for individuals with excess weight and studies involving early time-restricted feeding (eTRF). This meta-analysis aimed to evaluate the effect of eTRF on the metabolic profile of adults with excess weight. Methods Data were extracted from MEDLINE, CENTRAL, LILACS, Web of Science, ClinicalTrials.gov , OpenGrey.eu, Greylit, and by manual search. Randomized controlled trials in which the participants were older than 18 years, with a body mass index greater than 25 kg/m2 and that were allocated in an intervention with eTRF were included. The studies should have assessed any of the following outcomes from the metabolic profile: resting metabolic rate, triacylglycerol, total cholesterol, HDL-cholesterol, and LDL-cholesterol, fasting blood glucose, insulin, HOMA-IR, C-reactive protein, Interleukin-6, cortisol, leptin, Ghrelin, Peptide YY and glucagon-like peptide, hemodynamic parameters, and appetite. The risk of bias was assessed using the Cochrane collaboration tool. Publication bias was examined with a funnel plot and Egger's test. GRADE was used to assess the overall quality of evidence. Results Ten articles from nine randomized clinical trials, with 264 individuals, were included in qualitative analysis and eight articles with 184 individuals were included in the meta-analysis. There were significant effects on the fasting blood glucose (WMD: −2.75; 95% CI [-4.59; −0.90] mg/dL; p (WMD: −0.50; 95% CI [-0.82; −0.19]; p Conclusions Although the eTRF regimen seems to have a beneficial effect on the fasting blood glucose and HOMA-IR of individuals with excess weight, the results of this meta-analysis should be analyzed with caution due to the low-quality evidence.

Summary: Background & Aims: The better equation to predict resting metabolic rate (pRMR) to use for overweight individuals mainly after weight loss is unclear. This study aimed to identify the best equation to pRMR in overweight adult women before and after a nutritional intervention aiming to lose weight. Methods: Thirty overweight adult women were enrolled in this study. Subjects underwent 6-month energy-restricted diet intervention. Anthropometrics and body composition measures were evaluated. Nine equations that are widely used to pRMR were performed based on anthropometric and body composition parameters. Measured RMR (mRMR) was obtained by indirect calorimetry. A new equation to predict resting metabolic rate (npRMR) was also developed by multiple regression analysis based on anthropometric and body composition variables. The validity of the equations was investigated through comparisons, accuracy, and agreement tests. Results: Before the nutrition intervention, only the Mifflin equation was similar to mRMR, with a mean difference of 12kcal and 83% of accuracy. The mean weight loss was 4.2% after 6 months. Following weight loss, only the Owen equation was similar to mRMR, with a mean difference of −33 kcal. However, this equation showed low accuracy (63%). All the others equations showed reduction of accuracy, increase of bias and overestimation of RMR. A npRMR was calculated, and this showed a lower mean difference to mRMR with 70% of accuracy. Conclusions: Out of the nine resting metabolic rate equations evaluated only the Mifflin equation was similar to mRMR before intervention. Interestingly, after weight loss none of the assessed equations were reliable to pRMR. Based on that we propose a new equation that showed greater accuracy and lower mean difference when compared with mRMR.

Explaining variation in the fitness of organisms is a fundamental goal in evolutionary ecology. Maintenance energy metabolism is the minimum energy required to sustain biological processes at rest (resting metabolic rate: RMR) and is proposed to drive or constrain fitness of animals; however, this remains debated. Hypotheses have been proposed as to why fitness might increase with RMR (the ‘increased intake’ or ‘performance’ hypothesis), decrease with RMR (the ‘compensation’ or ‘allocation’ hypothesis), or vary among species and environmental contexts (the ‘context dependent’ hypothesis). Here, we conduct a systematic review and meta-analysis of the literature, finding 114 studies with 355 relationships between RMR and traits that may be related to fitness. We show that individuals with relatively high RMR generally have high fitness overall, which might be supported by an increased energy intake. However, fitness proxies are not interchangeable: the nature of the RMR–fitness relationship varied substantially depending on the specific trait in question, and we found no consistent relationship between RMR and those traits most closely linked with actual fitness (i.e., lifetime reproductive success). We hypothesise that maintaining high RMR is not costly when resources are unlimited, and we propose ideas for future studies to identify mechanisms underlying RMR–fitness relationships.

PurposeMetabolic syndrome is a condition with clustering of risk factors like insulin resistance, obesity, dyslipidemia, and hypertension. Leptin is a protein of obese gene produced by white adipose tissue. Leptin resistance is the insensitivity of leptin in hypothalamus despite high amounts in blood causing obesity and metabolic syndrome. The study focused on the influence of a 12-week physical activity promotion program on leptin resistance in people with metabolic syndromeMethodsAfter approval from institutional ethics committee (IEC 343-2018), 18 participants (malesN= 4, femalesN=14) of age group 45.0±7.6 years with metabolic syndrome according to (NCEP ATP-III) criteria were included in the study. The participants underwent a 12-week physical activity program consisting of 150 min of moderate to vigorous activity per week as per GPAQ domains—work, transport, and recreation. The outcomes were measured at baseline and after 12 weeks.ResultsOut of 18 participants, 10 participants who completed the study were analysed. Twelve-week physical activity showed significant changes in waist circumference (p=0.047), post prandial blood glucose (p=0.0396), triglycerides (p=0.0323), body mass index (p=0.0056), subcutaneous fat (p=0.0354), and basal metabolic rate (p=0.0035). Fasting blood glucose (p=0.254), lipid profiles (total cholesterol (p=0.062)), high-density lipoprotein (p=0.367), low-density lipoprotein (p=0.641), and leptin showed insignificant change (p=0.328). Global physical activity questionnaire showed significant change (p=0.0254) suggesting changes in physical activity behaviors.ConclusionFrom present study, it is concluded that a 12-week physical activity promotion program brought marginal changes in leptin levels and has potential to modify metabolic syndrome parameters and improve physical activity.

Resting metabolic rate (RMR) is a widely used method to determine an individual's nutritional need. There are different methods of obtaining the RMR values to identify these needs. This study aimed to compare the RMR values using two different indirect calorimetry (IC) devices, bioelectrical impedance analysis (BIA), and two predictive equations in a sample of male university students. This cross-sectional study analyzed 65 male university students (aged 23.3 ± 2.8 years, body mass index 25.78 ± 3.98 kg/m2). RMR was obtained using two IC devices (VO2000® and Fitmate PRO®) and BIA (InBody 570®), and two predictive equations by Harris and Benedict (Proc Natl Acad Sci 4:370–373, 1918) and FAO/WHO/UNU (Food Agric Organ 1:103, 2001). The Bland–Altman (B&A) plot demonstrated considerable differences between the two gold standard methods, VO2000® and Fitmate PRO®, and BIA, with a mean difference of 7.8 and 5.7%, respectively. The B&A plot presented the lowest difference between the two IC devices with a mean difference of 2.1%. The B&A plot also showed a low difference between the two IC devices and predictive equations, with values ranging from −1.3 to −3.6%. In turn, the B&A plot between BIA and the predictive equations comprised approximately − 9.2% of the mean difference. The analysis of variance (ANOVA) demonstrated no significant differences between the measurements (p > 0.05). Based on the results, InBody 570® underestimates the reference values for RMR in two different IC devices as well as in the predictive equations. Although no significant differences were observed between ANOVA comparisons, the RMR values obtained using BIA should be analyzed with caution. The absence of sophisticated devices for RMR analysis indicates the need to use the FAO/WHO/UNU (Food Agric Organ 1:103, 2001) equation, which presented a lower difference compared with that of the gold standard measurements in male university students.

Every 10 years, an adult’s basal metabolic rate (BMR), independent of their BMI, decreases 1–2% due to skeletal muscle loss, thus decreasing an adult’s energy requirement and promoting obesity. Increased obesity augments the risk of developing Metabolic Syndrome (MetS); however, an adult’s healthy lifestyle, which increases BMR, can mitigate MetS development. To compare different BMRs for certain ages, Metabolic age (Met-age) was developed. To assess the association between Met-age and MetS and to determine if Met-age is an indicator of high-risk individuals for MetS. Four hundred thirty-five attendees at 2 clinics agreed to participate and gave signed informed consent. MetS risk was assessed by the ESF-I questionnaire. Met-age was determined using a TANITA bio-analyzer. Strengthen of association was determined by calculating Spearman’s rho and predictability was evaluated by the area-under-a-receiver-operating characteristic curve (AUC). Difference-in-age (DIA) = [chronological age − Met-age]. There was a difference between the low-risk (n = 155) and the high-risk (n = 280) groups’ Met-age (37.8±16.7 v. 62.9±17.3) and DIA (1.3±17.4 v. − 10.5±20.8, p