Changes in fat-free mass during significant weight loss: a systematic review

A Review of Psychosocial Risk Factors Among Transgender Patients Seeking Bariatric Surgery

As nearly one third of transgender individuals in the USA are obese, more transgender patients may pursue bariatric surgery as a means of sustaining weight loss. Transgender individuals, like bariatric surgery patients, have high rates of mood pathology, substance use, abuse, and self-harm behaviors. However, there is no research on transgender bariatric surgery candidates. The aim of this review is to elucidate potential psychosocial risk factors, including sex hormone management, which may impact surgical clearance, presurgical psychosocial assessment, and treatment recommendations.

The influence of skeletal muscle on appetite regulation

INTRODUCTION

Fat-free mass, of which skeletal muscle is amajor component, correlates positively with energy intake at energy balance. This is due to the effects of metabolically active tissue on energy expenditure which in itself appears to signal to the brain adrive to eat to ensure cellular energy homeostasis. The mechanisms responsible for this drive to eat are unknown but are likely to be related to energy utilization. Here muscle imparts an indirect influence on hunger. The drive to eat is also enhanced after muscle loss secondary to intentional weight loss. The evidence suggests loss of both fat mass and skeletal muscle mass directly influences the trajectory and magnitude of weight regain highlighting their potential role in long-termappetite control. The mechanisms responsible for the potential direct drive to eat stemming from muscle loss are unknown.

AREAS COVERED

The literature pertaining to muscle and appetite at energy balance and after weight loss was examined. Aliterature search was conducted to identify studies related to appetite, muscle, exercise, and weight loss.

EXPERT OPINION

Understanding the mechanisms which link energy expenditure and muscle loss to hunger has the potential to positively impact both the prevention and the treatment of obesity.

Associations between the rate, amount, and composition of weight loss as predictors of spontaneous weight regain in adults achieving clinically significant weight loss: A systematic review and meta-regression

Weight regain following weight loss is common although little is known regarding the associations between amount, rate, and composition of weight loss and weight regain. Forty-three studies (52 groups; n = 2379) with longitudinal body composition measurements were identified in which weight loss (≥5%) and subsequent weight regain (≥2%) occurred. Data were synthesized for changes in weight and body composition. Meta-regression models were used to investigate associations between amount, rate, and composition of weight loss and weight regain. Individuals lost 10.9% of their body weight over 13 weeks composed of 19.6% fat-free mass, followed by a regain of 5.4% body weight over 44 weeks composed of 21.6% fat-free mass. Associations between the amount (P < 0.001) and rate (P = 0.049) of weight loss and their interaction (P = 0.042) with weight regain were observed. Fat-free mass (P = 0.017) and fat mass (P < 0.001) loss both predicted weight regain although the effect of fat-free mass was attenuated following adjustment. The amount (P < 0.001), but not the rate of weight loss (P = 0.150), was associated with fat-free mass loss. The amount and rate of weight loss were significant and interacting factors associated with weight regain. Loss of fat-free mass and fat mass explained greater variance in weight regain than weight loss alone.

Predictors of successful weight loss with relative maintenance of fat-free mass in individuals with overweight and obesity on an 8-week low-energy diet

A low-energy diet (LED) is an effective approach to induce a rapid weight loss in individuals with overweight. However, reported disproportionally large losses of fat-free mass (FFM) after an LED trigger the question of adequate protein content. Additionally, not all individuals have the same degree of weight loss success. After an 8-week LED providing 5020 kJ/d for men and 4184 kJ/d for women (84/70 g protein/d) among overweight and obese adults, we aimed to investigate the relationship between protein intake relative to initial FFM and proportion of weight lost as FFM as well as the individual characteristics associated with weight loss success. We assessed all outcomes baseline and after the LED. A total of 286 participants (sixty-four men and 222 women) initiated the LED of which 82 % completed and 70 % achieved a substantial weight loss (defined as ≥8 %). Protein intake in the range 1·0-1·6 g protein/d per kg FFM at baseline for men and 1·1-2·2 g protein/d per kg FFM at baseline for women was not associated with loss of FFM (P = 0·632). Higher Three-Factor Eating Questionnaire (TFEQ) hunger at baseline and reductions in TFEQ disinhibition and hunger during the LED were associated with larger weight loss (all P ≤ 0·020); whereas lower sleep quality at baseline predicted less successful weight loss using intention to treat analysis (P = 0·021), possibly driven by those dropping out (n 81, P = 0·067 v. completers: n 198, P = 0·659). Thus, the protein intakes relative to initial FFM were sufficient for maintenance of FFM and specific eating behaviour characteristics were associated with weight loss success.

Assessment of Physical Fitness after Bariatric Surgery and Its Association with Protein Intake and Type of Cholecalciferol Supplementation

Background and objectives: Several studies showed that there is a relationship between vitamin and mineral status and muscle strength. In particular this is the case for handgrip strength (HS) and vitamin D deficiency. In bariatric surgery there is a risk of decrease in muscle strength after surgery and also vitamin and mineral deficiencies are not uncommon. The aim of this study is to assess the effect of low vitamin 25 (OH) cholecalciferol levels, high dose cholecalciferol supplementation regime and protein intake on physical fitness, measured using handgrip strength (HS) and the shuttle walk run test (SWRT). Materials and Methods: For this retrospective study, 100 patients who have had bariatric surgery were included. Group A (n = 50) used 800 IU oral cholecalciferol per day. Group B (n = 50) used 800 IU oral cholecalciferol daily and 50,000 IU liquid cholecalciferol monthly lifelong. Both groups were matched on common variables. To measure physical fitness, we used the HS manometer of Jamar and the Shuttle Walk Run Test (SWRT) to assess physical capacity. Results: No significant differences in HS and SWRT outcomes were found between patients with serum 25 (OH) cholecalciferol < 75 nmol/L or >75 nmol/L. The postoperative HS is significantly influenced by protein intake (p = 0.017) and no significant influence was seen in outcomes of the SWRT (p = 0.447). Conclusion: We have found that serum 25 (OH) cholecalciferol and different cholecalciferol supplementation regimes do not have a significant effect on HS and SWRT before, three and 6 months after surgery. It seems that protein intake plays a more important role in maintaining adequate muscle strength.

Effect of the Health Tourism weight loss programme on body composition and health outcomes in healthy and excess-weight adults

Excess weight loss while minimising fat-free mass (FFM) loss is important for health. Travel is a particular period at risk for weight gain and for which the effects of a short-term intensive weight loss programme have not been studied. Therefore, we studied the effect of a novel, 1-week supervised health travel programme combining high volume, low-to-moderate intensity exercise and energy intake restriction on weight, body composition and health outcomes in adults. Weight was also monitored for 12 weeks after the programme. In all, thirty-six subjects (nineteen men, seventeen women) consisting of sixteen excess-weight (BMI: 27·1 (sd 1·7) kg/m2) and twenty healthy-weight (BMI: 22·3 (sd 1·8) kg/m2) individuals participated. Subjects performed 1 h of slow-paced intermittent jogging three times per d and other leisure activities, whereas consuming only provided foods without water restriction. Body mass significantly decreased from pre- to post-intervention in excess-weight and healthy-weight individuals (-3·5 (sd 1·5) and -3·5 (sd 1·3) %, respectively; P<0·001 for both), and losses were maintained at 12 weeks post-intervention in both groups (-6·3 (sd 3·8) and -1·7 (sd 4·0) %, respectively; P<0·01 for both). Fat mass also significantly decreased in both groups (excess weight: -9·2 (sd 4·6) %: healthy weight: -13·4 (sd 9·0) %; P<0·01 for both), whereas FFM was maintained. Similar improvements were observed for blood biochemistry and pressure in both groups. This short-term weight loss intervention yielded favourable outcomes in both excess- and healthy-weight adults, particularly a 3·5 % weight loss with no significant change to FFM. In addition, participants maintained weight loss for at least 12 weeks. Of multiple programme choices, the Health Tourism weight loss programme's results indicate that it is a viable option.

FGF21 decreases food intake and body weight in obese Göttingen minipigs

AIMS

The aim of this study was to assess the effect of FGF21 on food intake, body weight, body composition, glucose homeostasis, bone mineral density (BMD), cortisol and growth hormone (GH) in obese minipigs. The pig is a unique model for studying FGF21 pharmacology as it does not express UCP1, unlike mice and humans.

METHODS

Twelve obese Göttingen minipigs with a mean body weight of 91.6 ± 6.7 kg (mean ± SD) received subcutaneously either vehicle (n = 6) or recombinant human FGF21 (n = 6) once daily for 14 weeks (0.1 mg/kg for 9.5 weeks and 0.3 mg/kg for 4.5 weeks).

RESULTS

Treatment of obese minipigs with FGF21 led to a 50% reduction in food intake and a body weight loss of, on average, 18 kg compared to the vehicle group after 14 weeks of dosing. Glucose tolerance and insulin sensitivity, evaluated by intravenous glucose tolerance test, were significantly improved in the FGF21 group compared to the vehicle group at the end of the study. The plasma cortisol profile was unaffected by FGF21, whereas a small decrease in peak GH values was observed in the FGF21-treated animals after 7 to 9.5 weeks of treatment compared to the vehicle group. Whole-body BMD was not affected by 13 weeks of FGF21 dosing.

CONCLUSION

Despite a lack of UCP-1 in obese minipigs, FGF21 treatment induced a significant weight loss, primarily a result of reduction in food intake, with no adverse effect on BMD or plasma cortisol.

Effect of Ramadan Fasting on Weight and Body Composition in Healthy Non-Athlete Adults: A Systematic Review and Meta-Analysis

Background: Ramadan involves one month of fasting from sunrise to sunset. In this meta-analysis, we aimed to determine the effect of Ramadan fasting on weight and body composition. Methods: In May 2018, we searched six databases for publications that measured weight and body composition before and after Ramadan, and that did not attempt to influence physical activity or diet. Results: Data were collected from 70 publications (90 comparison groups, 2947 participants). There was a significant positive correlation between starting body mass index and weight lost during the fasting period. Consistently, there was a significant reduction in fat percentage between pre-Ramadan and post-Ramadan in people with overweight or obesity (−1.46 (95% confidence interval: −2.57 to −0.35) %, p = 0.010), but not in those of normal weight (−0.41 (−1.45 to 0.63) %, p = 0.436). Loss of fat-free mass was also significant between pre-Ramadan and post-Ramadan, but was about 30% less than loss of absolute fat mass. At 2–5 weeks after the end of Ramadan, there was a return towards, or to, pre-Ramadan measurements in weight and body composition. Conclusions: Even with no advice on lifestyle changes, there are consistent—albeit transient—reductions in weight and fat mass with the Ramadan fast, especially in people with overweight or obesity.

Effect of a Whey Protein Supplement on Preservation of Fat Free Mass in Overweight and Obese Individuals on an Energy Restricted Very Low Caloric Diet

The obesity epidemic has caused a widespread interest in strategies to achieve a healthy "high quality" weight loss, where excess fat is lost, while fat free mass (FFM) is preserved. In this study, we aimed to examine the effect of whey protein supplementation given before night sleep on FFM preservation during a 4-week (wk) period on a very low caloric diet (VLCD). Twenty-nine obese subjects (body mass index (BMI) > 28 kg/m²) completed a 4-week intervention including a VLCD and a walking program (30 min walking × 5 times per week). Subjects were randomly assigned to either control (CON, n = 15) or a whey protein supplement (PRO, 0.4 g protein/kg/day, n = 14), ingested before bedtime. Body composition (dual-energy X-ray absorptiometry, DXA), blood analysis and physical test were performed pre and post intervention. We measured nitrogen excretion in three 24 h urine collections (Day 0, 7 and 28) to assess nitrogen balance. Changes in nitrogen balance (NB) after 7 and 28 days was different between treatment groups (interaction p < 0.05). PRO was in NB after 7 days and in positive NB at day 28. In contrast, CON was in negative NB at day 7, but in NB at day 28. Nevertheless, no significant group differences were observed in the change in pre- and post-FFM measurements (-2.5 kg, [95% CI: 1.9; 3.1], p = 0.65). In conclusion, ingestion of a whey protein supplement before bedtime during a 4-week period on a VLCD improved nitrogen balance, but did not lead to any significant improvement in the quality of the weight loss in regard to observed changes in body composition and health parameters compared with controls.

Resistance Training and Protein Supplementation Increase Strength After Bariatric Surgery: A Randomized Controlled Trial

OBJECTIVE

Physical activity and dietary regimens to optimize health outcomes after bariatric surgery are not well known. This study aimed to determine whether resistance training with dietary protein supplementation is effective in maintaining body composition and physical fitness after obesity surgery.

METHODS

Seventy-six women with obesity undergoing Roux-en-Y gastric bypass were randomly assigned at the time of surgery to receive either usual care (controls [CON], n = 22), usual care and additional (whey) protein intake (PRO, n = 31), or usual care, additional protein intake, and supervised strength training for 18 weeks (PRO+EX, n = 23). The primary outcome was pre- to 6-month postsurgery change in lean body mass (by dual-energy x-ray absorptiometry). Secondary outcomes included changes in muscle strength (by one-repetition maximum testing).

RESULTS

Loss over time in lean body mass did not differ between groups (CON: mean,-8.8 kg; 95% CI: -10.1 to -7.5 kg; PRO: mean, -8.2 kg; 95% CI: -9.3 to -7.1 kg; PRO+EX: mean, -7.7 kg; 95% CI: -9.0 to -6.5 kg; P = 0.899). The increase in relative lower-limb muscle strength was higher in the PRO+EX group (+0.6 [0.3 to 0.8]) versus +0.1 (-0.1 to 0.4) and +0.2 (0.0 to 0.4) kg/kg body mass in CON and PRO groups, respectively (P = 0.021).

CONCLUSIONS

Loss in muscle strength observed after bariatric surgery can be overcome by resistance training with additional protein intake.

Exercise and Bariatric Surgery: An Effective Therapeutic Strategy

Exercise is a clinically effective adjunct therapy with the potential to promote long-term weight loss maintenance for bariatric surgery patients.

The long-term efficacy of bariatric surgery is not entirely clear, and weight regain and diabetes relapse are problems for some patients. Exercise is a feasible and clinically effective adjunct therapy for bariatric surgery patients. We hypothesize that exercise is also a critical factor for long-term weight loss maintenance and lasting remission of type 2 diabetes.

Effectiveness of exercise training after bariatric surgery-a systematic literature review and meta-analysis

We aimed to conduct a systematic review and meta-analysis of controlled trials assessing exercise training programs in patients with obesity undergoing bariatric surgery. We systematically searched exercise training studies performed after bariatric surgery published up to June 2017. Studies reporting changes in body composition, physical fitness, functional capacity, objectively measured physical activity, quality of life or relevant health outcomes were included. The review protocol is available from PROSPERO (CRD42017069380). Meta-analyses were conducted using random-effects models when data were available from at least five articles. Twenty articles were included, describing 16 exercise training programs, of which 15 were included in the meta-analysis. Overall, exercise training was associated with higher weight loss (mean difference: -2.4 kg, 95% CI: -4.2; -0.6, I²  = 49%, n = 12), higher fat mass loss (-2.7 kg, 95% CI: -4.5; -1.0, I²  = 50%, n = 8) and improved VO₂ max and functional walking (standardized mean difference: 0.86, 95% CI: 0.29; 1.44, I²  = 57%, n = 6; 1.45, 95% CI: 0.32; 2.58, I²  = 89%, n = 6, respectively). Exercise training was not associated with lean body mass changes. In conclusion, exercise training programs performed after bariatric surgery were found effective to optimize weight loss and fat mass loss and to improve physical fitness, although no additional effect on lean body mass loss was found.

Effect of physical exercise on weight loss and physical function following bariatric surgery: a meta-analysis of randomised controlled trials

OBJECTIVES

We performed a meta-analysis of all of the available randomised controlled trials (RCTs) to investigate whether physical exercise contributes to weight loss or physical function improvement in adults receiving bariatric surgery.

METHODS

We searched PubMed, Embase, the Cochrane Library, OVID and the CINAHL up through May 2018. RCTs that assigned adults with obesity to either an exercise training group or a no-exercise group after bariatric surgery were included. The primary outcomes were weight loss and physical function. Study bias was assessed using the Cochrane risk of bias tool, and the quality of evidence was assessed using GRADEpro.

RESULTS

A total of eight studies met the inclusion criteria (n=347 participants). Most of the studies carried a low risk of bias due to randomisation and blinding. Compared with those without exercise intervention after surgery, patients engaging in physical exercise were associated with greater weight loss (weighted mean difference (WMD) -1.94 kg; 95% CI -3.18 to -0.69; n=8) and longer 6 min walk distance (6MWD; WMD29.67 m; 95% CI 25.97 to 33.37; n=2) during follow-up. By subgroup analyses, the additional weight loss in exercise group was related to the starting time and type of exercise: patients engaging in exercise 1 year or more after surgery and patients received aerobic-resistance exercise experienced more weight loss. Besides, patients in exercise training group also had lower systolic blood pressure and resting heart rate after surgery. The quality of evidence for these outcomes was moderate to very low.

CONCLUSIONS

Physical exercise after bariatric surgery provides 1.94 kg additional weight loss and 29.67 m longer 6MWD compared with surgery alone. Moreover, engaging in exercise 1 year or more after surgery, and a combined aerobic and resistance training programme may result in greater weight loss.

Measurement duration affects the calculation of whole body protein turnover kinetics but not between-day variability

BACKGROUND

Assessment of whole body protein turnover (WBPT) can provide fundamental information about protein kinetics which underpins the conservation of lean tissue. Reliability and methodology studies on the measurement of WBPT are scarce. This study aimed to assess the effects of urine collection duration (9 versus 12 h) and the reproducibility of WBPT with the end product method calculated from ammonia as the end product.

METHODS

WBPT was assessed in 21 healthy participants (11M, 10F) on 2 test days. WBPT was assessed using the end product method with a single dose of ¹⁵N glycine with ammonia as end product in a postprandial state with 9 and 12-h urine collections.

RESULTS

The CV for protein flux averaged 10% and 12% for 9 and 12-h urine collections respectively. Protein flux, synthesis and balance were significantly higher and protein breakdown significantly lower with 9-h urine collections compared to 12-h collections (P < 0.01) and there was a trend towards increasingly greater overestimation of 9-h calculated WBPT kinetics with greater overall rates of WBPT. Correlations between the 9 and 12-h values were strong (r > 0.962, P < 0.001 for all variables).

CONCLUSIONS

The reproducibility of WBPT with ammonia as the end product was similar to previously reported reproducibility of the gold standard precursor technique. The use of a 12-h urine collection is more effective to achieve full turnover of the ammonia free amino acid (AA) pool.

Protein synthesis signaling in skeletal muscle is refractory to whey protein ingestion during a severe energy deficit evoked by prolonged exercise and caloric restriction

BACKGROUND

Exercise and protein ingestion preserve muscle mass during moderate energy deficits.

OBJECTIVE

To determine the molecular mechanisms by which exercise and protein ingestion may spare muscle mass during severe energy deficit (5500 kcal/day).

DESIGN

Fifteen overweight, but otherwise healthy men, underwent a pre-test (PRE), caloric restriction (3.2 kcals/kg body weight/day) + exercise (45 min one-arm cranking + 8 h walking) for 4 days (CRE), followed by a control diet (CD) for 3 days, with a caloric content similar to pre-intervention while exercise was reduced to less than 10,000 steps per day. During CRE, participants ingested either whey protein (PRO, n = 8) or sucrose (SU, n = 7) (0.8 g/kg body weight/day). Muscle biopsies were obtained from the trained and untrained deltoid, and vastus lateralis.

RESULTS

Following CRE and CD, serum concentrations of leptin, insulin, and testosterone were reduced, whereas cortisol and the catabolic index (cortisol/total testosterone) increased. The Akt/mTor/p70S6K pathway and total eIF2α were unchanged, while total 4E-BP1 and Thr^37/464E-BP1 were higher. After CRE, plasma BCAA and EAA were elevated, with a greater response in PRO group, and total GSK3β, pSer⁹GSK3β, pSer⁵¹eIF2α, and pSer⁵¹eIF2α/total eIF2α were reduced, with a greater response of pSer⁹GSK3β in the PRO group. The changes in signaling were associated with the changes in leptin, insulin, amino acids, cortisol, cortisol/total testosterone, and lean mass.

CONCLUSIONS

During severe energy deficit, pSer⁹GSK3β levels are reduced and human skeletal muscle becomes refractory to the anabolic effects of whey protein ingestion, regardless of contractile activity. These effects are associated with the changes in lean mass and serum insulin, testosterone, and cortisol concentrations.

Prospective Study on Body Composition, Energy Balance and Biological Factors Changes in Post-menopausal Women with Breast Cancer Receiving Adjuvant Chemotherapy Including Taxanes

In breast cancer patients, weight and fat mass changes observed after chemotherapy have been related to poor prognosis but some recent works using modern chemotherapy failed to find this correlation with weight gain. In this study, the extent of changes in weight and body composition (DEXA, impedance) was characterized until six months after current chemotherapy, in 50 post-menopausal women with breast cancer. The evolution of factors contributing to the energy balance and some biological factors were also described. During chemotherapy, 20% of women lost weight due to both fat (-13.1% ± 10.3) and lean soft tissue mass loss (-3.6% ± 4.6). Twenty percent of women gained weight. No significant fat mass gain was observed in these women but significant water gain was highlighted. Six months later, women who gained weight presented a gain in fat mass (15.4% ± 19.0), especially in the abdominal region. Age and initial BMI were negatively correlated with fat mass in multivariate analyzes (r = 0.486, P = 0.0030). No significant variation of the glucose homeostasis, triglycerides, and HDL-Cholesterol was found six months after chemotherapy. These results do not suggest major adverse metabolic disturbances six months after modern chemotherapy and only a mild fat mass gain was observed in women who gained weight.

A Moderate Interleukin-6 Reduction, Not a Moderate Weight Reduction, Improves the Serum Iron Status in Diet-Induced Weight Loss with Fish Oil Supplementation

BACKGROUND & AIMS

Whether moderate weight loss or a reduction in IL-6 improves the serum iron status in overweight (OW) and obese adults supplemented with or without fish oil is explored.

METHODS AND RESULTS

In total, 93 OW/obese Taiwanese adults with ≥2 metabolic components are randomized to a 12-week calorie-restricted diet with meal replacement alone (CRMR, n = 45) or supplemented with fish oil (CRMRF, n = 48). Mean reductions in the %body weight and serum IL-6 are 7.5% versus 5.9% and 21% versus 35% for the CRMR and CRMRF groups, respectively. In the CRMRF group, a moderate loss of IL-6 (reduced ≥35%) also significantly improves the serum iron and transferrin saturation compared to those with loss of <35% in the mean serum IL-6 or those of the CRMR group who has a moderate loss of IL-6 (reduced ≥21%) (all p < 0.05). In contrast, modest weight loss does not improve the serum iron status.

CONCLUSIONS

Fish oil is ineffective as an adjunct for weight or fat loss but has beneficial effects on preserving the lean body mass. A significant improvement in the iron status is only observed in those with moderate loss of serum IL-6 supplemented with fish oil.

Rationale and Protocol for a Randomized Controlled Trial Comparing Fast versus Slow Weight Loss in Postmenopausal Women with Obesity-The TEMPO Diet Trial

Very low energy diets (VLEDs), commonly achieved by replacing all food with meal replacement products and which result in fast weight loss, are the most effective dietary obesity treatment available. VLEDs are also cheaper to administer than conventional, food-based diets, which result in slow weight loss. Despite being effective and affordable, these diets are underutilized by healthcare professionals, possibly due to concerns about potential adverse effects on body composition and eating disorder behaviors. This paper describes the rationale and detailed protocol for the TEMPO Diet Trial (Type of Energy Manipulation for Promoting optimal metabolic health and body composition in Obesity), in a randomized controlled trial comparing the long-term (3-year) effects of fast versus slow weight loss. One hundred and one post-menopausal women aged 45–65 years with a body mass index of 30–40 kg/m² were randomized to either: (1) 16 weeks of fast weight loss, achieved by a total meal replacement diet, followed by slow weight loss (as for the SLOW intervention) for the remaining time up until 52 weeks (“FAST” intervention), or (2) 52 weeks of slow weight loss, achieved by a conventional, food-based diet (“SLOW” intervention). Parameters of body composition, cardiometabolic health, eating disorder behaviors and psychology, and adaptive responses to energy restriction were measured throughout the 3-year trial.

Fat-Free Mass and Skeletal Muscle Mass Five Years After Bariatric Surgery

OBJECTIVE

This study investigated changes in fat-free mass (FFM) and skeletal muscle 5 years after surgery in participants from the Longitudinal Assessment of Bariatric Surgery-2 trial.

METHODS

A three-compartment model assessed FFM, and whole-body magnetic resonance imaging (MRI) quantified skeletal muscle mass prior to surgery (T0) and 1 year (T1), 2 years (T2), and 5 years (T5) postoperatively in 93 patients (85% female; 68% Caucasian; age 44.2 ± 11.6 years) who underwent gastric bypass (RYGB), sleeve gastrectomy, or adjustable gastric band. Repeated-measures mixed models were used to analyze the data.

RESULTS

Significant weight loss occurred across all surgical groups in females from T0 to T1. FFM loss from T0 to T1 was greater after RYGB (mean ± SE: -6.9 ± 0.6 kg) than adjustable gastric band (-3.5 ± 1.4 kg; P < 0.05). Females with RYGB continued to lose FFM (-3.3 ± 0.7 kg; P < 0.001) from T1 to T5. A subset of males and females with RYGB and MRI-measured skeletal muscle showed similar initial FFM loss while maintaining FFM and skeletal muscle from T1 to T5.

CONCLUSIONS

Between 1 and 5 years following common bariatric procedures, FFM and skeletal muscle are maintained or decrease minimally. The changes observed in FFM and muscle during the follow-up phase may be consistent with aging.

Meta-analysis of the effect of bariatric surgery on physical function

BACKGROUND

Obesity leads to an impairment of physical function that limits the ability to perform basic physical activities affecting quality of life. Literature on the effect of bariatric surgery on physical function is confounding and generally of low quality.

METHODS

A comprehensive search was undertaken using MEDLINE, Scopus (including Embase), CENTRAL, PubMed, SPORTDiscus, Scirus and OpenGrey for published research and non-published studies to 31 March 2017. Studies employing objective measurement and self-reporting of physical function before and after bariatric surgery were included. The magnitude of experimental effect was calculated in terms of the standardized mean difference (MD), and confidence intervals were set at 95 per cent to reflect a significance level of 0·05.

RESULTS

Thirty studies including 1779 patients met the inclusion criteria. Physical function improved after bariatric surgery at 0-6 months (MD 0·90, 95 per cent c.i. 0·60 to 1·21; P < 0·001), more than 6 to 12 months (MD 1·06, 0·76 to 1·35; P < 0·001) and more than 12 to 36 months (MD 1·30, 1·07 to 1·52; P < 0·001). Objective assessment of physical function after bariatric surgery showed improvement at 0-6 months (MD 0·94, 0·57 to 1·32; P < 0·001), more than 6 to 12 months (MD 0·77, 0·15 to 1·40; P = 0·02) and more than 12 to 36 months (MD 1·04, 0·40 to 1·68; P = 0·001). Self-reported assessment of physical function showed similar improvements at 0-6 months (MD 0·80, 0·12 to 1·47; P = 0·02), more than 6 to 12 months (MD 1·42, 1·23 to 1·60; P < 0·001) and more than 12 to 36 months (MD 1·41, 1·20 to 1·61; P < 0·001) after a bariatric procedure.

CONCLUSION

Bariatric surgery improves physical function significantly within 6 months of the procedure and this effect persists over time to 36 months after surgery, whether measured objectively or by self-reporting.

Satiety and gastrointestinal hormones during a Mixed Meal Tolerance Test after gastric bypass surgery: association with plasma amino acid concentrations

BACKGROUND

Circulating amino acids have been associated with both appetite and the secretion of anorexigenic hormones in healthy and obese populations. This effect has not been investigated in subjects having undergone Roux-en-Y gastric bypass surgery (RYGB).

OBJECTIVE

To investigate the association between postprandial plasma concentrations of amino acids and the anorexigenic hormones glucagon-like peptide-1 (GLP-1) and peptide tyrosine tyrosine (PYY), the orexigenic hormone ghrelin, and satiety and hunger in post-RYGB subjects.

SETTING

A Dutch surgical department.

METHODS

Participants after primary RYGB were studied during a Mixed Meal Tolerance Test (MMTT). Satiety and hunger were assessed every 30 minutes on visual analogue scales. Blood samples were collected at baseline, every 10 minutes during the first half hour and every 30 minutes until 210 minutes after the start. The samples were assessed for 24 amino acids and 3 gastrointestinal hormones. Incremental areas under the curve (iAUCs) were calculated. Exploratory analyses were performed in which subjects were divided into high and low responders depending on the median iAUC.

RESULTS

42 subjects, aged 48 ± 11 (mean ± SD) years, 31 to 76 months post-RYGB and with total weight loss of 30 ± 9% completed the MMTT. Subjects with high satiety scores had more than a 25% higher net iAUC of PYY and GLP-1 and at least a 10% higher net iAUC of 10 amino acids compared to subjects with low scores (P < 0.05). The net iAUC of five of these amino acids (i.e. arginine, asparagine, histidine, serine and threonine) was more than 10% higher in subjects with high responses on GLP-1 and/or PYY (P < 0.05).

CONCLUSIONS

Certain postprandial amino acids were associated with satiety and anorexigenic hormones and could therefore play a role in appetite regulation after RYGB; either by a direct effect on satiety, indirectly through gastrointestinal hormones, or both.

Predictive score of sarcopenia occurrence one year after bariatric surgery in severely obese patients

Background and aim

Sarcopenic obesity is a risk factor of morbidity and mortality. The aim of this study was to generate a predictive score of sarcopenia occurrence one year after bariatric surgery.

Patients and methods

We conducted an observational prospective cohort study on a total of 184 severely obese patients admitted to our institution to undergo sleeve gastrectomy. Skeletal muscle cross-sectional area at the third lumbar vertebrae (SMA, cm²) was measured from the routinely performed computed tomography. The skeletal muscle index (SMI) was calculated as follows: SMA/height² (cm²/m²). Sarcopenia was defined as an SMI < 38.5 cm²/m² for women and < 52.4 cm²/m² for men. Measurements were performed at surgery and one year later.

Results

Most of the included patients were female (79%), with a mean age of 42±0.9 years and body mass index of 43.2±0.5 kg/m². Fifteen patients (8%) had sarcopenia before surgery and 59 (32%) at the one-year follow-up. Male gender (p<0.0001), SMA before surgery (p<0.0001), and SMI before surgery (p<0.0001) significantly correlated with the occurrence of sarcopenia one year after surgery by multivariate analysis. Two predictive sarcopenia occurrence scores were constructed using SMA and gender (SS1 score) or SMI and gender (SS2 score). The area under receiver operating characteristic (AUROC) curve of the SS2 score was significantly greater than that of the SS1 score for the diagnosis of postoperative sarcopenia occurrence (0.95±0.02 versus 0.90±0.02; p<0.01). A cut-off value for the SS2 score of 0.53 had a sensitivity of 90%, a specificity of 91%, a positive predictive value of 83%, and a negative predictive value of 95%. In the group of patients without baseline sarcopenia, the SS2 score had still an excellent AUROC of 0.92±0.02. A cut-off of 0.55 predicted development of sarcopenia one year after sleeve gastrectomy in these patients with a sensitivity of 87%, a specificity of 88%, and negative predictive value of 95%.

Conclusion

The SS2 score has excellent predictive value for the occurrence of sarcopenia one year after sleeve gastrectomy. This score can be used to target early intensification of nutritional and dietetic follow-up to the predicted high-risk population.

Sarcopenic obesity: Time to meet the challenge

The prevalence of overweight and obesity has reached epidemic proportions worldwide due to increasingly pervasive obesogenic lifestyle changes. Obesity poses unprecedented individual, social and multi-disciplinary medical challenges by increasing the risk for metabolic diseases, chronic organ failures and cancer, as well as complication rates in the presence of acute disease conditions. Whereas reducing excess adiposity remains the fundamental pathogenetic treatment for obese individuals, complex metabolic and lifestyle abnormalities as well as weight-reduction therapies per se may also compromise the ability to preserve muscle function and mass, especially when chronic disease co-exists with obesity. Emerging evidence indicates that low muscle mass and quality have a strong negative prognostic impact in obese individuals and may lead to frailty, disability and increased morbidity and mortality. Awareness of the importance of skeletal muscle maintenance in obesity is however low among clinicians and scientists. The term "sarcopenic obesity" has been proposed to identify obesity with low skeletal muscle function and mass, but its utilization is largely limited to the aging patient population, and consensus on its definition and diagnostic criteria remains insufficient. Knowledge on prevalence of sarcopenic obesity in various clinical conditions and patient subgroups, on its clinical impacts in patient risk stratification and on effective prevention and treatment strategies remain therefore dramatically inadequate. In particular, optimal dietary options and medical nutritional support strategies to preserve muscle mass in obese individuals remain largely undefined. The European Society for Clinical Nutrition and Metabolism (ESPEN) and the European Association for the Study of Obesity (EASO) recognize and indicate obesity with altered body composition due to low skeletal muscle function and mass (sarcopenic obesity) as a scientific and clinical priority for researchers and clinicians. ESPEN and EASO therefore call for coordinated action aimed at reaching consensus on its definition, diagnostic criteria and optimal treatment with particular regard to nutritional therapy. We are convinced that achievement of these goals has strong potential to reduce the burden of morbidity and mortality in the rapidly increasing obese patient population.

Composition of two-week change in body weight under unrestricted free-living conditions

The composition of weight change has a large impact on energy balance calculations. Composition of long-term weight change interventions is well-documented, but information on short-term weight change under unrestricted free-living conditions is limited. The composition and energy density of the changes in body weight during 2-week free-living conditions were analyzed in adults from two cohorts: cohort 1 (n = 24) included participants from the reproducibility subset of the Observing Protein and Energy Nutrition study; cohort 2 (n = 22) included participants who were studied under free-living conditions in an ongoing study in the Chicago area. Change in body weight, total body water (TBW) by stable isotope dilution (cohort 1), and fat mass (FM) and fat-free mass (FFM) by serial DXA (cohort 2) were measured. To determine the fractional composition of the change in body weight we analyzed the linear associations between changes in body weight and changes in body composition. In the combined dataset, the average change in body weight (0.26 ± 1.2 kg) was consistent with being in energy balance. Average change in body weight was associated with the change in TBW (P < 0.0001) in cohort 1 and the change in FFM (P = 0.0002) in cohort 2. A unit change in body weight was composed of 84% change in FFM in the combined dataset indicating that 2-week fluctuation in body weight is largely composed of FFM The energy density of 1-3 kg short-term changes in body weight averaged 2380 kcal/kg.

The importance of specific rehabilitation for an obese patient with idiopathic intracranial hypertension: a case report

Idiopathic intracranial hypertension (IIH) is associated with obesity, and weight loss is important to reduce intracranial pressure and improve visual function. A 38-year-old woman with IIH followed an extreme diet, which resulted in 30% weight loss (BMI moved from 34.9 to 24.6). Weight loss resulted in a significant reduction of papilloedema, normalization of intracranial pressure and improvement in headache pattern, but also induced a state of initial malnutrition, relevant depression and disability. She was discharged with the indication to start a controlled diet and improve physical activity: clinical situation get back to stability, with the patient loosing further weight (BMI=21.8) through a balanced diet and moderate physical exercise. Obese patients with IIH should be offered a comprehensive treatment approach consisting of diet and nutritional support, psychological counselling, indication to increase physical activity and, when appropriate, a specific rehabilitation programme.

Preserved Fat-Free Mass after Gastric Bypass and Duodenal Switch

Background

Concerns for the possibility of an excessive loss of fat-free mass (FFM) and resting metabolic rate (RMR) after bariatric surgery, such as Roux-en-Y gastric bypass (RYGB) and duodenal switch (BPD/DS), have been raised.

Objectives

This study aims to examine body composition and RMR in patients after RYGB and BPD/DS and in non-operated controls.

Methods

Body composition and RMR were studied with Bod Pod and indirect calorimetry in weight-stable RYGB (n = 15) and BPD/DS patients (n = 12) and compared with non-operated controls (n = 17). All patients were 30–55 years old and weight stable with BMI 28–35 kg/m².

Results

FFM% was 58% (RYGB), 61% (BPD/DS), and 58% (controls). Body composition did not differ after RYGB and BPD/DS compared to controls, despite 27 and 40% total body weight loss, respectively. No difference in RMR or RMR/FFM was observed (1539, 1617, and 1490 kcal/24 h; and 28.9, 28.4, and 28.8 kcal/24 h/kg).

Conclusion

Weight-stable patients with BMI 28–35 kg/m² after RYGB and BPD/DS have a body composition and RMR similar to that of non-operated individuals within the same BMI interval.

Severe negative energy balance during 21 d at high altitude decreases fat-free mass regardless of dietary protein intake: a randomized controlled trial

In this 2-phase randomized controlled study, we examined whether consuming a higher-protein (HP) diet would attenuate fat-free mass (FFM) loss during energy deficit (ED) at high altitude (HA) in 17 healthy males (mean ± sd: 23 ± 6 yr; 82 ± 14 kg). During phase 1 at sea level (SL, 55 m), participants consumed a eucaloric diet providing standard protein (SP; 1.0 g protein/kg,) for 21 d. During phase 2, participants resided at HA (4300 m) for 22 d and were randomly assigned to either an SP or HP (2.0 g protein/kg) diet designed to elicit a 40% ED. Body composition, substrate oxidation, and postabsorptive whole-body protein kinetics were measured. Participants were weight stable during SL and lost 7.9 ± 1.9 kg ( P < 0.01) during HA, regardless of dietary protein intake. Decrements in whole-body FFM (3.6 ± 2.4 kg) and fat mass (3.6 ± 1.3 kg) were not different between SP and HP. HP oxidized 0.95 ± 0.32 g protein/kg per day more than SP and whole-body net protein balance was more negative for HP than for SP ( P < 0.01). Based on changes in body energy stores, the overall ED was 70% (-1849 ± 511 kcal/d, no group differences). Consuming an HP diet did not protect FFM during severe ED at HA.-Berryman, C. E., Young, A. J., Karl, J. P., Kenefick, R. W., Margolis, L. M., Cole, R. E., Carbone, J. W., Lieberman, H. R., Kim, I.-Y., Ferrando, A. A., Pasiakos, S. M. Severe negative energy balance during 21 d at high altitude decreases fat-free mass regardless of dietary protein intake: a randomized controlled trial.

Influence of gastric bypass surgery on resting energy expenditure, body composition, physical activity, and thyroid hormones in morbidly obese patients

INTRODUCTION

One way to lose weight is bariatric surgery. Various studies have shown that after Roux-en-Y gastric bypass (RYGB), resting energy expenditure (REE) decreased may be a result of changes in fat-free mass (FFM) and thyroid-stimulating hormone levels. The aim of our study was to assess changes in body composition, REE, and thyroid hormones in patients undergoing RYGB.

METHODS

A total of 42 patients participated (21 undergoing RYGB and 21 age- and weight-matched subjects as controls) in our study. Weight, body-mass index, body composition, resting metabolic rate, physical activity, and thyroid hormones were measured at baseline in cases and 3 months after surgery in case and control groups.

RESULTS

At 3 months after surgery, patients lost an average of 21.7±1.4 kg weight, and fat mass, FFM, and REE decreased significantly. REE was higher in cases compared to controls. T₄, T₃, and thyroid-stimulating hormone at 3 months after RYGB decreased, but the decrease was significant only in T₄ compared to controls. FFM was higher and fat mass lower in cases compared to controls.

CONCLUSION

We detected a meaningful difference in REE before and after surgery, but we did not detect any meaningful difference in REE between controls and cases.

Sarcopenic Obesity: Time to Meet the Challenge

The prevalence of overweight and obesity has reached epidemic proportions worldwide due to increasingly pervasive obesogenic lifestyle changes. Obesity poses unprecedented individual, social, and multidisciplinary medical challenges by increasing the risk for metabolic diseases, chronic organ failures, and cancer as well as complication rates in the presence of acute disease conditions. Whereas reducing excess adiposity remains the fundamental pathogenic treatment for obese individuals, complex metabolic and lifestyle abnormalities as well as weight reduction therapies per se may also compromise the ability to preserve muscle function and mass, especially when chronic disease co-exists with obesity. Emerging evidence indicates that low muscle mass and quality have a strong negative prognostic impact in obese individuals and may lead to frailty, disability, and increased morbidity and mortality. Awareness of the importance of skeletal muscle maintenance in obesity is however low among clinicians and scientists. The term 'sarcopenic obesity' has been proposed to identify obesity with low skeletal muscle function and mass, but its utilization is largely limited to the aging patient population, and consensus on its definition and diagnostic criteria remains insufficient. Knowledge on prevalence of sarcopenic obesity in various clinical conditions and patient subgroups, on its clinical impacts in patient risk stratification, and on effective prevention and treatment strategies remain therefore dramatically inadequate. In particular, optimal dietary options and medical nutritional support strategies to preserve muscle mass in obese individuals remain largely undefined. The European Society for Clinical Nutrition and Metabolism (ESPEN) and the European Association for the Study of Obesity (EASO) recognize and indicate obesity with altered body composition due to low skeletal muscle function and mass (sarcopenic obesity) as a scientific and clinical priority for researchers and clinicians. ESPEN and EASO therefore call for coordinated action aimed at reaching consensus on its definition, diagnostic criteria, and optimal treatment with particular regard to nutritional therapy. We are convinced that achievement of these goals has a strong potential to reduce the burden of morbidity and mortality in the rapidly increasing obese patient population.

Resistance training during a 12-week protein supplemented VLCD treatment enhances weight-loss outcomes in obese patients

BACKGROUND

This investigation evaluated the efficacy by which resistance training enhances body composition, metabolic, and functional outcomes for obese patients undergoing a 12-week medically supervised hypocaloric treatment.

METHODS

This was a single-blind, randomized, parallel-group prospective trial. Morbidly obese patients were prescribed a 12-week proprietary very low calorie diet (VLCD) treatment (Optifast^®) with supplemental protein (1120 kcals/day) and were placed in one of two groups for 14 weeks: 1) Standard Treatment Control (CON) (n = 5) or 2) Resistance Training (RT) (n = 6). Both groups underwent a pedometer-based walking program; however only RT performed resistance training 3 days/week for 12 weeks. Body composition, resting energy expenditure (REE), neuromuscular function, and serum biomarkers were measured at weeks 0, 6, and 13.

RESULTS

Both groups exhibited a significant loss of total body mass (TBM) (CON: -19.4 ± 2.3 kg, p = 0.0009 vs. RT: -15.8 ± 1.5 kg, p = 0.0002) and fat mass (FM) (CON: -14.7 ± 1.8 kg, p = 0.0002 vs. RT: -15.1 ± 2.1 kg, p = 0.0002) with no group differences. CON lost 4.6 ± 0.8 kg (p = 0.004) of lean mass (LM) while RT demonstrated no changes. Group differences were found for the relative proportion of total weight-loss due to FM-loss (CON: 75.6 ± 3.4% vs. RT: 96.0 ± 6.0%, p = 0.03) and LM-loss (CON: 24.4 ± 3.2% vs. RT: 4.0 ± 6.5%, p = 0.03). CON demonstrated a 328.6 ± 72.7 kcal/day (-14.3 ± 2.4%) (p = 0.02) decrease in REE while RT exhibited a non-significant decrease of 4.6 ± 1.6% (p = 0.78). RT demonstrated greater improvements in all measures of contractile function and strength when compared to CON (p < 0.05). At post-treatment, RT exhibited greater serum free fatty acids (p = 0.01), glycerol (p = 0.003), and β-hydroxybutyrate (p = 0.005) than CON.

CONCLUSION

Resistance training was advantageous for weight-loss composition by preservation of LM without compromising overall weight- or fat-loss in morbidly obese men and women undergoing a protein supplemented VLCD. These changes accompanied positive adaptations for resting metabolism and muscular function.

Differences in Body Composition in Patients with Obesity 1 Year After Roux-En-Y Gastric Bypass: Successful Vs. Unsuccessful Weight Loss

AIM

The aim of this study is to compare the differences in body composition in patients with obesity with successful weight loss (SWL) and unsuccessful (USWL) 1 year after Roux-en-Y gastric bypass (RYGB).

METHODS

We included 36 women and 22 men. After stratifying patients according with SWL (defined as ≥ 50% of excess weight loss), fat-free mass (FFM) and fat mass (FM) trajectories were analyzed in each group.

RESULTS

The %FM in SWL women (78%) was lower than USWL (36 vs. 44, p < 0.001). The %FM in SWL men (77%) was lower than USWL (27 vs. 38, p < 0.05). A lower %FM before surgery increased the probability of success (p < 0.05).

CONCLUSIONS

SWL patients have a lower %FM, and those with lower pre-surgical %FM are more likely to have SWL 1 year after RYGB.

Changes in Resting Energy Expenditure in Relation to Body Weight and Composition Following Gastric Restriction: A Systematic Review

In comparison to gastric bypass surgery, gastric restriction without malabsorption more closely simulates dietary adherence while still producing durable weight loss. The latter is achieved despite considerable reductions in resting energy expenditure (REE), and whether REE is adjusted for body weight/composition using ratio- or regression-based methods could influence understanding of how these procedures affect energy balance. This systematic review identified studies that reported REE before and after gastric restriction in order to compare changes using each method. Ratio assessments revealed increases and decreases when REE was expressed per kilogram of body weight and per kilogram of fat-free mass, respectively. In comparison, measured REE tended to be less than predicted from linear regression after surgery. Explanations for these seemingly disparate findings and future directions are discussed.

Effect of Protein Intake on the Protein Status and Lean Mass of Post-Bariatric Surgery Patients: a Systematic Review

BACKGROUND

Post-bariatric surgery may compromise nutritional status due to energy and protein intake restriction.

METHODS

Systematic review was performed to synthesize evidence on the amount of protein intake and its association with lean mass and serum proteins during at least 6 months following Roux-en-Y gastric bypass or sleeve gastrectomy.

RESULTS

Twelve studies (n = 739) were identified in the search. Protein intake below 60 g/day and significant lean mass loss were observed in majority of these studies. Of the four studies that measured association between protein intake and lean mass retention, only two supported this hypothesis.

CONCLUSION

There is insufficient evidence of the effect of dietary protein on serum protein levels. Further studies are needed to better estimate the protein intake that supports a healthy nutritional status in this population.

Relationship Between Bariatric Surgery and Bone Mineral Density: a Meta-analysis

BACKGROUND

A meta-analysis regarding bone loss after bariatric surgery, designed to compare surgical and nonsurgical groups, has not yet been performed. Therefore, we performed a meta-analysis to compare the differences between bariatric surgical groups and nonoperated controls with regard to bone mineral density.

METHODS

In March 2015, we performed a review of the literature using PubMed, EMBASE, and the Cochrane Library. The search focused on retrospective and prospective studies, including but not limited to randomized studies published in English.

RESULTS

Among 1299 studies that were initially screened, ten met the selection criteria. For all types of bariatric surgery, bone density at the femoral neck was lower in the surgical group than in the nonsurgical control group (mean difference [MD] -0.05 g/cm(2); 95 % confidence interval [CI], -0.07 to -0.02; p = 0.001); no difference in bone density was found between the two groups at the lumbar spine (MD -0.01 g/cm(2); 95 % CI -0.07 to 0.05; p = 0.661). The analysis of Roux-en-Y gastric bypass showed similar results.

CONCLUSION

Bone density at the femoral neck decreased after bariatric surgery, compared to that in nonsurgical controls, whereas bone density at the lumbar spine did not show a difference between groups. Further larger scale studies with comparative nonsurgical controls are warranted to overcome the heterogeneity among studies in this analysis and to add evidence of possible bone loss subsequent to bariatric surgical procedures.

Weighted Vest Use during Dietary Weight Loss on Bone Health in Older Adults with Obesity

Background

To examine the effects of daily weighted vest use during a dietary weight loss intervention, on (a) hip and spine bone mineral density (aBMD), and (b) biomarkers of bone turnover, in older adults with obesity.

Methods

37 older (70.1 ± 3.0 years) adults with obesity (BMI=35.3 ± 2.9) underwent a 22 week dietary weight loss intervention (1100–1300 kcal/day) with (Diet+Vest; n=20) or without (Diet; n=17) weighted vest use (goal: 10+ h/day; weight added incrementally based on amount of weight lost). Total body weight; DXA-acquired aBMD of the total hip, femoral neck and lumbar spine; and biomarkers of bone turnover (OC, BALP, P1NP, CTX) were measured at baseline and follow up. General linear models, adjusted for baseline values of the outcome and gender, were used to examine intervention effects.

Results

Average weight loss was significant in both groups (−11.2 ± 4.4 kg and −11.0 ± 6.3 kg, Diet+Vest and Diet groups, respectively), with no difference between groups (p=0.91). Average weighted vest use was 6.7 ± 2.2 h/day. No significant changes in aBMD or biomarkers were observed, although trends were noted for total hip aBMD and BALP. Loss in total hip aBMD was greater in the Diet group compared with Diet+Vest (Δ: −18.7 [29.3, −8.1] mg/cm² versus −6.1 [−15.7, 3.5] mg/cm²; p=0.08). BALP increased in the Diet+Vest group by 3.8% (Δ: 0.59 [−0.33, 1.50] μg/L) and decreased by −4.6% in the Diet group (Δ: −0.70 [−1.70, 0.31] μg/L, p=0.07).

Conclusion

Weighted vest use during weight loss may attenuate loss of hip aBMD and increase bone formation in older adults with obesity. Further study is warranted.

Physical Fitness and Body Composition Two Years after Roux-En-Y Gastric Bypass in Adolescents

BACKGROUND

We have previously shown promising results 2 years after Roux-en-Y gastric bypass surgery, within the Adolescence Morbid Obesity Surgery study (AMOS). The aim of the current study was to describe the 2-year outcome in cardiorespiratory fitness, body composition, and functional capacity in the Stockholm subset of the AMOS study.

METHODS

Forty-one adolescents (10 male, 31 female, age 14-18 years, body mass index 35-69 kg·m^-2) were included. In addition to anthropometric measurements, participants performed a submaximal bicycle test, 6-min walk test, dual-energy X-ray absorptiometry, and a short interview at baseline, 1 and 2 years after surgery.

RESULTS

Relative improvements in maximal oxygen consumption (VO₂max) per kilogram body mass (+62 %) and per kilogram fat-free mass (+21 %), as well as walking distance (+13 %) were observed after 1 year, and persisted 2 years after surgery. Despite a reduction of fat-free mass (-15 %), absolute VO₂max was maintained across the full group (+8 %, p = ns) and significantly increased in non-smokers. Body mass and fat mass were significantly decreased (-45.4 and -33.3 kg, respectively). Self-reported physical activity was significantly increased, and pain associated with movement was reduced.

CONCLUSIONS

In adolescents with obesity, Roux-en-Y gastric bypass improved VO₂max more than could be explained by fat mass loss alone. In combination with improved functional capacity and body composition, these results suggest that surgery in adolescence might add specific benefits of importance for future health.

A Comparative Study Examining the Impact of a Protein-Enriched Vs Normal Protein Postoperative Diet on Body Composition and Resting Metabolic Rate in Obese Patients after Sleeve Gastrectomy

BACKGROUND

We recently showed that an 8-week preoperative protein-enriched diet (PED) is associated with significant reductions in body weight and fat mass (FM) without significant loss of fat-free mass (FFM) in morbidly obese patients scheduled for laparoscopic sleeve gastrectomy (LSG).

OBJECTIVES

The objective of this study is to evaluate the impact of PED vs a normal protein diet (NPD) on total weight loss (TWL), FM, FFM, and resting metabolic rate (RMR) in patients after LSG.

METHODS

Before LSG and at 3, 6, and 12 months after, we prospectively measured and compared total body weight (TBW), FM, FFM, and RMR in 60 male patients who received either a NPD (n = 30) with protein intake 1.0 g/kg of ideal body weight, or a PED (n = 30) with protein intake 2.0 g/kg of ideal body weight. Compliance in following the prescribed diet was determined with food frequency questionnaires in all patients. The impact of NPD and PED on renal function was also evaluated.

RESULTS

Despite non-significant variation in total body weight (TBW), FM decreased more significantly (p < 0.01) with the PED compared to the NPD. In addition, the PED group showed a significantly (p < 0.01) lower decrease in FFM and RMR when compared with the NPD group. Both groups showed high compliance in following the prescribed diets, without negative impact on renal function.

CONCLUSION

PED is more effective than NPD in determining FM loss and is associated with a lower decrease in FFM and RMR, without interfering with renal function in male patients after LSG.

The Phase Angle of the Bioelectrical Impedance Analysis as Predictor of Post-Bariatric Weight Loss Outcome

BACKGROUND

Bariatric surgery is proven to be the most effective therapy for obesity. However, the targeted weight reduction is not always achieved. Reliable predictors for postoperative success are rare. Also, most available predictors, such as gender and socioeconomic status, cannot be influenced. The aim of the study was to assess the reliability of the phase angle (PhA) as a predictor of weight reduction and body composition after bariatric surgery.

METHODS

One hundred seventy-three patients (127 with Roux-en-Y gastric bypass and 46 with sleeve gastrectomy), treated between January 2004 and December 2012, were included into this prospective trial. Bioelectrical impedance analysis (BIA) was performed before and five times within the first year after the operation. Correlation between excess weight loss (EWL) was calculated using Pearson's correlation coefficient and a receiver operating characteristic (ROC) curve.

RESULTS

The average weight loss was significant with a total weight loss of 30.1 %, while the PhA did not show any significant decrease during the first 12 months after surgery. The correlation between the preoperative PhA and the postoperative EWL was significant after 6 weeks and after 6, 9, and 12 months. The ROC curve has an area of 0.7. The best point of the curve is a PhA of 3.9° with a sensitivity of 81 % and a specificity of 54 %.

CONCLUSIONS

PhA may be a useful predictor of EWL after bariatric surgery, and a PhA of 3.9° was calculated as the most suitable cut-off for a successful operation.

Effect of Exercise Type During Intentional Weight Loss on Body Composition in Older Adults with Obesity

OBJECTIVE

To examine the long-term effects of exercise modality during weight loss on body composition and associations between body composition and physical function changes.

METHODS

Two hundred forty-nine older adults (66.9 ± 4.7 years, 71% women, 32% African American, BMI: 34.4 ± 3.7 kg/m² ) were randomized to weight loss (WL; n = 82), WL plus aerobic training (WL + AT; n = 86), or WL plus resistance training (WL + RT; n = 81) for 18 months. Dual-energy x-ray absorptiometry-acquired body composition, 400-m walk time, and knee extensor strength were measured at baseline and at 6 and 18 months.

RESULTS

Total body mass loss was enhanced when WL was combined with exercise (WL: -5.7 ± 0.7 kg, WL + AT: -8.5 ± 0.7 kg, WL + RT: -8.7 ± 0.7 kg; P < 0.01). Total body fat mass loss was significantly greater in WL + AT (-6.8 ± 0.6 kg, -16.4%) and WL + RT (-7.8 ± 0.5 kg, -19.0%) than WL (-4.8 ± 0.6 kg, -10.9%); both P < 0.01. Lean mass loss was greatest in WL + AT (-1.6 ± 0.3 kg, -3.1%) compared with WL + RT (-0.8 ± 0.3 kg, -1.5%) or WL (-1.0 ± 0.3 kg; -2.0%); both P ≤ 0.02. Change in 400-m walk time was associated with change in fat mass (β/SD = +6.1 s; P < 0.01), while change in knee extensor strength was associated with change in lean mass (β/SD = +1.6 Nm; P < 0.01).

CONCLUSIONS

WL + RT results in less lean mass lost than WL + AT; WL plus exercise yields greater fat mass loss than WL alone.

Dietary Magnesium May Be Protective for Aging of Bone and Skeletal Muscle in Middle and Younger Older Age Men and Women: Cross-Sectional Findings from the UK Biobank Cohort

Although fragility fractures, osteoporosis, sarcopenia, and frailty are becoming more prevalent in our aging society the treatment options are limited and preventative strategies are needed. Despite magnesium being integral to bone and muscle physiology, the relationship between dietary magnesium and skeletal muscle and bone health has not been investigated concurrently to date. We analysed cross-sectional associations between dietary magnesium and skeletal muscle mass (as fat free mass-FFM), grip strength, and bone density (BMD) in 156,575 men and women aged 39-72 years from the UK Biobank cohort. FFM was measured with bioelectrical impedance and was expressed as the percentage of body weight (FFM%) or as divided by body mass index (FFMBMI). Adjusted mean grip strength, FFM%, FFMBMI, and BMD were calculated according to quintiles of dietary magnesium, while correcting for covariates. Significant inter-quintile differences across intakes of magnesium existed in men and women, respectively, of 1.1% and 2.4% for grip strength, 3.0% and 3.6% for FFM%, 5.1% and 5.5% for FFMBMI, and 2.9% and 0.9% for BMD. These associations are as great or greater than annual measured losses of these musculoskeletal outcomes, indicating potential clinical significance. Our study suggests that dietary magnesium may play a role in musculoskeletal health and has relevance for population prevention strategies for sarcopenia, osteoporosis, and fractures.

Indicator for Success of Obesity Reduction Programs in Adolescents: Body Composition or Body Mass Index? Evaluating a School-based Health Promotion Project after 12 Weeks of Intervention

Background:

Obesity in adolescence is the strongest risk factor for obesity in adulthood. This study aimed to evaluate the effects of a comprehensive lifestyle intervention on different anthropometric indices in 12–16-year-old boy adolescents after 12 Weeks of Intervention.

Methods:

A total of 96 male adolescents from two schools participated in this study. The schools were randomly assigned to intervention (53 students) and control school (43 students). Height and weight of students were measured and their body mass index (BMI) was calculated. Body fat percent (BF) and body muscle percent (BM) was assessed using a bioimpedance analyzer considering the age, gender, and height of students at baseline and after intervention. The obesity reduction intervention was implemented in the intervention school based on the Ottawa charter for health promotion.

Results:

Twelve weeks of intervention decreased BF percent in the intervention group in comparison with the control group (decreased by 1.81% in the intervention group and increased by 0.39% in the control group, P < 0.01). However, weight, BMI, and BM did not change significantly.

Conclusions:

The result of this study showed that a comprehensive lifestyle intervention decreased the body fat percent in obese adolescents, although these changes was not reflected in the BMI. It is possible that BMI is not a good indicator in assessment of the success of obesity management intervention.

Factors Associated with Visceral Fat Loss in Response to a Multifaceted Weight Loss Intervention

Background

Visceral adipose tissue is more metabolically active than other fat depots and is more closely associated with obesity-related diseases, such as cardiovascular disease and type 2 diabetes, than indicators of obesity, such as body mass index. Across various strategies to promote weight loss, including energy-reduced diet and exercise, variable effects on VAT compared to loss of total body fat have been reported.

Methods

To examine the effect of a behavioral weight loss intervention using portion-controlled prepackaged entrées on VAT, we examined data and measurements from overweight/obese men and women (N=183) who were assigned to a weight loss intervention and prescribed a reduced-energy diet with either portion-controlled prepackaged entrées or self-selected meals in a randomized clinical trial. VAT was estimated with dual-energy X-ray absorptiometry at baseline and study end (12 weeks).

Results

VAT loss was greater for the prepackaged entrees group (p=0.02), with an average loss of 29% compared to an average loss of 19% among participants consuming self-selected meals. VAT (mean [SEM]) was 1651 (71) g and 1546 (157) g at baseline and 1234 (59) g and 1278 (118) g at study end in the prepackaged entrees and self-selected meal groups, respectively. Greater VAT loss was associated with higher baseline weight and VAT, and greater weight loss, but not associated with age or physical activity.

Conclusion

Prescribing portion-controlled prepackaged entrees in a behavioral weight loss intervention promotes a reduction in VAT, which should promote improved metabolic profile and reduced cardiovascular disease risk.

Exercise Preserves Lean Mass and Performance during Severe Energy Deficit: The Role of Exercise Volume and Dietary Protein Content

The loss of fat-free mass (FFM) caused by very-low-calorie diets (VLCD) can be attenuated by exercise. The aim of this study was to determine the role played by exercise and dietary protein content in preserving the lean mass and performance of exercised and non-exercised muscles, during a short period of extreme energy deficit (~23 MJ deficit/day). Fifteen overweight men underwent three consecutive experimental phases: baseline assessment (PRE), followed by 4 days of caloric restriction and exercise (CRE) and then 3 days on a control diet combined with reduced exercise (CD). During CRE, the participants ingested a VLCD and performed 45 min of one-arm cranking followed by 8 h walking each day. The VLCD consisted of 0.8 g/kg body weight/day of either whey protein (PRO, n = 8) or sucrose (SU, n = 7). FFM was reduced after CRE (P < 0.001), with the legs and the exercised arm losing proportionally less FFM than the control arm [57% (P < 0.05) and 29% (P = 0.05), respectively]. Performance during leg pedaling, as reflected by the peak oxygen uptake and power output (Wpeak), was reduced after CRE by 15 and 12%, respectively (P < 0.05), and recovered only partially after CD. The deterioration of cycling performance was more pronounced in the whey protein than sucrose group (P < 0.05). Wpeak during arm cranking was unchanged in the control arm, but improved in the contralateral arm by arm cranking. There was a linear relationship between the reduction in whole-body FFM between PRE and CRE and the changes in the cortisol/free testosterone ratio (C/FT), serum isoleucine, leucine, tryptophan, valine, BCAA, and EAA (r = −0.54 to −0.71, respectively, P < 0.05). C/FT tended to be higher in the PRO than the SU group following CRE (P = 0.06). In conclusion, concomitant low-intensity exercise such as walking or arm cranking even during an extreme energy deficit results in remarkable preservation of lean mass. The intake of proteins alone may be associated with greater cortisol/free testosterone ratio and is not better than the ingestion of only carbohydrates for preserving FFM and muscle performance in interventions of short duration.

Effect of a randomised 12-week resistance training programme on muscular strength, cross-sectional area and muscle quality in women having undergone Roux-en-Y gastric bypass

The purpose of this study was to examine the effect of a 12-week resistance training programme on fat-free mass (FFM), muscle cross-sectional area, muscular strength and muscle quality in women who underwent Roux-en-Y gastric bypass surgery. Participants were 16 women (mean age = 44.9 ± 10.2 years) from bariatric surgical groups who were randomly assigned into either a control or an intervention group. Air displacement plethysmography measured FFM and magnetic resonance imaging measured quadriceps muscle cross-sectional area and whole thigh muscle cross-sectional area. Muscular strength and quality was assessed using an estimated 1-Repetition Maximum assessment. All measurements were collected twice, at baseline and at a 12-week follow-up. There were significantly greater improvements in leg press strength (mean differences = 55.4%, P < 0.001, Cohen's d = 2.4), leg extension strength (mean differences = 18.0%, P = 0.014, Cohen's d = 0.86) and leg press muscle quality (mean differences = 54.5%, P < 0.001, Cohen's d = 1.9) in the intervention group compared to the control group following the resistance training programme. The resistance training intervention significantly improved muscular strength and quality; however, it did not illicit changes in FFM or muscle cross-sectional area in women who underwent Roux-en-Y gastric bypass surgery.

The impact of rate of weight loss on body composition and compensatory mechanisms during weight reduction: A randomized control trial

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).

Effects of an Ad Libitum Consumed Low-Fat Plant-Based Diet Supplemented with Plant-Based Meal Replacements on Body Composition Indices

Objective. To document the effect of a diet free from animal-sourced nutrients on body composition indices. Methods. This was a nonrandomized interventional (n = 241)-control (n = 84) trial with a 10-week, low-fat, plant-based diet supplemented with two daily meal replacements. The meals were allowed to be eaten to full satiety without prespecified calorie restrictions. Control subjects received weekly lectures on the rationale and expected benefits of plant-based nutrition. Body composition indices were measured with bioimpedance analysis. Results. Relative to controls, in cases, postintervention body fat percentage was reduced by 4.3 (95% CI 4.1–4.6)% points (a relative decrement of −13.4%), visceral fat by 1.6 (95% CI 1.5–1.7) fat cross-sectional surface units, and weight by 5.6 kg (95% CI 5.2–6), while muscle mass was reduced by 0.3 kg (95% CI 0.06–0.5) with a relative increase of muscle mass percentage of 4.2 (3.9–4.4)% points. Analysis of covariance showed significantly larger adjusted fat reductions in cases compared to controls. Late follow-up revealed further weight loss in 60% of cases and no significant change in controls. Conclusions. Low-fat, plant-based diet in free-living nonresidential conditions eaten ad libitum enables significant and meaningful body fat reductions with relative preservation of muscle mass. This trial is registered with NCT02906072, ClinicalTrials.gov.