Search

Background & aims: Previous studies have observed changes in fat and fat-free mass among preterm infants when compared to term-born infants. However, these studies have mainly focused on moderate or very preterm infants, with a scope limited to the first few years of life. We aimed to compare body composition in extremely preterm infants to term-born infants in early childhood. Additionally, we investigated whether early neonatal nutrition was associated with the distribution of fat- and fat-free mass in later life. Methods: The study used dual-energy x-ray absorptiometry to evaluate the body composition of 52 children aged 6–9-years, of whom 35 were born extremely preterm and 17 were born at term and was analyzed using multivariate linear regression. Nutritional intakes of fluids, energy, and macronutrients during the first eight postnatal weeks for 26 extremely preterm infants were investigated in relation to body composition at age 6–9 years using Bayesian regression analysis and Gradient Boosting Machine. Results: Children born extremely preterm had smaller head circumference (confidence interval −8.7 to −1.7), shorter height (confidence interval −2.7 to −0.6), higher waist to height ratio (confidence interval 0.01–0.05) and lower fat-free mass (confidence interval −3.9 to −0.49), compared to children born at full-term. Children born extremely preterm had a differing response to amount of fluid and macronutrient intake for both fat mass index and fat-free mass index. A bimodal response showed high intake of fluid and macronutrients as associated with high fat mass index for some children, whereas others demonstrated an inverse association, suggesting analysis on cohort-level as problematic. Conclusions: Childhood body composition differs between extremely preterm infants and term-born infants. Extremely preterm infants display differing responses in their body composition to varying levels of fluids and macronutrient intake during the neonatal period.

Background: Variability in body mass index (BMI) (kg/m2) trajectories is associated with body composition and cardiometabolic markers in early childhood, but it is unknown how these associations track to later childhood. Objectives: We aimed to assess associations of BMI trajectories from 0 to 5 y with body composition and cardiometabolic markers at 10 y. Methods: In the Ethiopian infant anthropometry and body composition (iABC) birth cohort, we previously identified 4 distinct BMI trajectories from 0 to 5 y: stable low BMI (19.2%), normal BMI (48.8%), rapid growth to high BMI (17.9%), and slow growth to high BMI (14.1%). At 10 y, we obtained data from 320 children on anthropometry, body composition, abdominal subcutaneous and visceral fat, and cardiometabolic markers. Associations of BMI trajectories and 10-y outcomes were analyzed using multiple linear regression. Results: Compared with children with the normal BMI trajectory, those with rapid growth to high BMI had 1.7 cm (95% CI: 0.1, 3.3) larger waist circumference and those with slow growth to high had 0.63 kg/m2 (95% CI: 0.09, 1.17) greater fat mass index and 0.19 cm (95% CI: 0.02, 0.37) greater abdominal subcutaneous fat, whereas those with stable low BMI had −0.28 kg/m2 (95% CI: −0.59, 0.03) lower fat-free mass at 10 y. Although the confidence bands were wide and included the null value, children with rapid growth to high BMI trajectory had 48.6% (95% CI: −1.4, 123.8) higher C-peptide concentration and those with slow growth to high BMI had 29.8% (95% CI: −0.8, 69.8) higher insulin and 30.3% (95% CI: −1.1, 71.6) higher homeostasis model assessment of insulin resistance, whereas those with rapid growth to high BMI had −0.23 mmol/L (95% CI: −0.47, 0.02) lower total cholesterol concentration. The trajectories were not associated with abdominal visceral fat, blood pressure, glucose, and other lipids at 10 y. Conclusions: Children with rapid and slow growth to high BMI traject

Background and aims: Physiologic and metabolic changes following spinal cord injury (SCI) lead to an increased risk of malnutrition. The Global Leadership Initiative on Malnutrition (GLIM) is a three-step approach to diagnose malnutrition: 1) screening; 2) phenotypic and etiological criteria; and 3) malnutrition severity. The main aim of this study was to assess malnutrition in patients with SCI, according to the GLIM criteria. Methods: Patients with SCI (≥ 18 years) admitted to rehabilitation were included. Anthropometrics, food intake, and inflammation were assessed on admission. Fat-free mass index (FFMI) was estimated from bioimpedance analysis. Malnutrition was diagnosed by the GLIM criteria, using the Malnutrition Universal Screening Tool (MUST) as the first step screening tool. Sensitivity and specificity analyses were performed. Results: In total, 66 patients were assessed (50 men) with a mean age of 51.4 (± 17.4) years and median time since injury was 37.5 (10–450) days. The mean body mass index was 24.7 (± 4.2) kg/m2, and 1-month involuntary weight loss was 5.7 (± 4.4)%. FFMI for men was 17.3 (± 1.9) and for women 15.3 (± 1.6) kg/m2. Forty-one patients (62%) were malnourished according to the GLIM criteria: 27 moderately and 14 severely malnourished. MUST was not able to detect malnutrition risk of nine patients, giving a moderate agreement (kappa 0.66), with a sensitivity of 0.78 and a specificity of 0.92 compared to the GLIM diagnosis. Conclusions: In this cross-sectional study, 62% of subacute SCI patients were malnourished according to the GLIM criteria. The screening tool MUST showed moderate agreement with the GLIM criteria and did not detect risk of all patients with a malnutrition diagnosis. The clinical implications of these findings need further investigation., Background and aims: Physiologic and metabolic changes following spinal cord injury (SCI) lead to an increased risk of malnutrition. The Global Leadership Initiative on Malnutrition (GLIM) is a three-step approach to diag-nose malnutrition: 1) screening; 2) phenotypic and etiological criteria; and 3) malnutrition severity. The main aim of this study was to assess malnutrition in patients with SCI, according to the GLIM criteria. Methods: Patients with SCI (≥ 18 years) admitted to rehabilitation were included. Anthropometrics, food intake, and inflammation were assessed on admission. Fat-free mass index (FFMI) was estimated from bio-impedance analysis. Malnutrition was diagnosed by the GLIM criteria, using the Malnutrition Universal Screening Tool (MUST) as the first step screening tool. Sensitivity and specificity analyses were performed. Results: In total, 66 patients were assessed (50 men) with a mean age of 51.4 (± 17.4) years and median time since injury was 37.5 (10–450) days. The mean body mass index was 24.7 (± 4.2) kg/m2, and 1-month involun-tary weight loss was 5.7 (± 4.4)%. FFMI for men was 17.3 (± 1.9) and for women 15.3 (± 1.6) kg/m2. Forty-one patients (62%) were malnourished according to the GLIM criteria: 27 moderately and 14 severely malnour-ished. MUST was not able to detect malnutrition risk of nine patients, giving a moderate agreement (kappa 0.66), with a sensitivity of 0.78 and a specificity of 0.92 compared to the GLIM diagnosis. Conclusions: In this cross-sectional study, 62% of subacute SCI patients were malnourished according to the GLIM criteria. The screening tool MUST showed moderate agreement with the GLIM criteria and did not detect risk of all patients with a malnutrition diagnosis. The clinical implications of these findings need further investigation.

Background: Early growth and body composition may influence risk of obesity and health in adulthood. Few studies have examined how undernutrition is associated with body composition in early life.Objective: We assessed stunting and wasting as correlates of body composition in young Kenyan children.Methods: Nested in a randomized controlled nutrition trial, this longitudinal study assessed fat and fat-free mass (FM, FFM) using deuterium dilution technique among children at age 6 and 15 months. Cross-sectional and longitudinal associations between z-score categories of length-for-age Z (LAZ) or weight-for-length Z (WLZ) and FM, FFM, fat mass index (FMI), fat-free mass index (FFMI), triceps and subscapular skinfolds were analyzed by linear mixed models.Results: Among 499 children enrolled, breastfeeding declined from 99% to 87%, stunting increased from 13% to 32% and wasting remained at 2-3% between 6 and 15 months. Compared to LAZ >0, stunted children had 1.12 (95% CI: 0.88;1.36, P <0.001) kg lower FFM at 6 months increasing to 1.59 (95% CI: 1.25;1.94, P <0.001) kg at 15 months, corresponding to differences of 18% and 17%, respectively. When analysing FFMI, the deficit in FFM tended to be less than proportional to children's height at 6 months (P ≤0.060), but not at 15 months (P >0.40). Stunting was associated with 0.28 (95% CI: 0.09;0.47, P =0.004) kg lower FM at 6 months. The difference lost significance at 15 months, and stunting was not associated with FMI at any time point. Lower WLZ was generally associated with lower FM, FFM, FMI and FFMI at 6 and 15 months. Differences in FFM, but not FM, increased with time, while FFMI differences did not change and FMI differences generally decreased with time.Conclusions: Overall, low LAZ and WHZ among young Kenyan children is associated with reduced lean tissue, which may have long-term health consequences.Trial reg

Background: BIA represents an important tool in body composition (BC) assessment, especially in low-income settings in which simple and affordable options are preferred. There is a particular need to measure BC in stunted children, in which cases population-specific BIA estimating equations are lacking. Objective: We calibrated an equation to estimate body composition from BIA using deuterium dilution (2H) as the criterion method in stunted children. Methods: We measured BC with 2H and performed BIA in stunted Ugandan children (n = 50). Multiple linear regression models were constructed to predict 2H-derived FFM from BIA-derived whole-body impedance and other relevant predictors. Model performance was expressed as adjusted R2 and RMSE. Prediction errors were also calculated. Results: Participants were aged 16-59 mo, at whom 46% were girls, and their median [IQR] height-for-age z-score (HAZ) was -2.58 [-2.92, -2.37] according to WHO growth standards. Impedance index (height2/impendance measured at 50 kHz) alone explained 89.2% variation in FFM and had an RMSE of 583 g (precision error 6.5%). The final model contained age, sex, impedance index and height-for-age z-score as predictors, and explained 94.5% variation in FFM with an RMSE of 402 g (precision error 4.5%). Conclusion: We present a BIA calibration equation for a group of stunted children with relatively low prediction error. This may help evaluate the efficacy of "nutritional supplementation in large-scale trials in the same population". J Nutr 20xx;xxx:xx.

Background: Bioelectrical impedance analysis (BIA) is commonly used to evaluate body composition as part of nutritional assessment. Current guidelines recommend performing BIA measurements in a fasting state of at least 2 h in a clinical setting and 8 h in a research setting. However, since asking patients with malnutrition or sarcopenia to fast is not desirable and literature to support the strategy in the guidelines is lacking, this study aimed to assess the impact of breakfast on BIA measurements. Methods: We performed an explorative, prospective study in healthy volunteers aged between 18 and 70 years, with a normal fluid balance and a body mass index between 18.5 and 30 kg/m2. BIA measurements were performed according to the standard operating procedure in the fasting state, and 1, 2, 3, and 4 h after ingesting a standardized breakfast meal of about 400 kcal with a 150 mL drink, using the hand-to-food single-frequency BIA (Bodystat500 ®). The Kyle formula was used to calculate the primary outcome, i.e. fat-free mass (FFM, kg). A linear mixed model was used to compare baseline values with other time points. A difference of 1 kg in FFM was considered clinically relevant. Results: Thirty-nine (85% female) volunteers were included, with a median age of 28 years (IQR 24–38). In 90% of the participants, having breakfast had no clinically relevant impact on the estimated FFM. For the group, the most pronounced mean difference, a statistically but not clinically significant higher value of 0.2 kg (0.4%), was observed after 3 h of fasting compared to baseline. No statistically significant differences were found at the other time points. Conclusion: Eating affects single-frequency BIA measurements, but differences in FFM remain below clinical relevance for most participants when using a standardized breakfast. Thus, the current study suggests performing a BIA measurement in a fasting state is not required.

Plasma levels of branched-chain amino acids (BCAA) and aromatic amino acids (AAA) are considered early metabolic markers of obesity and insulin resistance (IR). This study aimed to assess changes in plasma concentrations of BCAA/AAA and HOMA-IR2 (homeostasis model assessment of IR) after intervention-induced modifications in fat mass (FM) and fat-free mass (FFM) among French Polynesian adolescents. FM, FFM, plasma levels of BCAA and AAA, HOMA-IR2 were recorded at baseline and post intervention among 226 adolescents during a 5-month school-based intervention on diet and physical activity. Participants were divided into two subgroups according to their college attendance status which determined their intervention adherence: externs/half-residents (n = 157) and residents (n = 69). Four ordinal categories of body composition changes post-intervention were created for the analysis (FMgain/FFMlost < FMgain/FFMgain < FMlost/FFMlost < FMlost/FFMgain). After 5 months, changes in BCAA (p−trend < 0.001) and AAA (p−trend = 0.007) concentrations were positively associated with ordinal categories of body composition. HOMA-IR2 significantly decreased with FMlost (−0.40; 95% CI, −0.60 to −0.20) and increased with FMgain (0.23; 95% CI, 0.11 to 0.36). Our results suggest that FM loss is associated with a decrease in concentrations of obesity and IR metabolic markers which is more substantial when FM loss is accompanied with FFM gain.

Background: Body composition changes may explain the rapid increase in blood pressure (BP) in people with HIV (PWH) during the first year of antiretroviral therapy.Methods: We analyzed data from a cohort of PWH and HIV-uninfected adults from the same communities in Mwanza, Tanzania. Blood pressure (BP, mmHg) and body composition data were collected at baseline and 12 months follow-up. We used multivariable linear regression to compare BP changes in PWH and HIV-uninfected adults, and the relationship between changes in body composition and changes in BP.Results: BP data was available for 640 PWH and 299 HIV-uninfected adults. Sixty-four percent were women and the mean age was 38 years. In PWH, systolic BP (SBP) increased (114 to 118) whereas SBP decreased (125 to 123) in HIV-uninfected participants. Fat mass increased by 1.6 kilogram on average in PWH and was strongly associated with change in BP (P < 0.001). The greater increase in SBP in PWH was partly explained by the lower baseline SBP but PWH still experienced a 2.2 (95% CI: 0.3-4.2) greater increase in SBP after adjustment. Weight gain partially mediated the relationship between HIV and SBP increase in PWH; a one kilogram increase in fat mass accounted for 0.8 (95% CI: 0.6-1.1) increase in SBP.Conclusions: Weight and fat mass increase rapidly in PWH during the first 12 months of antiretroviral therapy and contribute to a rapid increase in SBP. Interventions to prevent excessive increase in fat mass are needed for PWH.

Aim: We investigated associations between newborn body composition and anthropometry and body composition at 3 years in Danish children born from obese mothers.Methods: Analyses are based on data from the observational cohort study SKOT II (SKOT; small children's diet and wellbeing (Danish)). Body composition at birth and at 3 years was assessed by Dual-energy X-ray Absorptiometry (DXA) scans and bioelectrical impedance analysis (BIA), respectively. Multiple linear regression models were applied to determine associations between newborn body composition and anthropometry and body composition at 3 years.Results: Birthweight z-score (BWZ) was positively associated with fat-free mass (FFM), height, fat-free mass index (FFMI), fat mass (FM) and fat mass index (FMI) at 3 years. Newborn FFM was positively associated with FFM, height, FFMI and FM at 3 years and positive trends were seen between newborn FM and FM and FMI at 3 years.Conclusion: We showed that infants born with a higher BWZ go on to be taller at 3 years. They also grow to be heavier, to which FM and FFM both contribute, independently of linear growth. Additionally, it seems that FFM tracks into early childhood, thus supporting intrauterine programming of later health.

Background: A large proportion of hospitalised COVID-19 patients are overweight. There is no consensus in the literature on how lean body mass (LBM) can best be estimated to adequately guide nutritional protein recommendations in hospitalised patients who are not at an ideal weight. We aim to explore which method best agrees with lean body mass as measured by bioelectric impedance (LBMBIA) in this population. Methods: LBM was calculated by five commonly used methods for 150 hospitalised COVID-19 patients previously included in the BIAC-19 study; total body weight, regression to a BMI of 22.5, regression to BMI 27.5 when BMI>30, and the equations described by Gallagher and the ESPEN ICU guideline. Error–standard plots were used to assess agreement and bias compared to LBMBIA. The actual protein provided to ICU patients during their stay was compared to targets set using LBMBIA and LBM calculated by other methods. Results: All methods to calculate LBM suffered from overestimation, underestimation, fixed- and proportional bias and wide limits of agreement compared to LBMBIA. Bias was inconsistent across sex and BMI subgroups. Twenty-eight ICU patients received a mean of 51.19 (95%-BCa CI 37.1;64.1) grams of protein daily, accumulating to a mean of 61.6% (95%-BCa CI 43.2;80.8) of TargetBIA during their ICU stay. The percentage received of the target as calculated by the LBMGallagher method for males was the only one to not differ significantly from the percentage received of TargetBIA (mean difference 1.4% (95%-BCa CI -1.3;4.6) p = 1.0). Conclusions: We could not identify a mathematical method for calculating LBM that had an acceptable agreement with LBM as derived from BIA for males and females across all BMI subgroups in our hospitalised COVID-19 population. Consequently, discrepancies when assessing the adequacy of protein provision in ICU patients were found. We strongly advise using baseline LBMBIA to guide protein dosing if possible. In the absence of BIA, using a

Altres ajuts: Acord transformatiu CRUE-CSIC, Purpose: Bariatric surgery (BS) induces a significant and sustained weight loss in patients with severe obesity (SO). Nevertheless, apart from significantly reducing body fat, fat-free mass (FFM) might also be lost. At present, there is little and controversial data in the literature regarding the impact of BS on FFM. In recent years, bioimpedance (BIA) has emerged as a reliable test to assess body composition easily to use in the daily clinical practice. On the bases, the aim of the present study is to evaluate the impact of BS on the FFM, evaluated by means of BIA. Material and Methods: This is a prospective, observational study, including consecutive patients with SO that underwent BS between February 2018 and February 2019 at our center. At baseline, 1, 6, 12, and 24 months after the BS, all the patients underwent complete medical history, physical and anthropometric evaluation, and body composition assessment by means of BIA (using Bodystat QuadScan4000®). Results: Eighty-five patients with SO were recruited, 72.9% females, aged 45.54 ± 9.98 years, pre-BS BMI 43.87 ± 6.52 kg/m. FFM significantly decreased continuously after BS at all timepoints. The loss of FFM 24 months post-BS accounted for approximately 21.71 ± 13.9% of the total weight loss, and was independent of BS technique or protein metabolism. Pre-BS HOMA-IR and FFM were independent predictors of FFM at 24 months. Conclusions: Significant and early loss of FFM in patients with SO that undergo BS was seen, not related to protein metabolism parameters or the BS technique used, suggesting an independent mechanism. Graphical abstract: [Figure not available: see fulltext.]

Considering that the prevalence of overweight and obesity in Southeast of Spain is high, the aim of this work was to analyze the relation between the adherence to a personalized diet and the effectiveness of changes in the body composition in overweight and obese adults in this region. This quasi-experimental study presents the following selection criteria: attendance at the consultation between 2006 and 2012, subjects ≥ 19 years of age with overweight or obesity. In total, 591 overweight or obese individuals were involved in this study, attending 4091 clinic consultations in total. Most of the sample consisted of subjects who attended >3 consultations (>1.5 months), and were females aged 19–64 years who obtained clinically significant changes in fat mass (FM, ≥5%) and recommended changes in fat-free mass (FFM, ≥0%). Based on the results obtained and the experience gained from this research, the following recommendations are established: (i) record fat mass and fat-free mass index as a complement to body mass index; (ii) use FM and FFM to evaluate effectiveness of interventions with the aim of obtaining body composition changes; (iii) use personalized diet to achieve significant changes in FM and avoid non-recommended changes in FFM.

Purpose: An influential covariate for pharmacokinetics is (body) size. Recently, the method of estimation of normal fat mass (NFM) has been advocated. Here, the relative contribution of fat mass, estimated as a fraction fat (Ffat), is used to explain differences in pharmacokinetic parameters. This concept is more and more applied. However, it remains unclear whether NFM can be reliably estimated in these typical studies. Methods: We performed an evaluation of the reliability of NFM estimation in a typical study size (n = 30), otherwise best-case scenario, by means of a pharmacokinetic simulation study. Several values of Ffat were investigated. Results: In a typical pharmacokinetic study, high imprecision was observed for NFM parameter estimates over a range of scenarios. For example, in a scenario where the true value of Ffat on clearance was 0.5, we found a 95% confidence interval of - 0.1 to 2.1, demonstrating a low precision. The implications for practice are that one could conclude that fat-free mass best describes the relationship of the pharmacokinetics with body size, while the true relationship was between fat-free mass and total body weight. Consequently, this could lead to incorrect extrapolation of pharmacokinetics to extreme body sizes. Conclusion: In typical pharmacokinetic studies, NFM should be used with caution because the Ffat estimates have low precision. The estimation of Ffat should always be preceded by careful study design evaluation before planning a study, to ensure that the design and sample size is sufficient to apply this potentially useful methodology.

Background & aims: The European Food Safety Authority recently recommended an increase in the protein content of total diet replacement (TDR) products from 50 to 75 g/day. The rationale was to minimize reductions in lean mass (LM) and resting metabolic rate (RMR) that occur with weight loss, and thereby facilitate maintenance of lost weight. We sought to directly compare the efficacy of TDR regimens with the new vs the current protein requirement.Methods: We randomized 108 adults with overweight or obesity (body mass index 28-40 kg/m2) to very-low-calorie diets (VLCD) with either 52 or 77 g/day protein for 8 weeks (total energy intake of 600 or 700 kcal/day, respectively). LM was determined by dual energy X-ray absorptiometry and RMR by indirect calorimetry.Results: Attrition rate was 22% in both groups. Both VLCDs decreased body weight, fat mass, LM, and RMR (all P < 0.05). Significant time-by-group interactions were detected for weight and fat mass (both P < 0.05), with corresponding reductions being smaller in the higher-protein than the standard-protein VLCD, likely because of the added calories. On the other hand, reductions in LM (6% from baseline) and RMR (9-10% from baseline) did not differ between groups (P = 0.155 and P = 0.389, respectively), and the contribution of LM to total weight loss was identical (27 ± 2% of lost weight, P = 0.973).Conclusions: Our results indicate that the proposed increase in the protein content of TDR products does not attenuate reductions in LM and RMR in individuals with overweight and obesity who are treated with <800 kcal/day VLCDs for 2 months.Clinical trial registry: ClinicalTrials.gov # NCT04156165.

Background: The current severe acute respiratory syndrome coronavirus 2 pandemic is unprecedented in its impact. It is essential to shed light on patient characteristics that predispose to a more severe disease course. Obesity, defined as a BMI>30 kg/m2, is suggested to be one of these characteristics. However, BMI does not differentiate between fat mass and lean body mass, or the distribution of fat tissue. The aim of the present study was to assess the body composition of COVID-19 patients admitted to the ward or the ICU and identify any associations with severity of disease. Methods: We performed an observational cross-sectional cohort study. Bioelectric impedance analysis was conducted amongst all confirmed COVID-19 patients admitted to the ward or ICU of our hospital in the Netherlands, between April 10 and 17, 2020. Body water measurements and derived values were recalculated to dry weight, using a standard ratio of extracellular water to total body water of 0.38. Data were compared between the ward and ICU patients, and regression models were used to assess the associations between baseline characteristics, body composition, and several indicators of disease severity, including a composite score composed of mortality, morbidity, and ICU admission. Results: Fifty-four patients were included, of which 30 in the ward and 24 in the ICU. The mean age was 67 years (95%-CI 64–71), and 34 (63%) were male. Mean BMI was 29.7 (95%-CI 28.2–31.1) kg/m2 and did not differ between groups. Body composition values were not independently associated with disease severity. In multiple logistic regression analyses, a low phase angle was associated with COVID-19 severity in the composite score (OR 0.299, p = 0.046). Conclusion: We found no significant associations between body composition, including fat mass, visceral fat area, and fat-free mass, and disease severity in our population of generally overweight COVID-19 patients. A lower phase angle did increase the odds of severe CO

We meta-analyze amyotrophic lateral sclerosis (ALS) genome-wide association study (GWAS) data of European and Chinese populations (84,694 individuals). We find an additional significant association between rs58854276 spanning ACSL5-ZDHHC6 with ALS (p = 8.3 × 10−9), with replication in an independent Australian cohort (1,502 individuals; p = 0.037). Moreover, B4GALNT1, G2E3-SCFD1, and TRIP11-ATXN3 are identified using a gene-based analysis. ACSL5 has been associated with rapid weight loss, as has another ALS-associated gene, GPX3. Weight loss is frequent in ALS patients and is associated with shorter survival. We investigate the effect of the ACSL5 and GPX3 single-nucleotide polymorphisms (SNPs), using longitudinal body composition and weight data of 77 patients and 77 controls. In patients’ fat-free mass, although not significant, we observe an effect in the expected direction (rs58854276: −2.1 ± 1.3 kg/A allele, p = 0.053; rs3828599: −1.0 ± 1.3 kg/A allele, p = 0.22). No effect was observed in controls. Our findings support the increasing interest in lipid metabolism in ALS and link the disease genetics to weight loss in patients.

Postprint (author's final draft)

Understanding the mechanisms of hunger, satiety and how nutrients affect appetite control is important for successful weight management across the lifecourse. The primary aim of this study was to describe acute appetite control across the lifecourse, comparing age groups (children, adolescents, adults, elderly), weight categories, genders and European sites (Scotland and Greece). Participants (n = 391) consumed four test drinks, varying in composition (15% (normal protein, NP) and 30% (high protein, HP) of energy from protein) and quantity (based on 100% basal metabolic rate (BMR) and 140% BMR), on four separate days in a double-blind randomized controlled study. Ad libitum energy intake (EI), subjective appetite and biomarkers of appetite and metabolism (adults and elderly only) were measured. The adults' appetite was significantly greater than that of the elderly across all drink types (p <0.004) and in response to drink quantities (p <0.001). There were no significant differences in EI between age groups, weight categories, genders or sites. Concentrations of glucagon-like peptide 1 (GLP-1) and peptide YY (PYY) were significantly greater in the elderly than the adults (p <0.001). Ghrelin and fasting leptin concentrations differed significantly between weight categories, genders and sites (p <0.05), while GLP-1 and PYY concentrations differed significantly between genders only (p <0.05). Compared to NP drinks, HP drinks significantly increased postprandial GLP-1 and PYY (p <0.001). Advanced age was concomitant with reduced appetite and elevated anorectic hormone release, which may contribute to the development of malnutrition. In addition, appetite hormone concentrations differed between weight categories, genders and geographical locations.

Hintergrund und Ziel Eine Gewichtsreduktion im Alter birgt das Risiko, eine durch die altersabhängige Reduktion der fettfreien Masse (FFM) bedingte Sarkopenie noch zusätzlich zu erhöhen. Aufgrund des Zusammenhangs zwischen FFM und Ruheenergieumsatz (REE) ist es ebenfalls notwendig eine Reduktion dessen zu vermeiden. Zudem ist es von besonderer Bedeutung, die physische Funktion (PF) der Betroffenen zu erhalten. Ziel der Studie war deshalb zu prüfen, ob durch eine Reduktionsdiät mit erhöhter Proteinzufuhr die FFM, der REE und die PF besser erhalten bleiben als bei einer Diät mit normaler Proteinzufuhr. Methoden In einer zwölfwöchigen Interventionsphase mit einer Reduktion des individuellen Gesamtenergiebedarfs von 750 kcal/d wurden 54 postmenopausale Frauen (BMI 30,9 ± 3,4 kg/m²; 59 ± 7 Jahre) in die Gruppen mit 0,8 g Protein/kg Körpergewicht (KG)/d (Gruppe K) bzw. 1,5 g/kg KG/d (Gruppe P) doppelt verblindet randomisiert. Die Proteindosis wurde gleichmäßig auf zwei Trinkmahlzeiten und eine feste Mahlzeit verteilt. Die Shakes der P-Gruppe wurden zusätzlich mit reinem Molkeneiweiß angereichert. Begleitend wurden in vier Schulungen Informationen bezüglich des Ablaufes der Studie und insbesondere zu gesunder Ernährung vermittelt. Die Probandinnen führten jeweils zu Beginn und am Ende des Interventionszeitraums ein 7-Tage Ernährungsprotokoll. Die Parameter FFM (mittels bioelektrischer Impedanzanalyse), REE (mittels indirekter Kalorimetrie), PF (Kraft, Ausdauer, Balance mittels short shysical performance battery SPPB, 400 m Gehgeschwindigkeit und Handkraft mittels Handdynamometer), Blutparameter (Lipid- und Kohlenhydratprofil, Harnstoff, Vitamin D, Calcium, Magnesium, Leber- und Nierenwerte aus dem Serum) und Blutdruck wurden vor der Intervention (t0), nach der Intervention (t1) und nach einer Follow-Up Phase von sechs Monaten (t2) erhoben. Die Auswertung erfolgte primär als Intention to treat Analyse mit Korrelations- und Regressionsanalysen, gepaarten und ungepaarten t-Te, Aim Weight loss in old age increases the risk of sarcopenia caused by the age-related reduction of fat-free mass (FFM). Due to the strong correlation between FFM and resting energy expenditure (REE), the maintenance of this must also be considered. In addition, the physical function (PF) must be maintained. The objective was to investigate the impact of protein intake on changes in fat-free mass (FFM), resting energy expenditure (REE), and physical function (PF) during weight loss. Methods 54 postmenopausal women (BMI 30.9 ± 3.4 kg/m²; 59 ± 7 years of age) were randomized into two groups with 0.8 g (K) or 1.5 g protein/kg body weight/d (P) energy-restricted diets (- 750 kcal of individual energy requirements) for 12 weeks, followed by six months weight maintenance with ad libitum food intake. The protein dose was evenly distributed to two liquid and one solid meal. The shakes of the P group were additionally enriched with pure whey protein. Four seminars were held to provide information on the course of the study and in particular on healthy nutrition. At the beginning and at the end of the study, the subjects kept a 7-day nutrition protocol. FFM (by bioelectrical impedance analysis), REE (by indirect calorimetry), PF (strength, endurance, and balance by short physical performance battery test (SPPB), 400 m walking speed and handgrip strength by hand dynamometer), blood parameters (lipid and carbohydrate profile, urea, vitamin D, calcium, magnesium, liver and kidney values from serum) and blood pressure were measured at baseline, after weight loss, and after follow up. The evaluation was primarily based on an intention to treat analysis with correlation and regression analysis, paired and unpaired t-tests, whereby the significance level was set ≤ at 0.05. The values given are continuous mean values ± standard deviation. Results 46 women completed the weight loss intervention and 29 were followed up after weight maintenance. Weight loss was -4.6 ± 3.6 kg (P) an

STUDY OBJECTIVES: The current study sought to examine whether self-reported sleep duration is linked to an adverse body composition in 19,709 adults aged 45 to 75 years. METHODS: All variables used in the current study were derived from the Swedish EpiHealth cohort study. Habitual sleep duration was measured by questionnaires. Body composition was assessed by bioimpedance. The main outcome variables were fat mass and fat-free mass (in kg). Analysis of covariance adjusting for age, sex, fat mass in the case of fat-free mass (and vice versa), leisure time physical activity, smoking, and alcohol consumption was used to investigate the association between sleep duration and body composition. RESULTS: Short sleep (defined as ≤ 5 hours sleep per day) and long sleep (defined as 8 or more hours of sleep per day) were associated with lower fat-free mass and higher fat mass, compared with 6 to 7 hours of sleep duration (P< .05). CONCLUSIONS: These observations could suggest that both habitual short and long sleep may contribute to two common clinical phenotypes in middle-aged and older humans, ie, body adiposity and sarcopenia. However, the observational nature of our study does not allow for causal interpretation.

Aims Increases in fat-free mass and fat mass have been associated with higher risk of atrial fibrillation (AF) in observational studies. It is not known whether these associations reflect independent causal processes. Our aim was to evaluate independent causal roles of fat-free mass and fat mass on AF. Methods and results We conducted a large observational study to estimate the associations between fat-free mass and fat mass on incident AF in the UK Biobank (N = 487 404, N events = 10 365). Genome-wide association analysis was performed to obtain genetic instruments for Mendelian randomization (MR). We evaluated the causal effects of fat-free mass and fat mass on AF with two-sample method by using genetic associations from AFGen consortium as outcome. Finally, we evaluated independent causal effects of fat-free mass and fat mass with multivariate MR. Both fat-free mass and fat mass had observational associations with incident AF [hazard ratio (HR) = 1.77, 95% confidence interval (CI) 1.72-1.83; HR = 1.40, 95% CI 1.37-1.43 per standard deviation increase in fat-free and fat mass, respectively]. The causal effects using the inverse-variance weighted method were 1.55 (95% CI 1.38-1.75) for fat-free mass and 1.30 (95% CI 1.17-1.45) for fat mass. Weighted median, Egger regression, and penalized methods showed similar estimates. The multivariate MR analysis suggested that the causal effects of fat-free and fat mass were independent of each other (causal risk ratios: 1.37, 95% CI 1.06-1.75; 1.28, 95% CI 1.03-1.58). Conclusion Genetically programmed increases in fat-free mass and fat mass independently cause an increased risk of AF.

Obesity is associated with increased morbidity and mortality. A BMI >40 kg/m2 shortens life expectancy by about 10 years. The obesity related comorbidities diabetes, hypertension, dyslipidemia and sleep apnea contributes to the increased risk of cardiovascular events. There is also an increased risk of some forms of cancer (e.g. colon, breast, and prostate cancer) as well as mental illness (depression and low self-esteem). Bariatric surgery is indicated for those with a BMI >35 kg/m2. Unfortunately, there are an increasing number of patients seeking bariatric surgery who are super obese (BMI >50 kg/m2), a condition more difficult to treat because of insufficient weight loss with standard operations, like the Roux-en-Y Gastric Bypass (RYGB). Therefore some surgeons advocate the Duodenal Switch (DS) in super obese patients, because DS results in greater and more sustained weight loss. However, DS is a technically more challenging operation and is associated with an increased risk of malnutrition and surgical complications. There are also concerns about an excessive loss of fat-free mass during weight loss after RYGB and especially after DS. This thesis focuses on weight-loss, effect on comorbidities, quality of life and complications after DS and RYGB, respectively, with comparisons between the two procedures in patients with super obesity. DS resulted in a superior weight loss compared to RYGB (paper I, II and III) and body composition after weight loss did not differ compared with non-operated controls with the same BMI after surgery, for neither DS nor RYGB (paper I). Both DS and RYGB resulted in an improved metabolic control (paper II and III), but the effect on diabetes and hypertension was greater and maintained in the long-term after DS (paper III). Both DS and RYGB resulted in an improved physical quality of life, with greater improvements after DS (paper III). However, complications and long-term adverse effects were more common after DS (paper II a

Background: A detrimental consequence of diet-induced weight loss, common in athletes who participate in weight cutting sports, is muscle loss. Dietary omega-3 polyunsaturated fatty acids (n-3PUFA) exhibit a protective effect on the loss of muscle tissue during catabolic situations such as injury-simulated leg immobilization. This study aimed to investigate the influence of dietary n-3PUFA supplementation on changes in body composition and muscle strength following short-term diet-induced weight loss in resistance-trained men. Methods: Twenty resistance-trained young (23 ± 1 years) men were randomly assigned to a fish oil group that supplemented their diet with 4 g n-3PUFA, 18 g carbohydrate, and 5 g protein (FO) or placebo group containing an equivalent carbohydrate and protein content (CON) over a 6 week period. During weeks 1–3, participants continued their habitual diet. During week 4, participants received all food items to control energy balance and a macronutrient composition of 50% carbohydrate, 35% fat, and 15% protein. During weeks 5 and 6, participants were fed an energy-restricted diet equivalent to 60% habitual energy intake. Body composition and strength were measured during weeks 1, 4, and 6. Results: The decline in total body mass (FO = −3.0 ± 0.3 kg, CON = −2.6 ± 0.3 kg), fat free mass (FO = −1.4 ± 0.3 kg, CON = −1.2 ± 0.3 kg) and fat mass (FO = −1.4 ± 0.2 kg, CON = −1.3 ± 0.3 kg) following energy restriction was similar between groups (all p > 0.05; d: 0.16–0.39). Non-dominant leg extension 1 RM increased (6.1 ± 3.4%) following energy restriction in FO (p < 0.05, d = 0.29), with no changes observed in CON (p > 0.05, d = 0.05). Dominant leg extension 1 RM tended to increase following energy restriction in FO (p = 0.09, d = 0.29), with no changes in CON (p > 0.05, d = 0.06). Changes in leg press 1 RM, maximum voluntary contraction and m

Background: Large cohort longitudinal studies have almost unanimously concluded that metabolic health in obesity is a transient phenomenon, diminishing in older age. We aimed to assess the fate of insulin sensitivity per se over time in overweight and obese individuals. Methods: Individuals studied using the hyperinsulinaemic-euglycaemic clamp at the Garvan Institute of Medical Research from 2008 to 2010 (n = 99) were retrospectively grouped into Lean (body mass index (BMI) < 25 kg/m2) or overweight/obese (BMI ≥ 25 kg/m2), with the latter further divided into insulin-sensitive (ObSen) or insulin-resistant (ObRes), based on median clamp M-value (M/I, separate cut-offs for men and women). Fifty-seven individuals participated in a follow-up study after 5.4 ± 0.1 years. Hyperinsulinaemic-euglycaemic clamp, dual-energy X-ray absorptiometry and circulating cardiovascular markers were measured again at follow-up, using the same protocols used at baseline. Liver fat was measured using computed tomography at baseline and proton magnetic resonance spectroscopy at follow-up with established cut-offs applied for defining fatty liver. Results: In the whole cohort, M/I did not change over time (p = 0.40); it remained significantly higher at follow-up in ObSen compared with ObRes (p = 0.02), and was not different between ObSen and Lean (p = 0.41). While BMI did not change over time (p = 0.24), android and visceral fat increased significantly in this cohort (ptime ≤ 0.0013), driven by ObRes (p = 0.0087 and p = 0.0001, respectively). Similarly, systolic blood pressure increased significantly over time (ptime = 0.0003) driven by ObRes (p = 0.0039). The best correlate of follow-up M/I was baseline M/I (Spearman’s r = 0.76, p = 1.1 × 10-7). Conclusions: The similarity in insulin sensitivity between the ObSen and the Lean groups at baseline persisted over time. Insulin resistance in overweight and obese individuals predisposed to further metabolic deterioration over time.

There is evidence to indicate that the central biological clock (i.e., our endogenous circadian system) plays a role in physiological processes in the body that impact energy regulation and metabolism. Cross-sectional data suggest that energy consumption later in the day and during the night is associated with weight gain. These findings have led to speculation that when, as well as what, we eat may be important for maintaining energy balance. Emerging literature suggests that prioritising energy intake to earlier during the day may help with body weight maintenance. Evidence from tightly controlled acute experimental studies indicates a disparity in the body’s ability to utilise (expend) energy equally across the day and night. Energy expenditure both at rest (resting metabolic rate) and after eating (thermic effect of food) is typically more efficient earlier during the day. In this review, we discuss the key evidence for a circadian pattern in energy utilisation and balance, which depends on meal timing. Whilst there is limited evidence that simply prioritising energy intake to earlier in the day is an effective strategy for weight loss, we highlight the potential benefits of considering the role of meal timing for improving metabolic health and energy balance. This review demonstrates that to advance our understanding of the contribution of the endogenous circadian system toward energy balance, targeted studies that utilise appropriate methodologies are required that focus on meal timing and frequency

The study aimed at assessing stunting and wasting as correlates of body composition in Cambodian children. As part of a nutrition trial (ISRCTN19918531), fat (FM) and fat-free mass (FFM) were measured using 2H dilution at 6 and 15 months of age. Linear mixed-effects models were used to assess associations of stunting, wasting, sex and breastfeeding with FM and FFM and height-adjusted indexes FMI and FFMI. Of 419 infants enrolled, 98% were breastfed, 15% stunted and 4% wasted at 6 months. At 15 months, 78% were breastfed, 24% stunted and 11% wasted. Those not breastfed had lower FMI at 6 months (-1.22; 95% CI -2.05;-0.39) but not at 15 months (-0.23, -0.51;0.051). Stunted children had lower FM at 6 months and lower FFM at 6 and 15 months compared to children with length-for-age ≥0 Z. Stunting was not associated with FMI or FFMI. Wasted children had lower FM, FFM, FMI and FFMI at 6 and 15 months compared to children with weight-for-length z (WLZ) ≥0. Generally, FFM and FFMI deficits increased with age, whereas FM and FMI deficits decreased, reflecting interactions between age and WLZ. For example, the FFM deficits were -0.99 (-1.26;-0.72) kg at 6 months, and -1.44 (-1.69; -1.19) kg at 15 months (interaction, p<0.05), while the FMI deficits were -2.12 (-2.53;-1.72) kg/m2 at 6 months and -1.32 (-1.77;-0.87) kg/m2 at 15 months (interaction, P<0.05). This indicates that undernourished children preserve body fat at the detriment of fat-free tissue, which may have long-term consequences for health and working capacity.

Estrogen-based hormone replacement therapy (HRT) may be associated with deceleration of cellular aging. We investigated whether long-term HRT has effects on leukocyte (LTL) or mean and minimum skeletal muscle telomere length (SMTL) in a design that controls for genotype and childhood environment. Associations between telomeres, body composition, and physical performance were also examined. Eleven monozygotic twin pairs (age 57.6 ± 1.8 years) discordant for HRT were studied. Mean duration of HRT use was 7.3 ± 3.7 years in the user sister, while their co-twins had never used HRT. LTL was measured by qPCR and SMTLs by southern blot. Body and muscle composition were estimated by bioimpedance and computed tomography, respectively. Physical performance was measured by jumping height and grip strength. HRT users and non-users did not differ in LTL or mean or minimum SMTL. Within-pair correlations were high in LTL (r = 0.69, p = .020) and in mean (r = 0.74, p = .014) and minimum SMTL (r = 0.88, p = .001). Body composition and performance were better in users than non-users. In analyses of individuals, LTL was associated with BMI (r 2 = 0.30, p = .030), percentage total body (r 2 = 0.43, p = .014), and thigh (r 2 = 0.55, p = .004) fat, while minimum SMTL was associated with fat-free mass (r 2 = 0.27, p = .020) and thigh muscle area (r 2 = 0.42, p = .016). We found no associations between HRT use and telomere length. Longer LTLs were associated with lower total and regional fat, while longer minimum SMTLs were associated with higher fat-free mass and greater thigh muscle area. This suggests that telomeres measured from different tissues may have different associations with measures of body composition., Funding Agencies:EC FP7 Collaborative Project MYOAGE GA-223576Academy of Finland 265240 263278Finnish Ministry of Culture and Education 251316 89/672/2008Post doc research grant from the Academy of Finland 260001

Introduction Secondary functional hypothalamic amenorrhea (SFHA) is common among female athletes, especially in weight-sensitive sports. The aim of this study was to investigate the link between SFHA and neuromuscular performance in elite endurance athletes. Methods Sixteen eumenorrheic (EUM) and 14 SFHA athletes from national teams and competitive clubs participated. Methods included gynecological examination, body composition (dual-energy x-ray absorptiometry), resting metabolic rate and work efficiency, exercise capacity, knee muscular strength (KMS) and knee muscular endurance (KME), reaction time (RT), blood sampling performed on the third to fifth days of the menstrual cycle, and 7-d assessment of energy availability. Results SFHA athletes had lower estrogen (0.12 0.03 vs 0.17 +/- 0.09 nmolL(-1), P < 0.05), triiodothyronine (T-3) (1.4 +/- 0.2 vs 1.7 +/- 0.3 nmolL(-1), P < 0.01), and blood glucose (3.8 +/- 0.3 vs 4.4 +/- 0.3 mmolL(-1), P < 0.001) but higher cortisol levels (564 +/- 111 vs 400 +/- 140 nmolL(-1), P < 0.05) compared with EUM athletes. SFHA had a lower body weight (55.0 +/- 5.8 vs 60.6 +/- 7.1 kg, P < 0.05), but no difference in exercise capacity between groups was found (56.4 +/- 5.8 vs 54.0 +/- 6.3 mL O(2)min(-1)kg(-1)). RT was 7% longer, and KMS and KME were 11% and 20% lower compared with EUM athletes. RT was negatively associated with glucose (r = -0.40, P < 0.05), T-3 (r = -0.37, P < 0.05), and estrogen (r = -0.43, P < 0.05), but positively associated with cortisol (r = 0.38, P < 0.05). KMS and KME correlated with fat-free mass in the tested leg (FFMleg; r = 0.52, P < 0.001; r = 0.58, P < 0.001) but were negatively associated with cortisol (r = -0.42, P < 0.05; r = -0.59, P < 0.001). FFMleg explained the differences in KMS, while reproductive function and FFMleg independently explained the variability in KME. Conclusions We found lower neuromuscular performance among SFHA compared with EUM athletes linke

BACKGROUND: Clinical practice guidelines globally recommend lifestyle modification including diet and exercise training as first-line treatment for obesity. The clinical benefits of exercise training in adults with obesity is well-documented; however, there is no strong evidence for the effectiveness of exercise training for weight loss in class II and class III obesity. The purpose of the randomised controlled trial described in this protocol article is to examine the effect of exercise training, in addition to a very low energy diet (VLED), in clinically severe obese women for changes in body composition, physical function, quality of life, and markers of cardiometabolic risk. METHODS/DESIGN: Sixty women, aged 18-50 years with a body mass index (BMI) greater than 34.9 kg.m(2) and at least one obesity-related co-morbidity, will be recruited for this 12-month study. Participants will be randomised to either exercise plus energy restriction (n = 30), or energy restriction alone (n = 30). All participants will follow an energy-restricted individualised diet incorporating a VLED component. The exercise intervention group will also receive exercise by supervised aerobic and resistance training and a home-based exercise programme totalling 300 minutes per week. Primary outcome measures include body composition and aerobic fitness. Secondary outcome measures include: physical function, cardiometabolic risk factors, quality of life, physical activity, and mental health. All outcome measures will be conducted at baseline, 3, 6 and 12 months. DISCUSSION: Previous research demonstrates various health benefits of including exercise training as part of a healthy lifestyle at all BMI ranges. Although clinical practice guidelines recommend exercise training as part of first-line treatment for overweight and obesity, there are few studies that demonstrate the effectiveness of exercise in class II and class III obesity. The study aims to determine whether th

Background: Changes in body composition in cancer patients during chemotherapy are associated with treatment related toxicities or mortalities. Thus, it is relevant to identify accessible, relatively inexpensive, portable and reliable tools for evaluation of body composition in cancer patients during the course of their treatments. Objective: To examine relationships between single cross-sectional thighs magnetic resonance imaging (MRI), skeletal muscle mass (SM) as reference and multi-frequency bioelectrical impedance analysis (BIA) fat free mass (FFM) in patients with colorectal cancer undergoing chemotherapy. Design: In an observational, prospective study we examine the relationships between single cross-sectional thighs MRI (T1-weighted (1.5 T) SM compared to FFM BIA (8-electrodes multi-frequency Tanita MC780MA)) and FFM skin-fold thickness (ST) (4-points (Harpenden, Skinfold Caliper)) and SM equation for non-obese persons from Lee et al. 2000 (L2000) (based on age, height, weight, sex and race). FFM and SM (kg) were calculated based on either area (MRI) or weight.Results: 18 CRC patients (10 males and 8 females) with mean (SD) age 67 yr (6) were measured at baseline, and 13 were available for follow-up. BIA overestimated FFM kg for all 31 measurements with mean (SD) 18.0 kg (6.0) compared to the MRI. ST overestimated FFM kg with mean 12.4 kg (6.2) and L2000 underestimated SM kg in 18 measurements and overestimated in 13 with a total mean of −4.3 kg (6.8). Conclusions BIA and ST were the best alternatives to MRI as they showed constant and thereby correctable errors. The equation, L2000, carried the smallest average measurement error but it was non-constant.

Background Body composition (BC) analysis based on bioelectrical impedance analysis (BIA) provides conflicting results. The purpose of the study was to validate an equation specific for young patients with cystic fibrosis (CF), describe their BC and investigate its association with lung function. Methods Fifty-four young CF patients were evaluated by BIA and dual X-ray absorptiometry (DXA). An empirically derived CF-specific equation for fat-free mass (FFM) estimation by BIA was elaborated after stepwise multivariate regression and the agreement between BIA and DXA was assessed by Bland–Altman plots. The association between BC and lung function was investigated by regression analysis. Results The mean difference between the BIA and DXA assessment was close to zero. A total of 22.5% of patients (n = 9) presented a FFM z-score ≤ − 2. They had a worse pulmonary function and diaphragmatic impairment. Among these 9 patients, 7 had a normal BMI z-score > − 1. Conclusions BIA, based on a CF-specific equation, is a reliable method for BC assessment and allows the identification of patients at risk of nutritional degradation and bad respiratory prognosis., SCOPUS: ar.j, info:eu-repo/semantics/published

This study tested the hypothesis that hypoxia exacerbates reductions in body mass observed during unloading. To discern the separate and combined effects of simulated microgravity and hypoxia, 11 healthy males underwent three 21-day campaigns in a counterbalanced fashion: (1) normoxic bed rest (NBR; FiO2 = 0.209; PiO2 = 133.1 +/- A 0.3); (2) hypoxic ambulatory confinement (HAMB; FiO2 = 0.141 +/- A 0.004; PiO2 = 90.0 +/- A 0.4; similar to 4,000 m); and (3) hypoxic bed rest (HBR; FiO2 = 0.141 +/- A 0.004; PiO2 = 90.0 +/- A 0.4). The same dietary menu was applied in all campaigns. Targeted energy intakes were estimated individually using the Harris-Benedict equation taking into account whether the subjects were bedridden or ambulatory. Body mass and water balance were assessed throughout the campaigns. Whole body and regional body composition was determined before and after the campaigns using dual-energy X-ray absorptiometry. Before and during the campaigns, indirect calorimetry and visual analogue scores were employed to assess the resting energy expenditure (REE) and perceived appetite sensations, respectively. Energy intakes were lower than targeted in all campaigns (NBR: -5 %; HAMB: -14 %; HBR: -6 %; P < 0.01). Body mass significantly decreased following all campaigns (NBR: -3 %; HAMB: -4 %; HBR: -5 %; P < 0.01). While fat mass was not significantly altered, the whole body fat free mass was reduced (NBR: -4 %; HAMB: -5 %; HBR: -5 %; P < 0.01), secondary to lower limb fat-free mass reduction. Water balance was comparable between the campaigns. No changes were observed in REE and perceived appetite. Exposure to simulated altitude of similar to 4,000 m does not seem to worsen the whole body mass and fat-free mass reductions or alter resting energy expenditure and appetite during a 21-day simulated microgravity., QC 20141205

Sojourns at high altitude are often accompanied by weight loss and changes in body composition. The aim was to study body composition before and after 40 days high-altitude exposure. The subjects were four women and six men, non-smoking, healthy and active students and a scientist from Mid Sweden University in Östersund with a mean (SD) age of 26 (10) years. All subjects volunteered for a six-week trek to the Mount Everest Base Camp via Rolwaling in Nepal. Before the sojourn subject’s height was 177 (10) cm and weight was 71.9 (10) kg. Body composition was measured with Lunar iDXA at the Swedish Winter Sports Research Centre in Östersund before and after the trek. Total body mass (SD) decreased from 71.8 (10.0) kg before to 69.7 (9.4) kg after the trek (P=0.00). Total fat mass decreased from 14.7 (5.9) kg to 13.8 (4.6) kg (P=0.01). Fat percent decreased from 21.6 (7.9) % to 21.0 (7.2) % (P=0.03). Total lean mass decreased from 54.0 (10.0) kg to 52.9 (9.7) kg (P=0.01). Bone mineral content was unchanged, 3.04 (0.5) kg before and 3.03 (0.5) after (P=0.13). Thus both total body mass and total lean mass had decreased after a six week trekking in Nepal.

Background: This study retrospectively investigated nutritional status, dietetic intervention and intake in Cystic Fibrosis (CF) patients before and after lung transplantation (LTX). Methods: Body Mass Index (BMI), Fat Free Mass Index (FFMI) and nutritional intake were retrieved from 75 out-patients aged 15-53 years. Patients were seen every 3-4 months during the waiting list time (range 0-81 months) and up to 116 months after LTX. Survival was measured in months. Results: The median BMI at baseline was 19.2 kg/m(2) (range: 15.3 to 28.4 kg/m(2)) with 29 patients (39%) below = 500 kcal less than recommended. Protein intake was 104 (range 60-187) g or 1.9 g/kg per day. Despite dietetic intervention with oral nutritional supplements (ONS) (36 patients), tube feeding (12 patients), or both (13 patients), HMI and FFMI hardly improved pre-LTX. LTX was performed in 51 patients (68%); 10 patients died during follow-up, median survival time was 41 months. A BMI 18.5 kg/m(2) was more prevalent in patients who died before LTX (6/9) or who died after LTX (4/10) than in patients who were still alive on the waiting list (5/15) or who survived LTX (14/41). Results for FFMI were comparable. From 6-12 months post-LTX, BMI and FFMI markedly improved, especially in underweight patients. Conclusion: A BMI

In this paper, we present a framework to analyze the propagation of measurement errors through the body composition equations. This is done through the equations for body composition assessment (BCA), for single/multifrequency (SF, MF) body impedance analysis (BIA) approaches. We show that it is possible to estimate a priori the error variance on the BCA parameters from the error measurement in the weight, height, and impedance. The theoretical results are validated through the simulation and experimental data coming from the low-cost AFE4300 impedance spectrometer developed by Texas Instruments. This new spectrometer has been calibrated and characterized by performing measurements on phantoms and foot-to-foot body impedance measurements. The influence of the number of measurement frequencies on the accuracy of BCA is also studied for MF-BIA approach. Ultimately, the measurement error framework can be used to evaluate the suitability of an impedance system for BIA., Peer Reviewed, Postprint (published version)

Postmenopausal women experience an age-related decline in resting energy expenditure (REE), which is a risk factor for energy imbalance and metabolic disease. Exercise, because of its association with greater lean tissue mass and other factors, has the potential to mediate REE decline, but the relation between exercise and REE in postmenopausal women is not well characterized. This study tests the hypothesis that exercise energy expenditure (EEE) is positively associated with REE and can counter the effects of age and menopause. It involves a cross-sectional sample of 31 healthy postmenopausal women (aged 49-72 years) with habitual exercise volumes at or above levels consistent with current clinical recommendations. Subjects kept exercise diaries for 4 weeks that quantified exercise activity and were measured for body composition, maximal oxygen uptake, and REE. Multiple regression analysis was used to test for associations between EEE, age, body composition, and REE. There was a significant positive relation between EEE and lean tissue mass (fat-free mass and fat-free mass index). The relation between REE and EEE remained significant even after controlling for lean tissue mass. These results support the hypothesis that exercise is positively associated with REE and can counter the negative effects of age and menopause. They also indicate a continuous relation between exercise and REE across ranges of exercise, from moderate to high. Exercise at levels that are at or above current clinical guidelines might, in part, ameliorate the risk for energy imbalance and metabolic disease because of its positive relation with REE.

Pulmonary cachexia is a prevalent, debilitating and well-recognized feature of COPD associated with increased mortality and loss of peripheral and respiratory muscle function. The exact cause and underlying mechanisms of cachexia in COPD are still poorly understood. Increasing evidence however shows that pathological changes in intra-cellular mechanisms of muscle mass maintenance (i.e. protein turn-over and myonuclear turn-over) are likely involved. Potential factors triggering alterations in these mechanisms in COPD include oxidative stress, myostatin and inflammation. In addition to muscle wasting, peripheral muscle in COPD is characterized by a fiber-type shift towards a more type II, glycolytic phenotype and an impaired oxidative capacity (collectively referred to as an impaired oxidative phenotype). Atrophied diaphragm muscle in COPD, however, displays an enhanced oxidative phenotype. Interestingly, intrinsic abnormalities in (lower limb) peripheral muscle seem more pronounced in either cachectic patients or weight-loss susceptible emphysema patients, suggesting that muscle wasting and intrinsic changes in peripheral muscle's oxidative phenotype are somehow intertwined. In this manuscript, we will review alterations in mechanisms of muscle mass maintenance in COPD and discuss the involvement of oxidative stress, inflammation and myostatin as potential triggers of cachexia. Moreover, we postulate that an impaired muscle oxidative phenotype in COPD can accelerate the process of cachexia, as it renders muscle in COPD less energy-efficient thereby contributing to an energy-deficit and weight loss when not dietary compensated. Furthermore, loss of peripheral muscle oxidative phenotype may increase the muscle's susceptibility to inflammation- and oxidative stress-induced muscle damage and wasting.

Weight loss resulting from an exercise intervention tends to be lower than predicted. Modest weight loss can arise from an increase in energy intake, physiological reductions in resting energy expenditure, an increase in lean tissue or a decrease in non-exercise activity. Lower than expected, weight loss could also arise from weak and invalidated assumptions within predictive models. To investigate these causes, we systematically reviewed studies that monitored compliance to exercise prescriptions and measured exercise-induced change in body composition. Changed body energy stores were calculated to determine the deficit between total daily energy intake and energy expenditures. This information combined with available measurements was used to critically evaluate explanations for low exercise-induced weight loss. We conclude that the small magnitude of weight loss observed from the majority of evaluated exercise interventions is primarily due to low doses of prescribed exercise energy expenditures compounded by a concomitant increase in caloric intake.

The idea of body weight regulation implies that a biological mechanism exerts control over energy expenditure and food intake. This is a central tenet of energy homeostasis. However, the source and identity of the controlling mechanism have not been identified, although it is often presumed to be some long-acting signal related to body fat, such as leptin. Using a comprehensive experimental platform, we have investigated the relationship between biological and behavioural variables in two separate studies over a 12-week intervention period in obese adults (total n 92). All variables have been measured objectively and with a similar degree of scientific control and precision, including anthropometric factors, body composition, RMR and accumulative energy consumed at individual meals across the whole day. Results showed that meal size and daily energy intake (EI) were significantly correlated with fat-free mass (FFM, P values ,0·02–0·05) but not with fat mass (FM) or BMI (P values 0·11–0·45) (study 1, n 58). In study 2 (n 34), FFM (but not FM or BMI) predicted meal size and daily EI under two distinct dietary conditions (high-fat and low-fat). These data appear to indicate that, under these circumstances, some signal associated with lean mass (but not FM) exerts a determining effect over self-selected food consumption. This signal may be postulated to interact with a separate class of signals generated by FM. This finding may have implications for investigations of the molecular control of food intake and body weight and for the management of obesity.