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Objective: This trial aimed to compare three low-energy diets (LEDs) with different amounts of carbohydrates (CHO) on ketosis and changes in hunger feelings in adults with obesity., Methods: A total of 101 adults (51 female) with obesity (BMI, mean [SEM], 34.7 [0.4] kg/m 2 ) were randomized to follow three isocaloric LEDs (1000 kcal/day) for 8 weeks, containing either low, medium, or high CHO (70, 100, and 130 g/day, respectively), and 4 weeks of refeeding and weight stabilization. Body weight (BW) and composition, hunger and other appetite ratings, concentrations of β-hydroxybutyrate (βHB), and appetite-related hormones were measured at baseline and at the end of weeks 8 and 12., Results: At week 8, weight loss and βHB concentrations were significantly different among groups: Low CHO group versus Medium CHO group (BW: 2.32 [0.95] kg, 95% CI: 0.44 to 4.21, p = 0.016; βHB: -0.40 [0.09] mM, 95% CI: -0.67 to -0.09, p < 0.001); Low CHO group versus High CHO group (BW: 2.29 [0.96] kg, 95% CI: 0.39 to 4.19, p = 0.016; βHB: -0.644 [0.10] mM, 95% CI: -0.84 to -0.44, p < 0.001); and Medium CHO group versus High CHO group (BW: -0.03 [0.94] kg, 95% CI: -1.89 to 1.84, p = 0.977; βHB: -0.15 [0.08] mM, 95% CI: -0.30 to 0.002, p = 0.054). No significant differences in hunger were found among groups: Low CHO group versus Medium CHO group (-10.87 [5.92] mm, 95% CI: -0.82 to 22.57, p = 0.068); Low CHO group versus Medium CHO group (7.74 [7.36] mm, 95% CI: -6.77 to 22.26, p = 0.294); and Medium CHO group versus High CHO group (-3.13 [7.48] mm, 95% CI: -17.89 to 11.63, p = 0.676)., Conclusions: Although the findings of this trial are not definitive, changes in hunger ratings with weight loss did not differ among groups. Additional studies with CHO intake of up to 130 g in 1000-kcal/day LEDs are warranted to replicate these findings., (© 2024 The Author(s). Obesity published by Wiley Periodicals LLC on behalf of The Obesity Society.)

The aim of this study was to determine the efficacy, safety and acceptability of a 4-week very-low-energy diet (VLED) program for adolescents with obesity. Adolescents (13-17 years) with obesity and ≥1 obesity-related complication were Fast Track to Health 52-week randomized controlled trial participants. Adolescents undertook a 4-week micronutrient-complete VLED (800 kcal/day), with weekly dietitian support. Anthropometric data were recorded at baseline and week-4 and side-effects at day 3-4, week-1, -2, -3 and -4. Adolescents completed an acceptability survey at week-4. A total of 134 adolescents (14.9 ± 1.2 years, 50% male) had a 5.5 ± 2.9 kg ( p < 0.001) mean weight loss at week-4: 95% experienced ≥1 and 70% experienced ≥3 side-effects during the VLED program, especially during the first week. Hunger, fatigue, headache, irritability, loose stools, constipation and nausea were most common. Reporting more side-effects at day 3-4 correlated with greater weight loss at week-4 (r = -0.188, p = 0.03). Adolescents reported 'losing weight' (34%) and 'prescriptive structure' (28%) as the most positive aspects of VLED, while 'restrictive nature' (45%) and 'meal replacement taste' (20%) were least liked. A dietitian-monitored short-term VLED can be implemented safely and is acceptable for many adolescents seeking weight loss, despite frequent side-effects. Investigating predictors of acceptability and effectiveness could determine adolescents most suited to VLED programs.

Developing a broader understanding of children and young people's experiences of long-term attempts of weight management may provide insight into both enablers and barriers to successful weight loss maintenance. This review aims to explore children and young people's perceptions of long-term attempts of weight management. Six databases were searched for qualitative studies describing young participants (<25 years, previously or currently above a healthy weight) experiences of weight management for >6 months following intentional weight loss. A thematic synthesis was undertaken. Themes were interpreted using the Socio-ecological Model. Factors supporting attempts to maintain weight loss included having clear motivation for change; developing personal skills to manage the challenges of change; family support/dynamics that encourage healthy lifestyles; and health-promoting cultures in schools/workplaces, communities, and the broader living environment. Conversely, ambivalence, difficulty coping with changes, peer pressure, challenging family dynamics, limited professional support, and unhealthy living environments were barriers to maintaining behavior change. These facilitators and barriers at each level of the Socio-ecological Model informed a model of weight loss maintenance for children and young people. Supporting children, young people, and families to develop the skills to manage the individual, social, and environmental challenges that shape attempts of long-term weight management will help to support their ability to manage their weight long term., (© 2020 World Obesity Federation.)

Objective: The purpose of this study was to examine whether the degree of ketosis, measured as plasma β-hydroxybutyrate (βHB) in fasting, was associated with changes in appetite feelings and plasma concentration of appetite-related hormones after weight loss., Methods: A total of 87 individuals with obesity (BMI: 36.5 ± 4.0 kg/m 2 ; age: 42.4 ± 9.7 years; 39 males) underwent 8 weeks of a very low-energy diet. Body weight/composition, plasma concentration of βHB, and appetite-related hormones (active ghrelin, active glucagon-like peptide 1 [GLP-1], total peptide YY, cholecystokinin [CCK], and insulin) and subjective appetite feelings were measured at baseline and week 9., Results: Participants lost 17.7 ± 4.1 kg and were ketotic (βHB: 1.24 ± 0.82 mmol/L in fasting) at week 9. A negative association was found between βHB in fasting at week 9 and changes in basal (r = -0.315, P = 0.003) and postprandial ghrelin concentration (r = -0.286, P = 0.008), and a positive association was found with the change in postprandial GLP-1 (r = 0.244, P = 0.025) and CCK (r = 0.228, P = 0.035). No association was seen between βHB in fasting and changes in peptide YY or subjective feelings of appetite., Conclusions: βHB plasma concentration in fasting is associated with lower concentrations of the hunger hormone ghrelin and increased concentrations of the satiety hormones GLP-1 and CCK. Future studies should explore the molecular mechanisms by which βHB modulates the secretion of gut hormones., (© 2020 The Authors. Obesity published by Wiley Periodicals LLC on behalf of The Obesity Society (TOS).)

This review seeks to synthesise our knowledge about changes in hunger and satiety that occur during diet-induced weight loss and during weight loss maintenance, with a particular focus on youth with obesity. Mechanisms of appetite responses to weight loss rely heavily on the adult literature. Physiological mechanisms that control appetite and satiety via the gut-brain axis have been elucidated but we have an incomplete picture of changes in gut hormones and peptides in youth with obesity. In adolescents, the role of the brain in long-term sensing of body composition and modifying appetite and satiety changes is easily over-ridden by hedonic influences for the reward of highly palatable sweet foods and encourages over-consumption. Accordingly, reward cues and hyper-responsiveness to palatable foods lead to a pattern of food choices. Different reward systems are necessary that are substantial enough to reward the continued individual effort required to sustain new behaviours, that need to be adopted to support a reduced body weight. Periods of growth and development during childhood provide windows of opportunity for interventions to influence body weight trajectory but long-term studies are lacking. More emphasis needs to be placed on anticipatory guidance on how to manage powerful hedonic influences of food choice, essential to cope with living in our obesogenic environment and managing hunger which comes with the stronger desire to eat after weight has been lost.

Objective: To compare appetite markers in reduced-obese individuals with a nonobese control group., Methods: A total of 34 adults with obesity who lost 17% body weight at week 13 and maintained this weight loss (WL) at 1 year were compared with 33 nonobese controls matched for body composition. Basal and postprandial subjective appetite ratings and appetite-related hormone concentrations (ghrelin, total peptide YY, peptide YY3-36, total and active glucagon-like peptide 1, and cholecystokinin) were measured in all participants and repeated at week 13 and 1 year in the weight-reduced group., Results: WL led to a reduction in prospective food consumption and an increase in feelings of hunger, fullness, and ghrelin secretion (basal and postprandial), but these new ratings were no different from those seen in controls. Postprandial concentrations of active glucagon-like peptide 1, total peptide YY, and cholecystokinin were lower in individuals with obesity at all time points compared with controls., Conclusion: The increased drive to eat (both subjective feelings of hunger and ghrelin concentrations) seen in reduced-obese individuals, both after acute and sustained WL, reflects a normalization toward a lower body weight. Overall, WL does not have a sustained negative impact on satiety peptide secretion, despite a blunted secretion in individuals with obesity compared with nonobese controls., (© Endocrine Society 2020.)

Background: Intermittent energy restriction (IER) has shown early success in adolescents with obesity, however efficacy trials are needed. This study aims to determine if IER results in lower body mass index (BMI) z-score after 52 weeks in metabolically unhealthy adolescents with obesity compared with continuous energy restriction (CER)., Methods/design: This is a prospective, randomised, multi-centre trial conducted in tertiary care settings, with three phases: jumpstart (weeks 0-4); intensive intervention (weeks 5-16); continued intervention and/or maintenance (weeks 17-52). During the jumpstart phase, all participants follow a very low energy diet (∼800kcal/3350kJ/day), then transition to their allocated intervention: IER or CER. IER involves three energy-restricted days/week, consuming one-third of daily energy requirements (∼600-700kcal/2500-2950kJ/day), and four days/week of a healthy meal plan. The CER, which is current standard care, has individually tailored energy prescription based on age and sex (13-14years, 1430-1670kcal/6000-7000kJ/day; 15-17years, 1670-1900kcal/7000-8000kJ/day). The study will recruit 186 (93 per arm) treatment-seeking adolescents aged 13-17years with obesity and at least one metabolic co-morbidity. The primary outcome is change in BMI z-score at 52 weeks. Secondary outcomes are changes at 4, 16 and 52 weeks in: body composition; diet quality, food choices and food patterns; cardio-metabolic risk factors; physical activity and sedentary behaviour; sleep and psycho-behavioural measures., Discussion: This study challenges existing clinical paradigms that CER is the only method for weight management in metabolically unhealthy adolescents. If successful, IER may offer an alternate medical nutrition therapy approach for those seeking treatment in tertiary settings., Clinical Trial Registration Number: ACTRN12617001630303., (Copyright © 2019. Published by Elsevier Ltd.)

Background: Diet-induced weight loss (WL) is usually accompanied by increased appetite, a response that seems to be absent when ketogenic diets are used. It remains unknown if sex modulates the appetite suppressant effect of ketosis., Objective: The aim of this study was to examine if sex modulates the impact of WL-induced changes in appetite and if ketosis alters these responses., Methods: Ninety-five individuals (55 females) with obesity (BMI [kg/m 2]: 37  ± 4) underwent 8 wk of a very-low-energy diet, followed by 4 wk of refeeding and weight stabilization. Body composition, plasma concentration of β-hydroxybutyrate (β-HB) and appetite-related hormones (active ghrelin, active glucagon-like peptide 1 [GLP-1], total peptide YY [PYY], cholecystokinin and insulin), and subjective feelings of appetite were measured at baseline, week 9 in ketosis, and week 13 out of ketosis., Results: The mean WL at week 9 was 17% for males and 15% for females, which was maintained at week 13. Weight, fat, and fat-free mass loss were greater in males (P < 0.001 for all) and the increase in β-HB at week 9 higher in females (1.174 ± 0.096 compared with 0.783 ± 0.112 mmol/L, P = 0.029). Basal and postprandial GLP-1 and postprandial PYY (all P < 0.05) were significantly different for males and females. There were no significant sex × time interactions for any other appetite-related hormones or subjective feelings of appetite. At week 9, basal GLP-1 was decreased only in males (P < 0.001), whereas postprandial GLP-1 was increased only in females (P < 0.001). No significant changes in postprandial PYY were observed over time for either sex., Conclusions: Ketosis appears to have a greater beneficial impact on GLP-1 in females. However, sex does not seem to modulate the changes in the secretion of other appetite-related hormones, or subjective feelings of appetite, seen with WL, regardless of the ketotic state. This trial was registered at clinicaltrials.gov as NCT01834859., (Copyright © American Society for Nutrition 2019.)

Background & Aims: Rapid weight loss (WL) has been associated with a larger loss of fat free mass and a disproportional reduction in resting metabolic rate (RMR), but the evidence is inconclusive. We aimed to evaluate the impact of WL rate on body composition and compensatory mechanisms activated with WL (reduced RMR, increased exercise efficiency (ExEff) and appetite), both during negative and neutral energy balance (EB)., Methods: Thirty-five participants with obesity were randomized to lose a similar weight rapidly (4 weeks) or gradually (8 weeks), and afterwards to maintain it (4 weeks). Body weight and composition, RMR, ExEff (10, 25 and 50 W), appetite feelings and appetite-regulating hormones (active ghrelin, cholecystokinin, total peptide YY (PYY), active glucagon-like peptide-1 and insulin), in fasting and every 30 min up to 2.5 h, were measured at baseline and after each phase., Results: Changes in body weight (≈9%) and composition were similar in both groups. With WL, RMR decreased and ExEff at 10 W increased significantly in the rapid WL group only. However, fasting hunger increased significantly with gradual WL only, while fasting and postprandial prospective food consumption, and postprandial hunger decreased (and postprandial fullness increased) significantly with rapid WL only. Basal total PYY, and basal and postprandial insulin decreased significantly, and similarly in both groups. After weight stabilization and no ketosis no differences between groups were found., Conclusions: Despite differences while under negative EB, WL rate does not seem to have a significant impact on body composition or on compensatory mechanisms, once EB is reestablished., Clinical Trial Registration Number: NCT01912742 (the study was registered in clinicaltrial.gov)., (Copyright © 2017 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.)

Background/objective: Diet-induced weight loss (WL) leads to a compensatory increase in appetite and changes in the plasma concentration of appetite-regulating hormones are likely to play a role. Whether these changes are transient or sustained remains unclear. This study aimed to assess if changes in subjective and objective appetite markers observed with WL are sustained after 1 year (1Y)., Subjects/methods: In total 100 (45 males) individuals with obesity (BMI: 37 ± 4 kg/m 2 , age: 43 ± 10 years) underwent 8 weeks (wks) of a very-low energy diet (VLED), followed by 4 wks refeeding, and a 1Y maintenance program. Fasting/postprandial subjective ratings of hunger, fullness, desire to eat, and prospective food consumption (PFC) were assessed, and plasma concentration of active ghrelin (AG), total peptide YY (PYY), active glucagon-like peptide 1, cholecystokinin (CCK), and insulin measured, at baseline, week 13 (Wk13) and 1Y., Results: At Wk13, 16% WL (-18 ± 1 kg, P < 0.001) was associated with a significant increase in fasting and postprandial hunger ratings (P < 0.01 and P < 0.05, respectively), and postprandial fullness (P < 0.01) combined with a reduction in PFC (P < 0.001). These were accompanied by a significant rise in basal and postprandial AG concentrations (P < 0.001, for both), a reduction in postprandial CCK (P < 0.01) and in basal and postprandial insulin (P < 0.001). At 1Y follow-up, with sustained WL (15%; -16 ± 1 kg, P < 0.001), fasting hunger and postprandial fullness ratings remained increased (P < 0.05 for both), and postprandial PFC reduced (P < 0.001). Basal and postprandial AG remained elevated and insulin reduced (P < 0.001, for all), while postprandial CCK was increased (P < 0.01) and PYY decreased (P < 0.001)., Conclusion: With a 15% sustained WL at 1Y, the drive to eat in the fasting state is increased, but this may be balanced out by raised postprandial feelings of fullness. To assist with WL maintenance, new strategies are required to manage increased hunger and drive to eat.

Diet-induced weight loss (WL) is associated with reduced resting and non-resting energy expenditure (EE), driven not only by changes in body composition but also potentially by adaptive thermogenesis (AT). When exactly this happens, during progressive WL, remains unknown. The aim of this study was to determine the timeline of changes in RMR and exercise-induced EE (EIEE), stemming from changes in body composition v. the presence of AT, during WL with a very-low-energy diet (VLED). In all, thirty-one adults (eighteen men) with obesity (BMI: 37 (sem 4·5) kg/m2; age: 43 (sem 10) years) underwent 8 weeks of a VLED, followed by 4 weeks of weight maintenance. Body weight and composition, RMR, net EIEE (10, 25 and 50 W) and AT (for RMR (ATRMR) and EIEE (ATEIEE)) were measured at baseline, day 3 (2 (sem 1) % WL), after 5 and 10 % WL and at weeks 9 (16 (sem 2) %) and 13 (16 (sem 1) %). RMR and fat mass were significantly reduced for the first time at 5 % WL (12 (sem 8) d) (P<0·01 and P<0·001, respectively) and EIEE at 10 % WL (32 (sem 8) d), for all levels of power (P<0·05), and sustained up to week 13. ATRMR was transiently present at 10 % WL (-460 (sem 690) kJ/d, P<0·01). A fall in RMR should be anticipated at ≥5 % WL and a reduction in EIEE at ≥10 % WL. Transient ATRMR can be expected at 10 % WL. These physiological adaptations may make progressive WL difficult and will probably contribute to relapse.

Background & Aims: Strong compensatory responses, with reduced resting metabolic rate (RMR), increased exercise efficiency (ExEff) and appetite, are activated when weight loss (WL) is achieved with continuous energy restriction (CER), which try to restore energy balance. Intermittent energy restriction (IER), where short spells of energy restriction are interspaced by periods of habitual energy intake, may offer some protection in minimizing those responses. We aimed to compare the effect of IER versus CER on body composition and the compensatory responses induced by WL., Methods: 35 adults (age: 39 ± 9 y) with obesity (BMI: 36 ± 4 kg/m 2 ) were randomized to lose a similar weight with an IER (N = 18) or a CER (N = 17) diet over a 12 week period. Macronutrient composition and overall energy restriction (33% reduction) were similar between groups. Body weight/composition, RMR, fasting respiratory quotient (RQ), ExEff (10, 25, and 50 W), subjective appetite ratings (hunger, fullness, desire to eat, and prospective food consumption (PFC)), and appetite-regulating hormones (active ghrelin (AG), cholecystokinin (CCK), total peptide YY (PYY), active glucagon-like peptide-1 (GLP-1), and insulin) were measured before and after WL., Results: Changes in body weight (≈12.5% WL) and composition were similar in both groups. Fasting RQ and ExEff at 10 W increased in both groups. Losing weight, either by IER or CER dieting, did not induce significant changes in subjective appetite ratings. RMR decreased and ExEff at 25 and 50 W increased (P < 0.001 for all) in IER group only. Basal and postprandial AG increased (P < 0.05) in IER group, whereas basal active GLP-1 decreased (P = 0.033) in CER group only. Postprandial CCK decreased in both groups (P = 0.0012 and P = 0.009 for IER and CER groups, respectively). No between group differences were apparent for any of the outcomes., Conclusions: The technique used to achieve energy restriction, whether it is continuous or intermittent, does not appear to modulate the compensatory mechanisms activated by weight loss., Clinical Trial Registration Number: NCT02169778 (the study was registered in clinicaltrial.gov)., (Copyright © 2017 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.)

Objective: This study aimed to (1) compare the willingness to expend effort for rewards between young adults with healthy weight, overweight, and obesity; and (2) to examine how individual differences in the willingness to expend effort for rewards predict adherence to weight loss treatment., Methods: Seventy-three participants completed the Effort Expenditure for Rewards Task (EEfRT). Of those 73 participants, 42 young adults with excess weight took part in a 3-month weight loss treatment after completing the EEfRT. Generalized estimating equation models were used to compare the groups with healthy weight, overweight, and obesity in the EEfRT. Logistic regression models, including the proportion of hard-task choices for each reward probability condition as predictors (12%, 50%, and 88%), were conducted to longitudinally predict adherence in the treatment., Results: Young adults with obesity were significantly less willing to expend effort for high-magnitude rewards compared with participants with overweight (P = 0.05). The willingness to expend effort for uncertain rewards (50% probability) was distinguished between completers and dropouts in the weight loss treatment (χ 2  = 5.04, P < 0.02)., Conclusions: Young adults with obesity, compared with their counterparts with overweight, have diminished motivation to expend effort for obtaining high-magnitude rewards. Less willingness to expend effort for the most uncertain rewards predicts poor adherence to weight loss treatment., (© 2017 The Obesity Society.)

Background/objective: Diet-induced weight loss (WL) leads to increased hunger and reduced fullness feelings, increased ghrelin and reduced satiety peptides concentration (glucagon-like peptide-1 (GLP-1), cholecystokinin (CCK) and peptide YY (PYY)). Ketogenic diets seem to minimise or supress some of these responses. The aim of this study was to determine the timeline over which changes in appetite occur during progressive WL with a ketogenic very-low-energy diet (VLED)., Subjects/methods: Thirty-one sedentary adults (18 men), with obesity (body mass index: 37±4.5 kg m -2 ) underwent 8 weeks (wks) of a VLED followed by 4 wks of weight maintenance. Body weight and composition, subjective feelings of appetite and appetite-related hormones (insulin, active ghrelin (AG), active GLP-1, total PYY and CCK) were measured in fasting and postprandially, at baseline, on day 3 of the diet, 5 and 10% WL, and at wks 9 and 13. Data are shown as mean±s.d., Results: A significant increase in fasting hunger was observed by day 3 (2±1% WL), (P<0.01), 5% WL (12±8 days) (P<0.05) and wk 13 (17±2% WL) (P<0.05). Increased desire to eat was observed by day 3 (P<0.01) and 5% WL (P<0.05). Postprandial prospective food consumption was significantly reduced at wk 9 (16±2% WL) (P<0.01). Basal total PYY was significantly reduced at 10% WL (32±8 days) (P<0.05). Postprandial active GLP-1 was increased at 5% WL (P<0.01) and CCK reduced at 5 and 10% WL (P<0.01, for both) and wk 9 (P<0.001). Basal and postprandial AG were significantly increased at wk 13 (P<0.001, both)., Conclusions: WL with a ketogenic VLED transiently increases the drive to eat up to 3 weeks (5% WL). After that, and while participants are ketotic, a 10-17% WL is not associated with increased appetite. However, hunger feelings and AG concentrations increase significantly from baseline, once refeeding occurs.

Objective: Adolescent obesity is difficult to treat and the optimal dietary pattern, particularly in relation to macronutrient composition, remains controversial. This study tested the effect of two structured diets with differing macronutrient composition versus control, on weight, body composition and metabolic parameters in obese adolescents., Design: A randomized controlled trial conducted in a children's hospital., Methods: Eighty seven obese youth (means: age 13.6 years, BMI z-score 2.2, waist: height ratio 0.65, 69% female) completed a psychological preparedness program and were then randomized to a short term 'structured modified carbohydrate' (SMC, 35% carbohydrate; 30% protein; 35% fat, n = 37) or a 'structured low fat' (SLF, 55% carbohydrate; 20% protein; 25% fat, n = 36) or a wait listed control group (n = 14). Anthropometric, body composition and biochemical parameters were measured at randomization and after 12 weeks, and analyzed under the intention to treat principle using analysis of variance models., Results: After 12 weeks, data was collected from 79 (91%) participants. BMI z-scores were significantly lower in both intervention groups compared to control after adjusting for baseline values, SLF vs. control, mean difference = -0.13 (95%CI = -0.18, -0.07), P<0.001; SMC vs. control, -0.14 (-0.19, -0.09), P<0.001, but there was no difference between the two intervention diet groups: SLF vs. SMC, 0.00 (-0.05, 0.04), P = 0.83., Conclusions: Both dietary patterns resulted in similar changes in weight, body composition and metabolic improvements compared to control. The use of a structured eating system which allows flexibility but limited choices can assist in weight change and the rigid application of a low fat eating pattern is not exclusive in its efficacy., Trial Registration: International Clinical Trials Registry ISRCTN49438757.

Objective: To explore which baseline physiological and psychosocial variables predict change in body mass index (BMI) z-score in obese youth after 12 weeks of a dietary weight management study., Methods: Participants were obese young people participating in a dietary intervention trial in Brisbane Australia. The outcome variable was change in BMI z-score. Potential predictors considered included demographic, physiological and psychosocial parameters of the young person, and demographic characteristics of their parents. A multivariable regression model was constructed to examine the effect of potential predictive variables., Results: Participants (n = 88) were predominantly female (69.3%), and had a mean(standard deviation) age of 13.1(1.9) years and BMI z-score of 2.2(0.4) on presentation. Lower BMI z-score (p < 0.001) and insulin resistance (p = 0.04) at baseline, referral from a paediatrician (p = 0.02) and being more socially advantaged (p = 0.046) were significantly associated with weight loss. Macronutrient distribution of diet and physical activity level did not contribute., Conclusions: Early intervention in obesity treatment in young people improves likelihood of success. Other factors such as degree of insulin resistance, social advantage and referral source also appear to play a role. Assessing presenting characteristics and factors associated with treatment outcome may allow practicing clinicians to individualise a weight management program or determine the 'best-fit' treatment for an obese adolescent., (© 2013 Asian Oceanian Association for the Study of Obesity . Published by Elsevier Ltd. All rights reserved.)

Background: Despite the recognition of obesity in young people as a key health issue, there is limited evidence to inform health professionals regarding the most appropriate treatment options. The Eat Smart study aims to contribute to the knowledge base of effective dietary strategies for the clinical management of the obese adolescent and examine the cardiometablic effects of a reduced carbohydrate diet versus a low fat diet., Methods and Design: Eat Smart is a randomised controlled trial and aims to recruit 100 adolescents over a 2 1/2 year period. Families will be invited to participate following referral by their health professional who has recommended weight management. Participants will be overweight as defined by a body mass index (BMI) greater than the 90th percentile, using CDC 2000 growth charts. An accredited 6-week psychological life skills program 'FRIENDS for Life', which is designed to provide behaviour change and coping skills will be undertaken prior to volunteers being randomised to group. The intervention arms include a structured reduced carbohydrate or a structured low fat dietary program based on an individualised energy prescription. The intervention will involve a series of dietetic appointments over 24 weeks. The control group will commence the dietary program of their choice after a 12 week period. Outcome measures will be assessed at baseline, week 12 and week 24. The primary outcome measure will be change in BMI z-score. A range of secondary outcome measures including body composition, lipid fractions, inflammatory markers, social and psychological measures will be measured., Discussion: The chronic and difficult nature of treating the obese adolescent is increasingly recognised by clinicians and has highlighted the need for research aimed at providing effective intervention strategies, particularly for use in the tertiary setting. A structured reduced carbohydrate approach may provide a dietary pattern that some families will find more sustainable and effective than the conventional low fat dietary approach currently advocated. This study aims to investigate the acceptability and effectiveness of a structured reduced dietary carbohydrate intervention and will compare the outcomes of this approach with a structured low fat eating plan., Trial Registration: The protocol for this study is registered with the International Clinical Trials Registry (ISRCTN49438757).

Objective: To investigate the relative efficacy of four popular weight-loss programmes on plasma lipids and lipoproteins as measures of CVD risk., Design: A multi-centred, randomised, controlled trial of four diets - Dr Atkins' New Diet Revolution, The Slim-Fast Plan, Weight Watchers Pure Points programme and Rosemary Conley's 'Eat yourself Slim' Diet and Fitness Plan - against a control diet, in parallel for 6 months., Setting and Subjects: The trial was conducted at five universities across the UK (Surrey, Nottingham, Ulster (Coleraine), Bristol and Edinburgh (Queen Margaret University College)) and involved the participation of 300 overweight and obese males and females aged 21-60 years in a community setting., Results: Significant weight loss was achieved by all dieting groups (5-9 kg at 6 months) but no significant difference was observed between diets at 6 months. The Weight Watchers and Rosemary Conley (low-fat) diets were followed by significant reductions in plasma LDL cholesterol (both -12.2 % after 6 months, P < 0.01), whereas the Atkins (low-carbohydrate) and Weight Watchers diets were followed by marked reductions in plasma TAG (-38.2 % and -22.6 % at 6 months respectively, P < 0.01). These latter two diets were associated with an increase in LDL particle size, a change that has been linked to reduced CVD risk., Conclusions: Overall, these results demonstrate the favourable effects of weight loss on lipid-mediated CVD risk factors that can be achieved through commercially available weight-loss programmes. No detrimental effects on lipid-based CVD risk factors were observed in participants consuming a low-carbohydrate diet.

Objective: To investigate the effect of commercial weight loss programmes on macronutrient composition and micronutrient adequacy over a 2 month period., Design: Adults were randomly allocated to follow the Slim Fast Plan, Weight Watchers Pure Points Programme, Dr Atkins' New Diet Revolution, or Rosemary Conley's "Eat Yourself Slim" Diet & Fitness Plan., Setting: A multi-centre randomised controlled trial., Subjects: 293 adults, mean age 40.3 years and a mean BMI 31.7 (range 27-38) were allocated to follow one of the four diets or control group. Subjects completed a 7-day food and activity diary at baseline (prior to randomisation) and after 2 months. Diet records were analysed for nutrient composition using WinDiets (research version)., Results: A significant shift in the macronutrient composition of the diet with concurrent alteration of the micronutrient profile was apparent with all diets. There was no evidence to suggest micronutrient deficiency in subjects on any of the dietary regimens. However, those sub-groups with higher needs for specific micronutrients, such as folate, iron or calcium may benefit from tailored dietary advice., Conclusion: The diets tested all resulted in considerable macronutrient change and resulted in an energy deficit indicating dietary compliance. Health professionals and those working in community and public health should be reassured of the nutritional adequacy of the diets tested., Trial Registration Number: NCT00327821.

Background: This study investigated differences in weight loss outcomes in obese women with Type 2 diabetes (T2D) compared to those without T2D attending a 6-month dietetic led 'Lifestyle' intervention. In those who had failed to reach weight loss goals using the 'Lifestyle' approach, the study further examined the effect on weight loss with the addition of sibutramine (Reductil, Abbott Laboratories, USA) over a 6-month period., Methods: The study comprised a case-control analysis of data from 38 obese female patients (18 with T2D) from the 'Lifestyle' and 'Pharmacotherapy' clinics attending a tertiary hospital in the UK., Results: In the 'Lifestyle' treatment groups, those with T2D lost significantly less body weight than those without T2D [5.26 kg (4.54%) versus 9.89 kg (9.55%), respectively]. For subjects who had failed to lose weight via the 'Lifestyle' intervention, the addition of sibutramine resulted in a similar weight loss compared to their pair-matched 'Lifestyle' only 'successful' counterparts (9.66% versus 9.55%)., Conclusions: Not all obese women, and those with T2D in particular, will derive benefit from 'Lifestyle' advice and those who are resistant to this treatment approach may be assisted by pharmacotherapy. Dietitians can play a role in identifying those individuals who may benefit from the use of pharmacotherapy.

Objectives: To investigate the previous dieting experiences and expectations of individuals enrolled in a randomized trial of four commercial weight loss programmes and post-intervention to compare experiences across the diet groups., Aim: The purpose of this study was to enhance the understanding of why subjects volunteered to take part in a weight loss trial and also to ascertain their views on each of the diets tested., Methods: Focus groups containing both men and women were undertaken at baseline prior to randomization, and diet specific focus groups were held post-intervention. All group discussions were recorded and transcribed verbatim and analysed for emerging themes using the long-table approach., Results: The main intrinsic motivators to enroling in the study were a current lack of self-esteem and confidence. The opportunity to take part in an academic study was also a motivator. Motivation and increasing efficacy were cited commonly among those who had successfully lost (or at least not gained) weight. The 'pros' identified for each of the commercial diets tested in the trial were in line with each of the diet's promotional materials; the 'cons' varied between groups., Conclusion: In this study, reducing health risks was not the main motivator for people deciding to lose weight. Increasing intrinsic sense of worth gained by losing weight and continued motivation appear to be related to success. The differing experiences of people undertaking each of the four diets suggest that matching diet regimen to individual is important.

Background Gut hormones change with weight loss in adults but are not well studied in obese youth. Objective The primary aim was to evaluate how gut hormones and subjective appetite measure change with dietary weight loss in obese adolescents. Methods Participants were a subset of those taking part in the 'Eat Smart Study'. They were aged 10-17 years with body mass index ( BMI) > 90th centile and were randomized to one of three groups: wait-listed control, structured reduced carbohydrate or structured low-fat dietary intervention for 12 weeks. Outcomes were fasting glucose, insulin, leptin, adiponectin, total amylin, acylated ghrelin, active glucagon-like peptide-1, glucose-dependent insulinotropic polypeptide ( GIP), pancreatic polypeptide ( PP) and total peptide tyrosine-tyrosine. Pre- and postprandial subjective sensations of appetite were assessed using visual analogue scales. Results Of 87 'Eat Smart' participants, 74 participated in this sub-study. The mean (standard deviation) BMI z-score was 2.1 (0.4) in the intervention groups at week 12 compared with 2.2 (0.4) in the control group. Fasting insulin ( P = 0.05) and leptin ( P = 0.03) levels decreased, while adiponectin levels increased ( P = 0.05) in the intervention groups compared with control. The intervention groups were not significantly different from each other. A decrease in BMI z-score at week 12 was associated with decreased fasting insulin ( P < 0.001), homeostatic model of assessment-insulin resistance ( P < 0.001), leptin ( P < 0.001), total amylin ( P = 0.03), GIP ( P = 0.01), PP ( P = 0.02) and increased adiponectin ( P < 0.001). There was no significant difference in appetite sensations. Conclusions Modest weight loss in obese adolescents leads to changes in some adipokines and gut hormones that may favour weight regain. [ABSTRACT FROM AUTHOR]

The growing rise in obesity and the search for solutions has led to an increase in the number of commercial weight loss programmes with differing approaches. However there is limited information available by which their efficacy has been compared in controlled studies. The 4 diets tested in this study were chosen to represent different approaches. These were the Slim-Fast Plan (a meal replacement approach), Weight Watchers Pure Points Programme (an energy controlled diet with weekly group meetings), Dr Atkins' New Diet Revolution (a self-monitored low carbohydrate eating plan) and Rosemary Conley's "Eat Yourself Slim" Diet & Fitness Plan (a low fat diet and a weekly group exercise class). The primary outcome measure was percentage of fat loss over 24 weeks, measured using dual energy x-ray absorptiometry. A total of 293 healthy people entered the randomisation process: 79 (27%) men and 214 (73%) women with an average body mass index of 31.7 kg/m² (range 27-38) and average age of 40.3 years. The results indicated that all the diets tested were effective and did produce significant weight and body fat loss compared to controls. On average men lost 9.12 kg (23% of initial body fat) and women 5.2 kg (16% of initial body fat). However, there was considerable variation in body fat loss within each diet group. This led to the average differences between the diets being quite small and not significant. No attempt was made to standardise energy intake across the groups and therefore the effects seen are due to the subjects own interpretation and compliance with the diet plan they were given. This study demonstrates that loss of body fat is possible using a variety of commercially available strategies, including the Atkins diet. However, the range of fat loss demonstrates that some subjects actually lost very little fat and some a great deal. This indicates that not every approach will suit everyone equally. If commercial weight loss programmes are to be used effectively more information is needed to direct individuals to the best strategy to suit their needs. [ABSTRACT FROM AUTHOR]

Obesity is increasing in severity and prevalence representing a major public health issue within the UK. Studies suggest that, at any one time, most US and UK adults are trying to lose or maintain weight ( ). As a result the demand for weight loss schemes is high. As obesity is most prevalent amongst low income groups ( ), the financial implication of following such programmes requires investigation. This study aimed to quantify and compare the costs incurred by subjects undertaking one of four commercially available weight loss programmes. Subjects comprised of the Surrey cohort (n = 35) of a multi-centre weight loss trial and were randomized to one of four programmes: Weight Watchers (WW), the Slim-Fast Plan, Rosemary Conley's Diet and Fitness Plan (RC) or the Dr Atkins’ New Diet Revolution (Atkins). Participants were all aged between 21 and 60 years, had an initial body mass index in the range of 27–36 kg m−2 and were otherwise healthy. Seven-day estimated food diaries were completed at baseline and after 2 months of dieting and were used to calculate the weight of food consumed. The cost was subsequently based on the prices quoted on the Tesco's website. Total food and alcohol were calculated for each subject at baseline and at 2 months and total programme cost was calculated at 2 months (food costs and any additional costs as a result of programme membership fees, supplementary vitamins, etc). Food group expenditure was calculated to investigate the contribution of meat, fruit, vegetables and alcohol to total costs and change in costs. Parametric and nonparametric statistics (according to the data distribution) were used to compare change in mean costs over time (paired t-tests, Wilcoxon signed ranks test) and by programme followed ( anova). No significant differences in baseline costs were observed between the four groups with whole sample mean food costs of £20.53 (SD 5.10). The Atkins group showed a significant increase in food expenditure at 2 months ( Z = −2.24, p = 0.03) whereas all other groups decreased their spending on food, significantly so for the RC and WW subjects ( Z = −1.96, p = 0.05; Z = −2.67, p = 0.01). As a result, significant differences in percentage change in food expenditure were recorded across groups ( χ2 = 16.47, p = 0.001) with the Atkins group significantly different from both RC and WW groups. Although all programmes incurred initial ‘start-up’ costs, only the Atkins diet had ongoing total programme costs at 2 months that were significantly greater than baseline expenditure. Increases in meat expenditure were significantly greater within the Atkins group compared with subjects following the other programmes ( F = 4.01, p = 0.02). However, contrary to expectations, no significant increases in spending on fruit and vegetables were seen, with a significant decrease in expenditure on fruit observed across the whole sample and within the WW group ( Z = −2.40, p = 0.02 and Z = −2.07, p = 0.04 respectively). This study suggests that commercial weight loss programmes, including those requiring the purchase of meal replacements, are not necessarily associated with an increase in food expenditure. However, the Atkins diet did result in an increase in food expenditure and as all the programmes are subject to potentially prohibitive ‘start-up’ costs, such as joining fees, the issue of access for those population groups most at risk from obesity remains. [ABSTRACT FROM AUTHOR]