Changes in body composition over 8 years in a randomized trial of a lifestyle intervention: the look AHEAD study

Impact of Simulated Caloric Reduction on Nutrient Adequacy Among United States Adults with Overweight or Obesity (National Health and Nutrition Examination Survey [NHANES] 2015-2018)

BACKGROUND

Current guidelines for the treatment of obesity recommend dietary restriction to create a caloric deficit, and caloric reductions of 16% to 68% have been achieved in adults with overweight or obesity engaging in intentional weight loss programs.

OBJECTIVES

This study models the impact of simulated caloric reduction on nutrient adequacy among United States adults ≥19 y with overweight or obesity using National Health and Nutrition Examination Survey data (2015-2018).

METHODS

Four levels of caloric reduction (20%, 30%, 40%, and 50%) were modeled by prorating daily calorie intake such that usual intakes of 14 nutrients were reduced proportional to caloric reduction. The percentages below the estimated average requirement (EAR) or above the adequate intake (AI) were estimated at each level of caloric reduction, with and without dietary supplement use. Differences across percentages of simulated caloric reductions were determined using nonoverlapping confidence intervals of the means (97.5th percentile confidence intervals were used to approximate P < 0.05).

RESULTS

There were significant differences (P < 0.05) in percentages below the EAR (above the AI) between sequential levels of simulated caloric reduction for most of the nutrients analyzed (protein, vitamins A, B-6, folate, and C, calcium, iron, magnesium, potassium, and zinc). For example, after a simulated 30% caloric reduction, 25%-40% of the population had intakes below the EAR for protein, vitamin B-6, and zinc, and 75%-91% of the population had intakes below the EAR for vitamin A, calcium and magnesium (vs. 4%-18% and 45%-56%, respectively, without caloric reduction). With the inclusion of dietary supplements, percentages below the EAR for all nutrients (except protein) were lower than those for food alone.

CONCLUSIONS

Caloric reduction may exacerbate nutrient inadequacies among adults with overweight or obesity. Inclusion of nutrient-dense foods, fortified foods, specially formulated products, and/or dietary supplements should be considered for those on calorie-restricted diets for long-term weight loss.

Long-term Changes in Body Composition and Exercise Capacity Following Calorie Restriction and Exercise Training in Older Patients with Obesity and Heart Failure With Preserved Ejection Fraction

BACKGROUND

Obesity combined with heart failure with preserved ejection fraction (HFpEF) is the dominant form of HF among older persons. In a randomized trial, we previously showed that a 5-month calorie restriction (CR) program, with or without aerobic exercise training (AT), resulted in significant weight and fat loss and improved exercise capacity. However, little is known regarding the long-term effects of these outcomes after a short-term (5-month) intervention of CR with or without AT in older patients with obesity and HFpEF.

METHODS

Sixteen participants from either the CR or CR+AT who experienced significant weight loss ≥ 2 kg were reexamined after a long-term follow-up endpoint (28.0 ± 10.8 months) without intervention. The follow-up assessment included body weight and composition via dual-energy X-ray absorptiometry and exhaustive cardiopulmonary treadmill exercise testing.

RESULTS

Compared to the 5-month time-point intervention endpoint, at the long-term follow-up endpoint, mean body weight increased +5.2 ± 4.0 kg (90.7 ± 11.2 kg vs 95.9 ± 11.9; P < 0.001) due to increased fat mass (38.9 ± 9.3 vs 43.8 ± 9.8; P < 0.001) with no change in lean mass (49.6 ± 7.1 vs 49.9±7.6; P = 0.67), resulting in worse body composition (decreased lean-to-fat mass). Change in total mass was strongly and significantly correlated with change in fat mass (r = 0.75; P < 0.001), whereas there appeared to be a weaker correlation with change in lean mass (r = 0.50; P = 0.051). Additionally, from the end of the 5-month time-point intervention endpoint to the long-term follow-up endpoint, there were large, significant decreases in VO2peak (-2.2 ± 2.1 mL/kg/min; P = 0.003) and exercise time (-2.4 ± 2.6 min; P = 0.006). There appeared to be an inverse correlation between the change in VO2peak and the change in fat mass (r = -0.52; P = 0.062).

CONCLUSION

Although CR and CR+AT in older patients with obesity and HFpEF can improve body composition and exercise capacity significantly, these positive changes diminish considerably during long-term follow-up endpoints, and regained weight is predominantly adipose, resulting in worsened overall body composition compared to baseline. This suggests a need for long-term adherence strategies to prevent weight regain and maintain improvements in body composition and exercise capacity following CR in older patients with obesity and HFpEF.

Long-term sustained effects of the Look AHEAD lifestyle intervention on body composition among adults with type 2 diabetes

OBJECTIVE

The objective of the study was to test whether there are sustained effects of the Look AHEAD intensive lifestyle intervention (ILI), versus diabetes support and education (DSE), on weight and body composition 12 to 16 years after randomization.

METHODS

Participants were a subset of enrollees in the Look AHEAD dual-energy x-ray absorptiometry substudy who completed the final visit, composed of men (DSE = 99; ILI = 94) and women (DSE = 134; ILI = 135) with type 2 diabetes and mean (SD) age 57.2 (6.4) years and BMI 34.9 (5.1) kg/m2 at randomization. Dual-energy x-ray absorptiometry measured total and regional fat and lean masses at randomization, at Years 1, 4, and 8, and at the final visit. Linear mixed-effects regressions were applied with adjustment for group, clinic, sex, age, race/ethnicity, and baseline body composition.

RESULTS

Weight and most body compartments were reduced by 2% to 8% (and BMI 4%) in ILI versus DSE in men but not women. ILI-induced loss of lean tissue did not show a lower percent lean mass versus DSE at 16 years after randomization.

CONCLUSION

ILI-related changes in weight, fat, and lean mass were detectable 12 to 16 years after randomization in men but, for unknown reasons, not in women. There was no evidence that the intervention led to a disproportionate loss of lean mass by the end of the study.

The 10-Year Effects of Intensive Lifestyle Intervention on Kidney Outcomes

Rationale & Objective

Limited data exist on longitudinal kidney outcomes after nonsurgical obesity treatments. We investigated the effects of intensive lifestyle intervention on kidney function over 10 years.

Study Design

Post hoc analysis of Action for Health in Diabetes (Look AHEAD) randomized controlled trial.

Setting & Participants

We studied 4,901 individuals with type 2 diabetes and body mass index of ≥25 kg/m2 enrolled in Look AHEAD (2001-2015). The original Look AHEAD trial excluded individuals with 4+ urine dipstick protein, serum creatinine level of >1.4 mg/dL (women), 1.5 mg/dL (men), or dialysis dependence.

Exposures

Intensive lifestyle intervention versus diabetes support and education (ie, usual care).

Outcome

Primary outcome was estimated glomerular filtration rate (eGFR, mL/min/1.73 m2) slope. Secondary outcomes were mean eGFR, slope, and mean urine albumin to creatinine ratio (UACR, mg/mg).

Analytical Approach

Linear mixed-effects models with random slopes and intercepts to evaluate the association between randomization arms and within-individual repeated measures of eGFR and UACR. We tested for effect modification by baseline eGFR.

Results

At baseline, mean eGFR was 89, and 83% had a normal UACR. Over 10 years, there was no difference in eGFR slope (+0.064 per year; 95% CI: -0.036 to 0.16; P = 0.21) between arms. Slope or mean UACR did not differ between arms. Baseline eGFR, categorized as eGFR of <80, 80-100, or >100, did not modify the intervention's effect on eGFR slope or mean.

Limitations

Loss of muscle may confound creatinine-based eGFR.

Conclusions

In patients with type 2 diabetes and preserved kidney function, intensive lifestyle intervention did not change eGFR slope over 10 years. Among participants with baseline eGFR <80, lifestyle intervention had a slightly higher longitudinal mean eGFR than usual care. Further studies evaluating the effects of intensive lifestyle intervention in people with kidney disease are needed.

Association between abdominal adiposity and cognitive decline in older adults: a 10-year community-based study

OBJECTIVES

This study aimed to investigate the association between abdominal adiposity and change in cognitive function in community-dwelling older adults.

DESIGN, SETTING, AND PARTICIPANTS

This longitudinal study included older adults aged ≥60 years without cognitive impairment who participated in the National Institute for Longevity Sciences - Longitudinal Study of Aging.

MEASUREMENTS

Cognitive function was evaluated biennially using the Mini-Mental State Examination (MMSE) over 10 years. Waist circumference (WC) was measured at the naval level, and subcutaneous fat area (SFA) and visceral fat area (VFA) were assessed using baseline computed tomography scans. WC, SFA, and VFA areas were stratified into sex-adjusted tertiles. A linear mixed model was applied separately for men and women.

RESULTS

This study included 873 older adults. In men, the groups with the highest levels of WC, SFA, and VFA exhibited a greater decline in MMSE score than the groups with the lowest levels (β [95% confidence interval]: WC, -0.12 [-0.23 to -0.01]; SFA, -0.13 [-0.24 to -0.02]; VFA, -0.11 [-0.22 to -0.01]). In women, the group with the highest level of WC and SFA showed a greater decline in MMSE score than the group with the lowest level (WC, -0.12 [-0.25 to -0.01]; SFA, -0.18 [-0.30 to -0.06]), but VFA was not associated with cognitive decline.

CONCLUSION

Higher WC, SFA, and VFA in men and higher WC and SFA in women were identified as risk factors for cognitive decline in later life, suggesting that abdominal adiposity involved in cognitive decline may differ according to sex.

Cardiovascular effects of weight loss in old adults with overweight/obesity according to change in skeletal muscle mass

BACKGROUND

Patients with overweight/obesity and type 2 diabetes are encouraged to lose weight, but not all losing weight gain better cardiovascular health, especially old adults. The change in skeletal muscle mass (SMM) could be the key that explains the heterogenous cardiovascular effects of weight loss. This study aims to assess whether the cardiovascular effects of weight loss vary for those gaining skeletal muscle along with weight loss.

METHODS

The old adults with overweight/obesity and type 2 diabetes in the Look AHEAD study having muscle measurement from dual-energy X-ray absorptiometry were included. Based on the weight change (WC) and SMM change (SMMC) between baseline and the 4-year follow-up, participants were allocated into three groups-weight gain (WG) group, weight loss with muscle loss (WL-ML) group and weight loss with muscle gain (WL-MG) group. Cox proportional hazards regression was performed to evaluate the cardiovascular risk of those gaining or losing SMM with weight loss compared with those gaining weight. Among the participants with weight loss, the ratio of SMMC/WC was calculated, and the association of SMMC/WC with primary cardiovascular outcome was assessed.

RESULTS

A total of 491 participants were included in the study with an average age of 64.56 ± 3.81 years old. A total of 47.0% were male and 49.9% were from the intensive lifestyle intervention arm. Based on their WC and SMMC, 43 were assigned to the WG group, 373 to the WL-ML group and 75 to the WL-MG group. Over a follow-up of almost 10 years, 97 participants encountered the primary endpoint. The WG group had the highest incidence of 25.59%, the WL-MG group had the lowest incidence of 9.33% and the WL-ML group had 21.18% (P = 0.040). In the fourth adjusted Cox model, the WL-MG group achieved significantly decreased odds of the primary endpoint compared with the WG group (hazard ratio [HR] 0.33, 95% confidence interval [CI] [0.12, 0.87], P = 0.026), whilst the WL-ML group did not (HR 0.91, 95% CI [0.47, 1.78], P = 0.670). Among the participants with weight loss, when SMMC/WC reached around 50%, this HR soared to approximately two-fold.

CONCLUSIONS

The participants gaining SMM along with weight loss achieved the lowest odds of adverse cardiovascular events, whilst those who lost SMM along with weight loss had comparable cardiovascular risk with those gaining weight. The more muscle lost during weight loss, the greater the harm. The cardiovascular effects of weight loss were modulated by whether the participants gained SMM meanwhile losing weight.

Body Fat Depletion: the Yin Paradigm for Treating Type 2 Diabetes

PURPOSE OF REVIEW

To highlight that body fat depletion (the Yin paradigm) with glucose-lowering treatments (the Yang paradigm) are associated with metabolic benefits for patients with type 2 diabetes mellitus (T2DM).

RECENT FINDINGS

The sodium-glucose cotransporter-2 inhibitor-mediated sodium/glucose deprivation can directly improve glycemic control and kidney outcome in patients with T2DM. The glucose deprivation might also promote systemic fatty acid β-oxidation to deplete ectopic/visceral fat and thereby contribute to the prevention of cardiovascular diseases. As with metabolic surgery, bioengineered incretin-based medications with potent anorexigenic and insulinotropic efficacy can significantly reduce blood glucose as well as body weight (especially in the ectopic/visceral fat depots). The latter effects could be a key contributor to their cardiovascular-renal protective effects. In addition to a healthy diet, the newer glucose-lowering medications, with body fat reduction effects, should be prioritized when treating patients with T2DM, especially for those with established cardiovascular/renal risks or diseases.

Clinical application of intermittent fasting for weight loss: progress and future directions

Intermittent fasting diets have become very popular in the past few years, as they can produce clinically significant weight loss. These diets can be defined, in the simplest of terms, as periods of fasting alternating with periods of eating. The most studied forms of intermittent fasting include: alternate day fasting (0-500 kcal per 'fast day' alternating with ad libitum intake on 'feast days'); the 5:2 diet (two fast days and five feast days per week) and time-restricted eating (only eating within a prescribed window of time each day). Despite the recent surge in the popularity of fasting, only a few studies have examined the health benefits of these diets in humans. The goal of this Review is to summarize these preliminary findings and give insights into the effects of intermittent fasting on body weight and risk factors for cardiometabolic diseases in humans. This Review also assesses the safety of these regimens, and offers some practical advice for how to incorporate intermittent fasting diets into everyday life. Recommendations for future research are also presented.

Sex-specific associations of fat mass and muscle mass with cardiovascular disease risk factors in adults with type 2 diabetes living with overweight and obesity: secondary analysis of the Look AHEAD trial

Background

Distinguishable sex differences exist in fat mass and muscle mass. High fat mass and low muscle mass are independently associated with cardiovascular disease (CVD) risk factors in people living with type 2 diabetes; however, it is unknown if the association between fat mass and CVD risk is modified by muscle mass, or vice versa. This study examined the sex-specific interplay between fat mass and muscle mass on CVD risk factors in adults with type 2 diabetes living with overweight and obesity.

Methods

Dual-energy X-ray absorptiometry (DXA) measures were used to compute fat mass index (FMI) and appendicular muscle mass index (ASMI), and participants were separated into high-fat mass vs. low-fat mass and high-muscle mass vs. low-muscle mass. A two-way analysis of covariance (ANCOVA: high-FMI vs. low-FMI by high-ASMI vs. low-ASMI) was performed on CVD risk factors (i.e., hemoglobin A1C [A1C]; high-density lipoprotein cholesterol; low-density lipoprotein cholesterol; triglycerides; systolic and diastolic blood pressure; cardiorespiratory fitness, depression and health related-quality of life [HR-QoL]) at baseline and following a 1-year intensive lifestyle intervention (ILI) for females and males separately, with a primary focus on the fat mass by muscle mass interaction effects.

Results

Data from 1,369 participants (62.7% females) who completed baseline DXA were analyzed. In females, there was a fat mass by muscle mass interaction effect on A1C (p = 0.016) at baseline. Post-hoc analysis showed that, in the low-FMI group, A1C was significantly higher in low-ASMI when compared to high-ASMI (60.3 ± 14.1 vs. 55.5 ± 13.5 mmol/mol, p = 0.023). In the high-FMI group, there was no difference between high-ASMI and low-ASMI (56.4 ± 12.5 vs. 56.5 ± 12.8 mmol/mol, p = 0.610). In males, only high-FMI was associated with higher A1C when compared to low-FMI (57.1 ± 14.4 vs. 54.2 ± 12.0 mmol/mol, p = 0.008) at baseline. Following ILI, there were significant fat mass by muscle mass interaction effects on changes in the mental component of HR-QoL in males.

Conclusion

Considering that A1C predicts future CVD, strategies to lower A1C may be especially important in females with low fat and low muscle mass living with type 2 diabetes. Our results highlight the complicated and sex-specific contribution of fat mass and muscle mass to CVD risk factors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01468-x.

Correlates of cardiorespiratory fitness among overweight or obese individuals with type 2 diabetes

INTRODUCTION

Mechanistic studies suggest that type 2 diabetes is independently associated with low cardiorespiratory fitness (CRF). Little is known about the CRF profile in type 2 diabetes; we assessed the correlates of low CRF among overweight/obese adults with type 2 diabetes.

RESEARCH DESIGN AND METHODS

A total of 4215 participants with type 2 diabetes and without cardiovascular disease underwent maximal exercise testing in the Look AHEAD (Action for Health in Diabetes) study. Low CRF was defined based on the Aerobics Center Longitudinal Study reference standards. Calorie intake and physical activity were assessed using questionnaires. Body fat composition was assessed using dual-energy X-ray absorptiometry.

RESULTS

Waist circumference, systolic blood pressure, glycemic measures, whole body fat, caloric intake, and fat-free mass were inversely associated with fitness across sex (all p<0.001). Comparing with moderate or high CRF groups, the low CRF group was associated with higher adjusted odds of obesity (OR 3.19 (95% CI 1.95 to 5.20) in men, 3.86 (95% CI 2.55 to 5.84)) in women), abdominal obesity (OR 3.99 (95% CI 2.00 to 7.96) in men, 2.28 (95% CI 1.08 to 4.79) in women), hypertension (OR 1.74 (95% CI 1.09 to 2.77) in men, 1.44 (95% CI 1.02 to 2.05) in women), metabolic syndrome (OR 5.52 (95% CI 2.51 to 12.14) in men, 2.25 (95% CI 1.35 to 3.76) in women), use of beta-blocker (1.22 (95% CI 0.86 to 1.73) in men, 1.33 (95% CI 1.03 to 1.73) in women), and ACE inhibitor/angiotensin-receptor blocker (1.86 (95% CI 1.39 to 2.50) in men, 1.07 (95% CI 0.86 to 1.32) in women). Women with low CRF had higher odds of current smoking (2.02 (95% CI 1.25 to 3.28)).

CONCLUSIONS

Low CRF was associated with increased odds of cardiometabolic correlates in a large cohort of adults with type 2 diabetes.

Machine learning approach to predicting albuminuria in persons with type 2 diabetes: An analysis of the LOOK AHEAD Cohort

Albuminuria and estimated glomerular filtration rate (e-GFR) are early markers of renal disease and cardiovascular outcomes in persons with diabetes. Although body composition has been shown to predict systolic blood pressure, its application in predicting albuminuria is unknown. In this study, we have used machine learning methods to assess the risk of albuminuria in persons with diabetes using body composition and other determinants of metabolic health. This study is a comparative analysis of the different methods to predict albuminuria in persons with diabetes mellitus who are older than 40 years of age, using the LOOK AHEAD study cohort-baseline characteristics. Age, different metrics of body composition, duration of diabetes, hemoglobin A1c, serum creatinine, serum triglycerides, serum cholesterol, serum HDL, serum LDL, maximum exercise capacity, systolic blood pressure, diastolic blood pressure, and the ankle-brachial index are used as predictors of albuminuria. We used Area under the curve (AUC) as a metric to compare the classification results of different algorithms, and we show that AUC for the different models are as follows: Random forest classifier-0.65, gradient boost classifier-0.61, logistic regression-0.66, support vector classifier -0.61, multilayer perceptron -0.67, and stacking classifier-0.62. We used the Random forest model to show that the duration of diabetes, A1C, serum triglycerides, SBP, Maximum exercise Capacity, serum creatinine, subtotal lean mass, DBP, and subtotal fat mass are important features for the classification of albuminuria. In summary, when applied to metabolic imaging (using DXA), machine learning techniques offer unique insights into the risk factors that determine the development of albuminuria in diabetes.

Drugs for Treating Obesity

Older medications approved for chronic weight management (orlistat, naltrexone/bupropion, liraglutide 3 mg and, in the USA, phentermine/topiramate) have not been widely adopted by health care providers. Those medications produce only modest additional weight loss when used to augment lifestyle intervention. However, semaglutide 2.4 mg weekly has recently emerged and produces much more weight loss - on average 15% weight loss at 1 year. Semaglutide's enhanced efficacy and that its class (GLP-1 receptor analogs) is well-known may result in more clinicians adopting pharmacotherapy. Furthermore, the first dedicated cardiovascular outcome trial powered for superiority testing an anti-obesity medication (SELECT) is underway with semaglutide 2.4 mg. A positive outcome will further promote the concept that weight management should be a primary target for cardiometabolic disease control. In phase 3, tirzepatide and cagrilintide/semaglutide combination are showing promise for even greater weight loss efficacy. Another recently approved medication takes a personalized medicine approach; setmelanotide is approved as a therapy for those with some of the ultra-rare genetic diseases characterized by severe, early onset obesity. This chapter reviews the currently available and anticipated medications for chronic weight management as well as those approved for the genetic and syndromic obesities.

Does Lifestyle Intervention Improve Health of Adults with Overweight/Obesity and Type 2 Diabetes? Findings from the Look AHEAD Randomized Trial

This paper reviews the main findings from the Action for Health in Diabetes (Look AHEAD) Trial, a randomized trial testing the long-term health effects of intensive lifestyle interventions (ILIs) in 5,145 persons with overweight/obesity and type 2 diabetes. Although the primary outcome originally focused on cardiovascular morbidity and mortality, secondary outcomes included a broad range of health parameters related to diabetes and obesity. As the cohort aged, study outcomes were expanded to include health problems affecting geriatric populations, such as cognitive impairment and disability.This review summarizes the history of this trial and presents findings related to a wide range of health outcomes. Studies are reviewed that showed positive impact of ILI on diabetes control and complications, depression, physical health-related quality of life, sleep apnea, incontinence, brain structure, and health care use and costs. Several composite indices were also positively impacted by ILI, including multimorbidity, geriatric syndromes, and disability-free life years. However, there are also some important outcomes that did not show significant differences between the intervention and control, including cardiovascular morbidity and mortality, cancer, cognitive function, and cognitive impairment; for several of these nonsignificant effects, post hoc analyses suggested that there may be differences among subgroups, raising the possibility that ILI may be beneficial to some but potentially harmful to others. The only adverse effects of ILI relative to diabetes support and education were on frailty fractures and the related negative effects on body composition and bone density. Through this review, the manuscript seeks to determine whether weight loss should be encouraged in this population; given the large number of beneficial effects, relative to the small number of adverse effects, the answer appears to be yes.

A randomized trial of exercise and diet on body composition in survivors of breast cancer with overweight or obesity

PURPOSE

Obesity increases the risk of cancer recurrence and death in survivors of breast cancer. This study tested the hypothesis that exercise alone, diet alone, and the combination of exercise plus diet reduce body weight and improve body composition in survivors of breast cancer.

METHODS

In this 2 × 2 factorial trial, 351 survivors of breast cancer with overweight or obesity were randomized to one of four treatment groups for 52 weeks: control, exercise alone, diet alone, or exercise plus diet. Endpoints included body weight and body composition measured by dual-energy x-ray absorptiometry.

RESULTS

After 52 weeks, compared with control, diet alone [- 5.39 kg (95% CI - 7.24, - 3.55);- 6.0% (95% CI - 8.0, - 3.9)] and exercise plus diet [- 6.68 kg (95% CI - 8.46, - 4.90);- 7.4% (95% CI - 9.4, - 5.4)] reduced body weight; exercise alone did not change body weight. Compared with control, diet alone [- 3.59 kg (95% CI - 5.00, - 2.17)] and exercise plus diet [- 4.28 kg (95% CI - 5.71, - 2.84)] reduced fat mass; exercise alone did not change fat mass. Compared with control, diet alone [- 0.82 kg (95% CI - 1.50, - 0.15)] and exercise plus diet [- 1.24 kg (95% CI - 1.92, - 0.56)] reduced lean mass; exercise alone did not change lean mass. Compared with control, exercise alone, diet alone, and exercise plus diet did not change bone mineral density.

CONCLUSION

In survivors of breast cancer with overweight or obesity, diet alone or diet plus exercise produced clinically meaningful weight loss at week 52. The majority of weight loss was fat mass.

Body fat predicts exercise capacity in persons with Type 2 Diabetes Mellitus: A machine learning approach

Diabetes mellitus is associated with increased cardiovascular disease (CVD) related morbidity, mortality and death. Exercise capacity in persons with type 2 diabetes has been shown to be predictive of cardiovascular events. In this study, we used the data from the prospective randomized LOOK AHEAD study and used machine learning algorithms to help predict exercise capacity (measured in Mets) from the baseline data that included cardiovascular history, medications, blood pressure, demographic information, anthropometric and Dual-energy X-Ray Absorptiometry (DXA) measured body composition metrics. We excluded variables with high collinearity and included DXA obtained Subtotal (total minus head) fat percentage and Subtotal lean mass (gms). Thereafter, we used different machine learning methods to predict maximum exercise capacity. The different machine learning models showed a strong predictive performance for both females and males. Our study shows that using baseline data from a large prospective cohort, we can predict maximum exercise capacity in persons with diabetes mellitus. We show that subtotal fat percentage is the most important feature for predicting the exercise capacity for males and females after accounting for other important variables. Until now, BMI and waist circumference were commonly used surrogates for adiposity and there was a relative under-appreciation of body composition metrics for understanding the pathophysiology of CVD. The recognition of body fat percentage as an important marker in determining CVD risk has prognostic implications with respect to cardiovascular morbidity and mortality.

Time-Restricted Eating to Improve Cardiovascular Health

PURPOSE OF REVIEW

Time-restricted eating (TRE) is a form of intermittent fasting that involves confining the eating window to 4-10 h and fasting for the remaining hours of the day. The purpose of this review is to summarize the current literature pertaining to the effects of TRE on body weight and cardiovascular disease risk factors.

RECENT FINDINGS

Human trial findings show that TRE reduces body weight by 1-4% after 1-16 weeks in individuals with obesity, relative to controls with no meal timing restrictions. This weight loss results from unintentional reductions in energy intake (~350-500 kcal/day) that occurs when participants confine their eating windows to 4-10 h/day. TRE is also effective in lowering fat mass, blood pressure, triglyceride levels, and markers of oxidative stress, versus controls. This fasting regimen is safe and produces few adverse events. These findings suggest that TRE is a safe diet therapy that produces mild reductions in body weight and also lowers several key indicators of cardiovascular disease in participants with obesity.

From famine to therapeutic weight loss: Hunger, psychological responses, and energy balance-related behaviors

Understanding physiological and behavioral responses to energy imbalances is important for the management of overweight/obesity and undernutrition. Changes in body composition and physiological functions associated with energy imbalances provide the structural and functional context in which to consider psychological and behavioral responses. Compensatory changes in physiology and behavior are more pronounced in response to negative than positive energy balances. The physiological and psychological impact of weight loss (WL) occur on a continuum determined by (i) the degree of energy deficit (ED), (ii) its duration, (iii) body composition at the onset of the energy deficit, and (iv) the psychosocial environment in which it occurs. Therapeutic WL and famine/semistarvation both involve prolonged EDs, which are sometimes similar in magnitude. The key differences are that (i) the body mass index (BMI) of most famine victims is lower at the onset of the ED, (ii) therapeutic WL is intentional and (iii) famines are typically longer in duration (partly due to the voluntary nature of therapeutic WL and disengagement with WL interventions). The changes in psychological outcomes, motivation to eat, and energy intake in therapeutic WL are often modest (bearing in mind the nature of the measures used) and can be difficult to detect but are quantitatively significant over time. As WL progresses, these changes become more marked. It appears that extensive WL beyond 10%-20% in lean individuals has profound effects on body composition and physiological function. At this level of WL, there is a marked erosion of psychological functioning, which appears to run in parallel to WL. Psychological resources dwindle and become increasingly focused on alleviating escalating hunger and food seeking behavior. Functional changes in fat-free mass, characterized by catabolism of skeletal muscle and organs may be involved in the drive to eat associated with semistarvation. Higher levels of body fat mass may act as a buffer to protect fat-free mass, functional integrity and limit compensatory changes in energy balance behaviors. The increase in appetite that accompanies therapeutic WL appears to be very different to the intense and all-consuming drive to eat that occurs during prolonged semistarvation. The mechanisms may also differ but are not well understood, and longitudinal comparisons of the relationship between body structure, function, and behavior in response to differing EDs in those with higher and lower BMIs are currently lacking.

Association of Baseline and Longitudinal Changes in Body Composition Measures With Risk of Heart Failure and Myocardial Infarction in Type 2 Diabetes: Findings From the Look AHEAD Trial

BACKGROUND

Intentional weight loss is associated with lower risk of heart failure (HF) and atherosclerotic cardiovascular disease among patients with type 2 diabetes. However, the contribution of baseline measures and longitudinal changes in fat mass (FM), lean mass (LM), and waist circumference (WC) to the risk of HF and myocardial infarction (MI) in type 2 diabetes is not well established.

METHODS

Adults from the Look AHEAD trial (Action for Health in Diabetes) without prevalent HF were included. FM and LM were predicted using validated equations and compared with dual-energy x-ray absorptiometry measurements in a subgroup. Adjusted Cox models were used to evaluate the associations of baseline and longitudinal changes in FM, LM, and WC over 1- and 4-year follow-up with risk of overall HF, HF with preserved ejection fraction (EF; EF ≥50%), HF with reduced EF (EF <50%), and MI.

RESULTS

Among 5103 participants, there were 257 incident HF events over 12.4 years of follow-up. Predicted and measured FM/LM were highly correlated (R²=0.87-0.90; n=1369). FM and LM decreased over 4-year follow-up with greater declines in the intensive lifestyle intervention arm. In adjusted analysis, baseline body composition measures were not significantly associated with HF risk. Decline in FM and WC, but not LM, over 1 year were each significantly associated with lower risk of overall HF (adjusted hazard ratio per 10% decrease in FM, 0.80 [95% CI, 0.68-0.95]; adjusted hazard ratio per 10% decrease in WC, 0.77 [95% CI, 0.62-0.95]). Decline in FM was significantly associated with lower risk of both HF subtypes. In contrast, decline in WC was significantly associated with lower risk of HF with preserved EF but not HF with reduced EF. Similar patterns of association were observed for 4-year changes in body composition and HF risk. Longitudinal changes in body composition were not significantly associated with risk of MI.

CONCLUSIONS

In adults with type 2 diabetes, a lifestyle intervention is associated with significant loss of FM and LM. Declines in FM and WC, but not LM, were each significantly associated with lower risk of HF but not MI. Furthermore, decline in WC was significantly associated with lower risk of HF with preserved EF but not HF with reduced EF. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT00017953.

Effect of a tailored home-based exercise program in patients with systemic sclerosis: A randomized controlled trial

OBJECTIVE

The aim was to evaluate the effect of a home-based exercise program on functional capacity, health-related quality of life (HRQoL), and disability, in patients with systemic sclerosis (SSc).

METHODS

A 6-month randomized controlled trial was conducted on SSc patients by comparing a home-based minimally supervised exercise program (exercise on a stationary cycle and strengthening of upper limbs; stretching of the hands) with usual care. At baseline and after 3 and 6 months, the patients underwent: 6 minutes walking test; hand mobility in scleroderma test; maximal exercise test on an ergocycle; strength measures (handgrip, quadriceps, and biceps). HRQoL (short-form 36 [SF-36]) and disability (health assessment questionnaire disability index [HAQ-DI]) were measured at the same time.

RESULTS

Forty-four patients participated in the study. Twenty-two were randomly assigned to the intervention group (IG, mean age 63.60 ± 10.40 years) and 22 to the control group (CG, 61.80 ± 14.40 years). At 6 months, the distance walked in 6 minutes increased by 46 m (baseline 486, 95% CI 458-513 m; 6 months 532, 95% CI 504-561 m) in IG, whereas it decreased by 5 m (baseline 464, 95% CI 431-497 m; 6 months 459, 95% CI 427-490 m) in CG with a significantly different temporal trend at the between-groups comparison (P < .001). An improvement was also observed for strength measures (handgrip, P = .003; quadriceps, P < .001; biceps, P < .001), for the SF-36 physical component score (P < .001) and for the HAQ-DI (P = .011).

CONCLUSIONS

This study indicates that in SSc patients, a minimally supervised home-based exercise program improves physical performance, quality of life, and disability in comparison with usual care.

Team-based "Get-a-Grip" lifestyle management programme in the treatment of obesity

•

Team-based one-year lifestyle programme led to mean weight loss of 4.8 kg.

•

Among the participants 44% lost ≥ 5%, while 21% lost ≥ 10% of their initial weight.

•

Beneficial changes were detected in muscle mass, body fat, and visceral fat.

•

Systolic and diastolic blood pressure was reduced significantly.

This study examined weight loss during an extensive 1-year lifestyle programme in primary care in Finland in overweight subjects (n = 134, age 18–69 years; BMI > 30, or BMI > 25 with a comorbidity that would benefit from weight loss) between 2009 and 2013 in a single arm design. The programme included four medical doctor visits, five sessions by a dietitian (advice on diet and on-location shopping behaviour), cooking classes, exercise supervised by personal trainer, and group discussions. A motivational interview method was applied.

Of the 134 participants, 92 (69%) completed the 1-year programme. Among the participants 44% lost ≥ 5%, while 21% lost ≥ 10% of their initial body weight. In intention-to-treat-analyses, the mean weight loss during one year was 4.8 kg (p < 0.001). Mean BMI decreased by 1.7 kg/m² (p < 0.001) and waist circumference by 5.6 cm (p < 0.001). Mean muscle mass increased by 3.3% (p < 0.001), and body fat decreased by 5.0% (p < 0.001). After the programme mean visceral fat content was reduced by 6.4%, systolic blood pressure by 8 mmHg (p < 0.001), and diastolic blood pressure by 6 mmHg (p < 0.001).

In conclusion, retention to the team-based lifestyle management programme resulted in moderate but significant weight loss with beneficial changes in body composition, and the trend to lose weight was maintained throughout the year.

Trial registration: Clinicaltrials.gov identifier NCT04003259.

Physical activity impacts insulin sensitivity post metabolic bariatric surgery in adolescents with severe obesity

BACKGROUND/OBJECTIVES

We hypothesized that physical activity (PA) improves insulin sensitivity in adolescents with severe obesity beyond that attributable to metabolic bariatric surgery (MBS).

SUBJECTS/METHODS

StepWatch^TM monitors objectively measured PA in 88 participants in the Teen Longitudinal Assessment of Bariatric Surgery (Teen-LABS) study. Primary outcomes included absolute change in fasting insulin, HOMA-IR, and fasting glucose from pre-surgery (baseline) to 6, 12, 24, and 36 months post-MBS. SAS PROC TRAJ generated activity trajectories based on probability and individual participant step count trajectories. Linear regression models were used, adjusted for baseline value, visit, surgical procedure, sex, and percent change in BMI. Additional models adjusted for percent change in iliac waist circumference (IWC) or percent body fat (BF), measured by bio-impedance.

RESULTS

Two activity trajectories were identified: more active (MA, n = 13) and less active (LA, n = 75). MA baseline mean daily step count was >6000, increasing to >9000 at 2 years. LA mean daily step count remained at ~4000. Few participants recorded moderate step activity (cadence >80 steps/minute). Still, fasting insulin and HOMA-IR differed in association with activity trajectoy. MA was associated with a greater absolute decrease in fasting insulin (-7.8 μU/ml [95% CI: (-11.8, -3.7)], p ≤ 0.001) and a greater decrease in HOMA-IR (-1.9 [95% CI: (-3.0, -0.7)], p = 0.001), when adjusted for percent change in BMI. The significant independent effect of MA remained when adjusted for percent change in IWC or percent BF. Clinically, 100% of MA trajectory participants normalized fasting insulin, HOMA-IR, and fasting glucose by 6 months and normalization remained throughout the 36 months follow up. In contrast, 76.3 and 65.8% of LA trajectory participants normalized fasting insulin and HOMA-IR, respectively, by 12 months with 28.6% of both remaining normalized at 36 months.

CONCLUSIONS

PA is independently associated with improved insulin sensitivity beyond that attributable to MBS in adolescents with severe obesity.

Metabolically healthy obesity: what's in a name?

Metabolically healthy obesity refers to an obesity phenotype with no or little evidence of metabolic dysfunction. Lower liver fat content and visceral adipose tissue, greater insulin sensitivity and secretion, greater cardiorespiratory fitness, and a predominantly lower body (i.e., leg) fat deposition are key physiological traits of a metabolically healthy phenotype. About 35% of all subjects with obesity are metabolically healthy. These individuals have approximately half the risk of developing type 2 diabetes and cardiovascular disease compared with metabolically unhealthy subjects with obesity, but they still have a significantly greater risk (by 50-300%) compared with metabolically healthy lean subjects. Therefore, absence of metabolic risk factors in people with obesity should not be a contraindication for weight-loss treatment. Metabolically healthy obesity needs to be treated, and this need is reinforced by the fact that this phenotype is not stable over time, as ∼50% of these subjects will cease being metabolically healthy within ∼10 y. Intervening early is therefore important. Weight loss dose-dependently decreases visceral adipose tissue and liver fat content, and it improves multiorgan insulin sensitivity and β-cell function (i.e., it beneficially affects many of the physiological traits of a metabolically healthy phenotype); however, weight loss is very difficult to maintain. This typically results in disappointment among patients and hinders adherence, which is likely critical for the limited success of most weight-loss treatments in the long term. On the other hand, using ≥1 metabolic health targets in a non-weight-loss-centered treatment paradigm that includes prudent dietary changes and increased physical activity can serve as an appropriate first goal that can help motivate patients toward the long-term goals of obesity treatment.

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.

Novel Smartphone Game Improves Physical Activity Behavior in Type 2 Diabetes

INTRODUCTION

Many type 2 diabetes patients show insufficient levels of physical activity and are often unmotivated to change physical activity behaviors. This study investigated whether a newly developed smartphone game delivering individualized exercise and physical activity promotion through an elaborate storyline can generate sustained improvements in daily physical activity (steps/day).

STUDY DESIGN

Thirty-six participants were enrolled in this 24-week RCT between August 2016 and April 2018. After baseline assessment, participants were randomized in equal numbers to the intervention or control condition. Data analysis was performed in May-June 2018.

SETTING/PARTICIPANTS

Inactive, overweight type 2 diabetes patients, aged 45-70 years, were recruited through advertising and from hospitals and diabetes care centers in the Basel, Switzerland, metropolitan area.

INTERVENTION

Participants were instructed to play the innovative smartphone game (intervention group) or to implement the recommendations from the baseline lifestyle counseling (control group) autonomously during the 24-week intervention period.

MAIN OUTCOME MEASURES

Primary outcomes were changes in daily physical activity (steps/day); changes in aerobic capacity, measured as oxygen uptake at the first ventilatory threshold; and changes in glycemic control, measured as HbA1c.

RESULTS

Daily physical activity increased by an average of 3,998 (SD=1,293) steps/day in the intervention group and by an average of 939 (SD=1,156) steps/day in the control group. The adjusted difference between the two groups was 3,128 steps/day (95% CI=2,313, 3,943, p<0.001). The increase in daily physical activity was accompanied by an improved aerobic capacity (adjusted difference of oxygen uptake at the first ventilatory threshold of 1.9 mL/(kg·min), 95% CI=0.9, 2.9, p<0.001). Glycemic control (HbA1c) did not change over the course of the intervention.

CONCLUSIONS

A novel, self-developed smartphone game, delivering multidimensional home-based exercise and physical activity promotion, significantly increases daily physical activity (steps/day) and aerobic capacity in inactive type 2 diabetes patients after 24 weeks. The ability of the game to elicit a sustained physical activity motivation may be relevant for other inactive target groups with chronic diseases.

TRIAL REGISTRATION

This study is registered at www.clinicaltrials.gov NCT02657018.

Weight Cycling as a Risk Factor for Low Muscle Mass and Strength in a Population of Males and Females with Obesity

OBJECTIVE

This study aimed to determine whether multiple weight cycles in adulthood are an independent predictor of lower muscle mass and reduced strength, with potential implication for sarcopenia in adults with obesity.

METHODS

A total of 60 males and 147 females with obesity were included, with a mean BMI of 37.9 ± 6.0 kg/m² and a mean age of 52.6 ± 12.4 years. Muscle strength was evaluated with handgrip and appendicular skeletal muscle mass was measured with dual-energy x-ray absorptiometry.

RESULTS

Participants were categorized into the following three groups: non-weight cyclers, mild weight cyclers, and severe weight cyclers. From a binary logistic regression that considered muscle mass categories as a dependent variable and weight cycling categories, age, and sex as independent variables, severe weight cyclers showed a 3.8-times increased risk of low muscle mass (95% CI: 1.42-10.01). Considering handgrip strength categories as a dependent variable and weight cycling categories, age, sex, and BMI as independent variables, severe weight cycling was associated with an increased risk of low muscle mass (about 6.3 times, 95% CI: 1.96-20.59). Severe weight cyclers showed a 5.2-times greater risk of developing sarcopenia.

CONCLUSIONS

In adults with obesity, weight cycling is associated with lower muscle mass and strength and a greater likelihood of developing sarcopenic obesity.

Body composition changes in diabetes and aging

Aging is associated with changes in body composition, including both fat gain and muscle loss beginning in middle age, and is associated with increased risk of type 2 diabetes. Moreover, changes in fat distribution take place in adults as they age and may contribute to the increased risk of type 2 diabetes. Recent literature has shown differences in the age-related changes in body composition by diabetes status suggesting that some of these changes might not only be a risk factor of the development of diabetes but could also be a consequence of the disease. In this article, we review the current evidence on body composition changes that take place in adults after the diagnosis of type 2 diabetes and compare them to those observed in adults without diabetes as they age. We also review the effect of various lifestyle, pharmacological, and surgical treatments that lower blood glucose on body composition in adults with type 2 diabetes.

Comparative Effects of Medical Versus Surgical Weight Loss on Body Composition: a Pilot Randomized Trial

OBJECTIVE

Bariatric surgery leads to more rapid and greater weight loss (WL) compared to medical weight loss (MWL), but the differences in body composition (BC) changes for these modalities remain unclear. Due to the known health risks associated with central adiposity, we compared the changes in regional distribution of fat mass (FM) and lean mass (LM) after surgical versus MWL.

METHODS

In this 1:1:1 randomized trial among 15 persons with type 2 diabetes and body mass index (BMI) 30-39.9 kg/m², we compared changes in BC, by dual-energy X-ray absorptiometry and abdominal computerized tomography, at time of 10%WL or 9 months after intervention (whichever came first). Participants underwent MWL, adjustable gastric banding (AGB), or Roux-en-Y gastric bypass (RYGB). Non-parametric tests evaluated BC differences (FM, LM, and visceral adipose tissue [VAT]) within and across all three arms and between pair-wise comparisons.

RESULTS

Twelve female participants (75% African American) completed the study. Patient age, BMI, and baseline anthropometric characteristics were similar across study arms. AGB lost more LM (MWL - 5.2%, AGB - 10.3%, p = 0.021) and VAT (MWL + 10.9%, AGB - 28.0%, p = 0.049) than MWL. RYGB tended to lose more VAT (MWL +10.9%, RYGB - 20.2%, p = 0.077) than MWL. AGB tended to lose more LM than RYGB (AGB - 12.38%, RYGB - 7.29%, p = 0.15).

CONCLUSIONS

At similar WL, AGB lost more LM and VAT than MWL; RYGB similarly lost more VAT. Given the metabolic benefits of reducing VAT and retaining LM, larger studies should confirm the changes in BC after surgical versus medical WL.

CLINICAL TRIAL REGISTRATION

NCTDK089557 - ClinicalTrials.gov.

Long-Term Effects of Randomization to a Weight Loss Intervention in Older Adults: A Pilot Study

Randomized, controlled trials (RCTs) show intentional weight loss improves body composition and physical function in older adults; however, the long-term benefits (and risks) are unknown. We conducted a pilot study to assess the feasibility of recalling prior RCT participants to examine the long-term effects of intentional weight loss on body composition and physical function. A weighted, random sample of 60 older adults who were randomized to caloric restriction plus exercise (CR + EX) or exercise (EX) only in 5 prior RCTs (mean age at randomization, 67.3 years; 69% women, 80% white) were invited to participate. Follow-up was obtained on 89% (42 clinic visits, 10 phone interviews, 1 death) an average of 3.5 years (range, 2.2-5.8 years) after RCT completion. Despite greater weight, fat and lean mass loss during the RCT (mean difference in change (95% CI): -4.19 (-7.52, -0.86), -2.75 (-5.10, -0.40), and -2.32 (-3.69, -0.95) kg, respectively) in those randomized to CR + EX, long-term changes in weight (2.05 (-2.35, 6.45) kg) and body composition (1.80 (-1.56, 5.17) and 0.03 (-2.20, 2.26) kg for fat and lean mass, respectively) from baseline and physical function at long-term follow-up (mean difference in 400-m walk and SPPB (95% CI): 23.2 (-19.3, 65.6) sec and -0.03 (-1.02, 0.96) points, respectively) were similar in CR + EX and EX only. Although improvements in weight and body composition following intentional weight loss may not be sustained long-term, physical function does not appear to be negatively impacted. A larger study is needed to confirm these results.

Body Fat Loss Automatically Reduces Lean Mass by Changing the Fat-Free Component of Adipose Tissue

Fat-free mass or lean tissue mass includes nonskeletal muscle components such as the fat-free component of adipose tissue fat cells. This fat-free component of adipose tissue may need to be taken into consideration when large changes in body fat occur following a weight loss intervention. It is not uncommon to see a loss of lean mass with interventions designed to promote the loss of large amounts of fat mass. However, after eliminating the influence of the fat-free component of adipose tissue on dual-energy x-ray absorptiometry (DXA)-derived lean mass, the original loss of lean mass is no longer observed or is markedly reduced. This suggests that the majority of the lean mass lost with dieting may be the fat-free component of adipose tissue. To accurately estimate the change in lean tissue, eliminating the fat-free adipose tissue from DXA-derived lean mass is needed when large changes in body fat occur following an intervention.

Development and relative validation of a short food frequency questionnaire for assessing dietary intakes of non-alcoholic fatty liver disease patients

Purpose

This work aimed to design and validate a novel short food frequency questionnaire (SFFQ) to assess habitual intakes of food items related to non-alcoholic fatty liver disease (NAFLD) in a cohort of European patients.

Methods

A 48-item SFFQ was created, with questions from existing FFQs and expert knowledge, emphasizing foods and nutrients implicated in NAFLD pathogenesis. Consenting, fibroscan-diagnosed, NAFLD patients completed the SFFQ during a short interview and were asked to complete a 4-day diet diary (4DDD) at home for return by mail. Nutritional intakes were assessed utilizing the myfood24™ food composition dataset and estimated energy requirements (EER) were calculated using sex-, age- and weight-specific equations. Agreement between the dietary instruments was assessed by Spearman correlations and Bland Altman analysis.

Results

Fifty-five patients completed both the SFFQ and the 4DDD within 30 weeks; 42 (76%) were diagnosed with simple steatosis, whereas 13 (24%) had biopsy-proven steatohepatitis; the majority were overweight or obese, with a median (25th; 75th percentile) BMI of 33.2 kg/m² (29.3; 36.0). Reported energy intakes were well below EER with a median intake of 73% of requirements, suggesting widespread under-reporting. Significant correlations were observed between sugar (r = 0.408, P = 0.002), fat (r = 0.44, P = 0.001), fruits (r = 0.51, P = 0.0001) and vegetables (r = 0.40, P = 0.0024) measurements by the SFFQ and 4DDD. Bland Altman plots with regression analysis demonstrated broad comparability with the 4DDD for intakes of fat (bias − 13.8 g/day) and sugar (bias  + 12.9 g/day).

Conclusions

A novel SFFQ designed to be minimally burdensome to participants was effective at assessing dietary intakes in NAFLD patients.

Electronic supplementary material

The online version of this article (10.1007/s00394-019-01926-5) contains supplementary material, which is available to authorized users.

Cross-Sectional and Longitudinal Association between Glycemic Status and Body Composition in Men: A Population-Based Study

This study sought to evaluate the associations between changes in glycemic status and changes in total body (TB), trunk, and appendicular fat (FM) and lean mass (LM) in men. A population-based study of men aged 20⁻66 years at baseline were included in cross-sectional (n = 430) and three-year longitudinal (n = 411) analyses. Prediabetes was defined as fasting glucose 100⁻125 mg/dL. Type 2 diabetes (T2D) was determined by: self-reported diabetes, current anti-diabetic drug use (insulin/oral hypoglycemic agents), fasting glucose (≥126 mg/dL), or non-fasting glucose (≥200 mg/dL). Body composition was evaluated by dual-energy X-ray absorptiometry. Longitudinal analyses showed that changes in TB FM and LM, and appendicular LM differed among glycemic groups. Normoglycemic men who converted to prediabetes lost more TB and appendicular LM than men who remained normoglycemic (all, p < 0.05). Normoglycemic or prediabetic men who developed T2D had a greater loss of TB and appendicular LM than men who remained normoglycemic (both, p < 0.05). T2D men had greater gains in TB FM and greater losses in TB and appendicular LM than men who remained normoglycemic (all, p < 0.05). Dysglycemia is associated with adverse changes in TB and appendicular LM.

Ad Libitum Mediterranean and Low-Fat Diets Both Significantly Reduce Hepatic Steatosis: A Randomized Controlled Trial

Although diet-induced weight loss is first-line treatment for patients with nonalcoholic fatty liver disease (NAFLD), long-term maintenance is difficult. The optimal diet for improvement in either NAFLD or associated cardiometabolic risk factors, regardless of weight loss, is unknown. We examined the effect of two ad libitum isocaloric diets (Mediterranean [MD] or low fat [LF]) on hepatic steatosis (HS) and cardiometabolic risk factors. Subjects with NAFLD were randomized to a 12-week blinded dietary intervention (MD vs. LF). HS was determined by magnetic resonance spectroscopy (MRS). From a total of 56 subjects enrolled, 49 completed the intervention and 48 were included for analysis. During the intervention, subjects on the MD had significantly higher total and monounsaturated fat, but lower carbohydrate and sodium, intakes compared to LF subjects (P < 0.01). At week 12, HS had reduced significantly in both groups (P < 0.01), and there was no difference in liver fat reduction between groups (P = 0.32), with mean (SD) relative reductions of 25.0% (±25.3%) in LF and 32.4% (±25.5%) in MD. Liver enzymes also improved significantly in both groups. Weight loss was minimal and not different between groups (-1.6 [±2.1] kg in LF vs -2.1 [±2.5] kg in MD; P = 0.52). Within-group improvements in Framingham Risk Score (FRS), total cholesterol, serum triglyceride (TG), and glycated hemoglobin (HbA1c) were observed in the MD (all P < 0.05), but not with the LF diet. Adherence was higher for the MD compared to LF (88% vs. 64%; P = 0.048). Conclusion: Ad libitum low-fat and Mediterranean diets both improve HS to a similar degree.

Physical Function Following a Long-Term Lifestyle Intervention Among Middle Aged and Older Adults With Type 2 Diabetes: The Look AHEAD Study

Background

Lifestyle interventions have been shown to improve physical function over the short term; however, whether these benefits are sustainable is unknown. The long-term effects of an intensive lifestyle intervention (ILI) on physical function were assessed using a randomized post-test design in the Look AHEAD trial.

Methods

Overweight and obese (body mass index ≥ 25 kg/m2) middle-aged and older adults (aged 45-76 years at enrollment) with type 2 diabetes enrolled in Look AHEAD, a trial evaluating an ILI designed to achieve weight loss through caloric restriction and increased physical activity compared to diabetes support and education (DSE), underwent standardized assessments of performance-based physical function including a 4- and 400-m walk, lower extremity physical performance (expanded Short Physical Performance Battery, SPPBexp), and grip strength approximately 11 years postrandomization and 1.5 years after the intervention was stopped (n = 3,783).

Results

Individuals randomized to ILI had lower odds of slow gait speed (<0.8 m/s) compared to those randomized to DSE (adjusted OR [95% CI]: 0.84 [0.71 to 0.99]). Individuals randomized to ILI also had faster gait speed over 4- and 400-m (adjusted mean difference [95% CI]: 0.019 [0.007 to 0.031] m/s, p = .002, and 0.023 [0.012 to 0.034] m/sec, p < .0001, respectively) and higher SPPBexp scores (0.037 [0.011 to 0.063], p = .005) compared to those randomized to DSE. The intervention effect was slightly larger for SPPBexp scores among older versus younger participants (0.081 [0.038 to 0.124] vs 0.013 [-0.021 to 0.047], p = .01).

Conclusions

An intensive lifestyle intervention has modest but significant long-term benefits on physical function in overweight and obese middle-aged and older adults with type 2 diabetes.

ClinicalTrials.gov Identifier

NCT00017953.

Metabolic Flexibility as an Adaptation to Energy Resources and Requirements in Health and Disease

The ability to efficiently adapt metabolism by substrate sensing, trafficking, storage, and utilization, dependent on availability and requirement, is known as metabolic flexibility. In this review, we discuss the breadth and depth of metabolic flexibility and its impact on health and disease. Metabolic flexibility is essential to maintain energy homeostasis in times of either caloric excess or caloric restriction, and in times of either low or high energy demand, such as during exercise. The liver, adipose tissue, and muscle govern systemic metabolic flexibility and manage nutrient sensing, uptake, transport, storage, and expenditure by communication via endocrine cues. At a molecular level, metabolic flexibility relies on the configuration of metabolic pathways, which are regulated by key metabolic enzymes and transcription factors, many of which interact closely with the mitochondria. Disrupted metabolic flexibility, or metabolic inflexibility, however, is associated with many pathological conditions including metabolic syndrome, type 2 diabetes mellitus, and cancer. Multiple factors such as dietary composition and feeding frequency, exercise training, and use of pharmacological compounds, influence metabolic flexibility and will be discussed here. Last, we outline important advances in metabolic flexibility research and discuss medical horizons and translational aspects.

Impact of Intensive Lifestyle Intervention on Disability-Free Life Expectancy: The Look AHEAD Study

OBJECTIVE

The impact of weight loss intervention on disability-free life expectancy in adults with diabetes is unknown. We examined the impact of a long-term weight loss intervention on years spent with and without physical disability.

RESEARCH DESIGN AND METHODS

Overweight or obese adults with type 2 diabetes age 45-76 years (n = 5,145) were randomly assigned to a 10-year intensive lifestyle intervention (ILI) or diabetes support and education (DSE). Physical function was assessed annually for 12 years using the 36-Item Short Form Health Survey. Annual incidence of physical disability, mortality, and disability remission were incorporated into a Markov model to quantify years of life spent active and physically disabled.

RESULTS

Physical disability incidence was lower in the ILI group (6.0% per year) than in the DSE group (6.8% per year) (incidence rate ratio 0.88 [95% CI 0.81-0.96]), whereas rates of disability remission and mortality did not differ between groups. ILI participants had a significant delay in moderate or severe disability onset and an increase in number of nondisabled years (P < 0.05) compared with DSE participants. For a 60-year-old, this effect translates to 0.9 more disability-free years (12.0 years [95% CI 11.5-12.4] vs. 11.1 years [95% CI 10.6-11.7]) but no difference in total years of life. In stratified analyses, ILI increased disability-free years of life in women and participants without cardiovascular disease (CVD) but not in men or participants with CVD.

CONCLUSIONS

Long-term lifestyle interventions among overweight or obese adults with type 2 diabetes may reduce long-term disability, leading to an effect on disability-free life expectancy but not on total life expectancy.

Poor Physical Function as a Marker of Sarcopenia in Adults with Class II/III Obesity

BACKGROUND

Adults with class II/III obesity [body mass index (in kg/m2) ≥35] may present with a phenotype characterized by low lean mass and excess fat mass, a condition known as sarcopenic obesity (SO). Little is known about the prevalence and relevance of SO in these individuals, primarily due to a lack of relevant diagnostic criteria.

OBJECTIVE

Here, we explored the definition of SO based on physical function as an outcome of interest in adults with class II/III obesity and applied this definition to compare clinical characteristics between SO and non-SO patients.

METHODS

In this cross-sectional analysis, patients' demographic, anthropometric, and biochemical characteristics, as well as comorbidities and physical activity levels, were collected at an obesity specialty clinic prior to any treatment. Body composition was assessed by dual-energy X-ray absorptiometry. Physical function was assessed by self-reported difficulties with activities of daily living (ADLs) from an 11-item questionnaire. Five SO definitions were tested against reported difficulty with ADLs with the use of receiver operating characteristic (ROC) analysis.

RESULTS

A total of 120 subjects (86% women) aged 46 ± 11 y were included. Based on ROC analysis, SO was best defined by an appendicular skeletal mass (ASM)/weight x 100 (%) <19.35% for women and <24.33% for men, resulting in a prevalence of 25% (n = 30, women 22.3%, men 41.2%). SO was significantly associated with older age, higher waist circumference, higher triglycerides, greater use of antihypertensive medications, and lower physical activity.

CONCLUSIONS

In this sample of adults with class II/III obesity, difficulties with ADLs were best associated with measures of ASM in relation to total body weight. Patients identified with SO using this criterion presented with poorer clinical outcomes such as factors of elevated cardiometabolic risk.

Lifestyle interventions for improving health and health behaviours in women with type 2 diabetes: A systematic review of the literature 2011-2017

The development and maintenance of healthy lifestyle behaviours are among the most promising strategies for reducing complications and premature death among women living with type 2 diabetes mellitus (T2DM). However, despite the potential benefits of these interventions, they have had varying success and the sustained uptake of the recommended lifestyle modifications is limited. This paper reviews research on the impact of lifestyle interventions aimed at improving health and health behaviours in women with T2DM. In a systematic review of the literature, empirical literature from 2011 to 2017 is examined to explore the effects of various lifestyle interventions on a number of objective and subjective health indicators in women with T2DM. A total of 18 intervention studies in women aged between 21 and 75 years were included in this narrative review. Interventions included education/counselling, exercise, diet, or combined components of varying duration. The included studies used a variety of objective indicators, including glycaemic control, lipid profile and anthropometric indices, as well as a number of diabetes-specific and generic subjective scales (for example, the Diabetes Problem Solving Inventory and the Short Form 36). Significant heterogeneity was noted in the interventions and also the study findings, although exercise interventions tended to yield the most consistent benefit in relation to glycaemic control, while exercise/dietary interventions generally improved anthropometric indices. The findings from this review did not consistently suggest the greater value of any one type of intervention. Future research should consider interventions that target multiple health behaviours and emphasize health literacy, self-efficacy, and problem-solving skills.

The Effect of Intentional Weight Loss on Fracture Risk in Persons With Diabetes: Results From the Look AHEAD Randomized Clinical Trial

Intentional weight loss is an important treatment option for overweight persons with type 2 diabetes mellitus (DM), but the effects on long-term fracture risk are not known. The purpose of this Look AHEAD analysis was to evaluate whether long-term intentional weight loss would increase fracture risk in overweight or obese persons with DM. Look AHEAD is a multicenter, randomized clinical trial. Recruitment began in August 2001 and follow-up continued for a median of 11.3 years at 16 academic centers. A total of 5145 persons aged 45 to 76 years with DM were randomized to either an intensive lifestyle intervention (ILI) with reduced calorie consumption and increased physical activity designed to achieve and maintain ≥7% weight loss or to diabetes support and education intervention (DSE). Incident fractures were ascertained every 6 months by self-report and confirmed with central adjudication of medical records. The baseline mean age of participants was 59 years, 60% were women, 63% were white, and the mean BMI was 36 kg/m2 . Weight loss over the intervention period (median 9.6 years) was 6.0% in ILI and 3.5% in DSE. A total of 731 participants had a confirmed incident fracture (358 in DSE versus 373 in ILI). There were no statistically significant differences in incident total or hip fracture rates between the ILI and DSE groups. However, compared to the DSE group, the ILI group had a statistically significant 39% increased risk of a frailty fracture (HR 1.39; 95% CI, 1.02 to 1.89). An intensive lifestyle intervention resulting in long-term weight loss in overweight/obese adults with DM was not associated with an overall increased risk of incident fracture but may be associated with an increased risk of frailty fracture. When intentional weight loss is planned, consideration of bone preservation and fracture prevention is warranted. © 2017 American Society for Bone and Mineral Research.

Loss of skeletal muscle mass and its predictors in type 2 diabetes patients under a multifaceted treatment approach

Background

Weight loss, which is an effective method for reducing visceral fat, may cause a concomitant loss of skeletal muscle mass. The aim of this study was to elucidate the changes in visceral fat and skeletal muscle mass in response to diabetes treatment including weight control.

Methods

For 6 months we observed the changes in the body compositions of 72 Japanese patients with type 2 diabetes who underwent multifaceted treatment including educational hospitalization. Visceral fat area (VFA) and appendicular skeletal muscle mass (ASM) were measured using a bioelectrical impedance method and dual-energy X-ray absorptiometry, respectively.

Results

During the follow-up period, VFA reduced significantly whereas the average ASM did not change. Changes in ASM were strongly positively associated with changes in body weight (r = 0.50). Additionally, in an analysis of covariance, an above-median BMI (27 kg/m²) and above-median VFA (110 cm²) at baseline were found to be independent predictors of ASM reduction prevention. Of the 55 patients who lost weight, those who had a baseline VFA of ≥110 cm² had significantly greater reductions in VFA than those with a baseline VFA of <110 cm² (p < 0.01). ASM reduced significantly in patients with a VFA of <110 cm² (p < 0.01), but not in those with a VFA of ≥110 cm² (p = 0.98).

Conclusions

Baseline accumulation of visceral fat may predict a preferential reduction of visceral fat rather than skeletal muscle during weight control programs in type 2 diabetes patients.

Prevalence of Sarcopenic Obesity in Adults with Class II/III Obesity Using Different Diagnostic Criteria

Background/Objective. Sarcopenic obesity (SO) is a hidden condition of reduced lean soft tissue (LST) in context of excess adiposity. SO is most commonly reported in older adults and both its risk and prevalence increase with age. A variety of body composition indices and cut points have been used to define this condition, leading to conflicting prevalence and risk prediction. Here, we investigate variability in the prevalence of SO in an adult sample of individuals with class II/III obesity (BMI ≥ 35 kg/m2) using different diagnostic criteria. Methods. SO definitions were identified from a literature review of studies using dual-energy X-ray absorptiometry (DXA) to assess LST. Demographics, anthropometrics, and body composition (by DXA) were measured in n = 120, 86% female (46.9 ± 11.1 years). Results. LST was extremely variable in individuals, even with similar body sizes, and observed across the age spectrum. The prevalence of SO ranged from 0 to 84.5% in females and 0 to 100% in males, depending upon the definition applied, with higher prevalence among definitions accounting for measures of body size or fat mass. Conclusion. SO is present, yet variable, in adults with class II/III obesity. Accounting for body mass or fat mass may identify a higher number of individuals with SO, although risk prediction remains to be studied.

Changes in skeletal muscle and organ size after a weight-loss intervention in overweight and obese type 2 diabetic patients

BACKGROUND

The effect of a weight-loss intervention on the masses of lean tissues and organs in humans is not well known.

OBJECTIVE

We studied the effects of a diet and exercise weight-loss intervention on skeletal muscle (SM) mass and selected organs over 2 y using MRI in overweight adults with type 2 diabetes.

DESIGN

Participants were 53 women and 39 men [mean ± SD: age 58 ± 7 y; body mass index (BMI; in kg/m²) 32 ± 3] enrolled in the Look AHEAD (Action for Health in Diabetes) trial and randomly assigned to an intensive lifestyle intervention (ILI) or diabetes support and education (DSE) on whom 2 y of data were collected. MRI-derived measurements of SM, heart, liver, kidney, spleen, and pancreas were acquired.

RESULTS

Adjusted for baseline weight, height, age, sex, and ethnicity, the ILI group weighed (mean ± SE) 6.6 ± 0.7 kg less after 1 y and 5.2 ± 0.7 kg less after 2 y, whereas the DSE group did not change significantly (-0.4 ± 0.6 and -1.0 ± 0.7 kg after 1 and 2 y, respectively; P-interaction < 0.001). Total SM decreased in both groups during year 1 (-1.4 ± 0.2 kg; P < 0.001) with appendicular SM regained during year 2. Liver and spleen masses decreased in the ILI group (-0.12 ± 0.02 and -0.006 ± 0.003 kg, respectively) but were unchanged in the DSE group (0.00 ± 0.02 and 0.004 ± 0.003 kg, respectively). Kidney mass decreased by 0.013 ± 0.003 kg (P < 0.001) over 2 y in both groups.

CONCLUSIONS

Decreases in liver (in Caucasians but not African Americans) and spleen were detected after a 6.2-kg weight reduction compared with a control group. SM and kidney mass decreased in both groups. Appendicular SM was regained during the second year whereas trunk SM was not. No evidence of a disproportionate loss of high-metabolic rate organs (heart, liver, kidney, spleen) compared with SM was found.

The relationship of fasting hyperglycemia to changes in fat and muscle mass after exercise training in type 2 diabetes

AIMS

Exercise training (ET) has been variably associated with body composition changes among persons with type 2 diabetes (T2DM). The degree to which these changes are related to hyperglycemia remains unclear. Our objective was to investigate the relationship of baseline fasting glucose (FG) to the magnitude of muscle gains and fat loss after ET in individuals with T2DM.

METHODS

Participants were enrolled in the SHAPE-2 trial, a six month supervised aerobic and resistance training intervention (three days/week), at Johns Hopkins. This was a post hoc single arm intervention study of participants who completed the exercise intervention (n=50). Participants were aged 40-65years and had T2DM that was not treated with insulin. Body composition was assessed by DEXA.

RESULTS

After 6months of ET, total fat mass decreased (-2.1±3.1kg) and total lean body mass (LBM) increased (0.5±2.0kg) overall, but there was variability among individual participants. There was an increase in % total LBM (1.4±1.9%) and decrease in % total body fat mass (-1.5±2.0%) after ET. Interestingly, each standard deviation (SD) increase in baseline FG (mean=135.5mg/dl; SD=39.0mg/dl) was related to a significant increase in % total LBM (0.54±0.26%, p=0.048) and decrease in % total body fat (-0.57±0.27%, p=0.04) after ET among individual participants.

CONCLUSIONS

Our data demonstrate that muscle gains and fat loss after ET are positively related to baseline hyperglycemia. Further studies are needed to characterize differences in metabolic response following ET among persons with diabetes.

Effects of testosterone treatment on body fat and lean mass in obese men on a hypocaloric diet: a randomised controlled trial

BACKGROUND

Whether testosterone treatment has benefits on body composition over and above caloric restriction in men is unknown. We hypothesised that testosterone treatment augments diet-induced loss of fat mass and prevents loss of muscle mass.

METHODS

We conducted a randomised double-blind, parallel, placebo controlled trial at a tertiary referral centre. A total of 100 obese men (body mass index ≥ 30 kg/m²) with a total testosterone level of or below 12 nmol/L and a median age of 53 years (interquartile range 47-60) receiving 10 weeks of a very low energy diet (VLED) followed by 46 weeks of weight maintenance were randomly assigned at baseline to 56 weeks of 10-weekly intramuscular testosterone undecanoate (n = 49, cases) or matching placebo (n = 51, controls). The main outcome measures were the between-group difference in fat and lean mass by dual-energy X-ray absorptiometry, and visceral fat area (computed tomography).

RESULTS

A total of 82 men completed the study. At study end, compared to controls, cases had greater reductions in fat mass, with a mean adjusted between-group difference (MAD) of -2.9 kg (-5.7 to -0.2; P = 0.04), and in visceral fat (MAD -2678 mm²; -5180 to -176; P = 0.04). Although both groups lost the same lean mass following VLED (cases -3.9 kg (-5.3 to -2.6); controls -4.8 kg (-6.2 to -3.5), P = 0.36), cases regained lean mass (3.3 kg (1.9 to 4.7), P < 0.001) during weight maintenance, in contrast to controls (0.8 kg (-0.7 to 2.3), P = 0.29) so that, at study end, cases had an attenuated reduction in lean mass compared to controls (MAD 3.4 kg (1.3 to 5.5), P = 0.002).

CONCLUSIONS

While dieting men receiving placebo lost both fat and lean mass, the weight loss with testosterone treatment was almost exclusively due to loss of body fat.

TRIAL REGISTRATION

clinicaltrials.gov, identifier NCT01616732 , registration date: June 8, 2012.

Changes in regional body composition over 8 years in a randomized lifestyle trial: The look AHEAD study

OBJECTIVE

To test the hypothesis that an 8-year intensive lifestyle intervention (ILI) suppresses aging-dependent changes in regional lean mass (LM) and fat mass (FM) among people with overweight/obesity and type 2 diabetes.

METHODS

Regional body composition was measured by dual-energy X-ray absorptiometry within a subset of 1,019 volunteers (45-75 years old) in the Look AHEAD study randomized to ILI or diabetes support and education (DSE). The ILI goal was to achieve and maintain ≥7% weight loss through increased physical activity and reduced caloric intake.

RESULTS

Over 8 years, the DSE group exhibited a linear loss of LM and FM. During year 1, the ILI group lost LM and FM. Between years 1 and 8, the ILI group regained most FM in all regions; regional LM converged with that of the DSE group; the percent of LM loss was greater for the leg than for the trunk. Among both groups, regional LM and FM change was proportional to the size of the region, trunk > leg > arm.

CONCLUSIONS

Aging-dependent LM losses, particularly in the leg region, were not suppressed by ILI. The long-term consequences of rapid LM and FM loss and subsequent regain mostly as fat are unknown.

Association of Weight Loss Maintenance and Weight Regain on 4-Year Changes in CVD Risk Factors: the Action for Health in Diabetes (Look AHEAD) Clinical Trial

OBJECTIVE

Short-term weight loss improves cardiovascular disease (CVD) risk factors. We sought to determine the longer-term effects of maintaining weight loss or, conversely, regaining weight.

RESEARCH DESIGN AND METHODS

We used data from Action for Health in Diabetes (Look AHEAD), a randomized trial of intensive lifestyle intervention (ILI) compared to a control condition in overweight/obese individuals with type 2 diabetes. ILI participants were grouped according to weight change patterns, as follows: 1) no weight loss (±3% at years 1 and 4); 2) moderate weight loss (3-8% at years 1 and 4); 3) large weight loss (8-20% at years 1 and 4); 4) moderate loss/full regain (3-8% at year 1/±3% at year 4); 5) large loss/full regain (8-20% at year 1/± 3% year 4); and 6) large loss/partial regain (8-20% at year 1/3-8% at year 4) and changes in CVD risk factors were compared.

RESULTS

Adjusting for baseline differences and medication use, larger weight losses produced greater improvements in HbA1c, systolic blood pressure, HDL cholesterol, and triglycerides at years 1 and 4 (all P ≤ 0.02). Despite maintenance of weight loss, HbA1c levels worsened between years 1 and 4, and remained below baseline only in those with large weight losses. We found no negative associations of losing and regaining weight relative to not having lost weight. Moreover, those who had large initial weight loss but full regain of weight had greater improvements in HbA1c levels at year 4 than those with smaller or no initial weight loss.

CONCLUSIONS

Larger initial weight loss should be encouraged in individuals with type 2 diabetes, despite the possibility of regain.

Legacy effects of short-term intentional weight loss on total body and thigh composition in overweight and obese older adults

Objective:

Weight regain following intentional weight loss may negatively impact body composition, accelerating fat regain and increasing risk of physical disability. The purpose of this study was to compare long-term changes in whole body and thigh composition in obese older adults who intentionally lost and then partially regained weight to obese older adults who remained weight stable.

Subjects/Methods:

This pilot study analyzed total body (dual-energy X-ray absorptiometry (DXA)) and thigh (computed tomography (CT)) composition data collected from 24 older (65–79 years) adults 18 months after completion of a 5-month randomized trial that compared resistance training alone (RT) with RT plus caloric restriction (RT+CR).

Results:

Mean loss of body mass in the RT+CR group (n=13) was 7.1±2.4 kg during the 5-month intervention (74% fat mass; 26% lean mass; all P<0.01), whereas RT (n=11) remained weight stable (+0.3±1.8 kg; P=0.64). Differential group effects were observed for all DXA and CT body composition measures at 5 months (all P⩽0.01); however, by 23 months, group differences persisted only for total body (RT+CR: 81.6±10.0 kg vs RT: 88.5±14.9 kg; P=0.03) and lean (RT+CR: 50.8±9.3 kg vs RT: 54.4±12.0 kg; P<0.01) mass. All RT+CR participants regained weight from 5 to 23 months (mean gain=+4.8±2.6 kg; P<0.01). Total fat mass and all thigh fat volumes increased, whereas thigh muscle volume decreased, during the postintervention follow-up in RT+CR (all P⩽0.01). In the RT group, body mass did not change from 5 to 23 months (−0.2±0.9 kg; P=0.87). Decreased total thigh volume, driven by the loss of thigh muscle volume, were the only postintervention body composition changes observed in the RT group (both P<0.04).

Conclusions:

Short-term body composition benefits of an RT+CR intervention may be lost within 18 months after completion of the intervention.

Caloric restriction for treatment of geriatric obesity: Do the benefits outweigh the risks?

Most evidence for the health benefits of prescribing caloric restriction (CR) for weight loss is derived from randomized, controlled trials (RCTs) in young/middle-aged adults; there are very few RCTs in older adults in which the isolated effects of CR can be deciphered. The purpose of this review is to summarize the RCT evidence of the benefits (and potential risks) of CR for the treatment of obesity in older adults. We identified only 19 published papers from 10 RCTs ranging from 3 to 18 months that met the criteria of independent effects of a CR component and were conducted in adults with a mean age ≥65 yrs. Overall, the results show a beneficial treatment effect for improving some metabolic, functional and body composition outcomes with few documented risks. However, all outcomes were assessed immediately after treatment cessation. Thus, until additional scientifically rigorous evidence with long-term follow-up is available, the risk-to-benefit ratio of CR for the treatment of obesity in older adults remains unclear.