Moderate exercise attenuates the loss of skeletal muscle mass that occurs with intentional caloric restriction-induced weight loss in older, overweight to obese adults

Diet and physical exercise in elderly people with obesity: The state of the art

Obesity is a disease that is assuming pandemic proportions in recent decades. With the advancement of medicine and increased access to care, average survival has increased, resulting in a larger number of elderly people. As a result, the amount of elderly people living with obesity is increasing, and the morbidity and impact of obesity on ageing implies severe limitations for these people. The link between obesity and ageing is not only epidemiological, but also strictly pathophysiological. Obesity accelerates the ageing process and ageing is characterised by pathophysiological mechanisms shared by obesity itself. Some examples of alterations shared by ageing and obesity are metabolic changes, sarcopenia and reduced functional capacity related to both loss of muscle strength and reduced cardiorespiratory fitness, as well as a general reduction in the perception of quality of life. The specific ability to antagonize these mechanisms through non-pharmacological treatment based on nutrition and exercise has always been one of the focal points of the international literature. Therefore, this review provides the state of the art on scientific knowledge regarding the main effects of an adequate nutritional plan and an individualised exercise prescription on the general health of elderly with obesity. In particular, this paper addresses the effect of nutrition and physical exercise on pathophysiological changes peculiar of ageing and obesity, providing also the scientific rational for nutritional and exercise prescription in the population.

Prevalence of sarcopenic obesity in the older non-hospitalized population: a systematic review and meta-analysis

BACKGROUND

Sarcopenic obesity emerges as a risk factor for adverse clinical outcomes in non-hospitalized older adults, including physical disabilities, metabolic diseases, and even mortality. In this systematic review and meta-analysis, we investigated the overall SO prevalence in non-hospitalized adults aged ≥ 65 years and assessed the sociodemographic, clinicobiological, and lifestyle factors related to SO.

METHODS

We searched the PubMed, Embase, Cochrane Library, and Web of Science databases for studies reporting the prevalence of SO from database inception to October 2023. Two researchers independently screened the literature, evaluated the study quality, and extracted the data. Both fixed- and random-effects models were used in the meta-analysis to estimate the pooled SO prevalence and perform subgroup analyses. Publication and sensitivity bias analyses were performed to test the robustness of the associations.

RESULTS

Among 46 studies eligible for review and a total of 71,757 non-hospitalized older adults, the combined prevalence of SO was 14% (95% CI:11-17%, I2 = 99.5%, P < 0.01). Subgroup analysis according to lifestyle factors demonstrated that the SO prevalence was 17% (95% CI: 8-29%, I2 = 99.5%, P < 0.01) in older adults without exercise habits. Regarding clinicobiological factors, older adults with a history of falls (15% [95% CI: 10-22%, I2 = 82%, P < 0.01]), two or more chronic diseases (19% [95% CI: 10-29%, I2 = 97%, P < 0.01]), functional impairment (33% [95% CI: 29-37%, I2 = 0%, P = 0.95]), cognitive impairment (35% [95% CI: 9-65%, I2 = 83%, P = 0.02]), osteoporosis (20% [95% CI: 8-35%, I2 = 96%, P < 0.01]), high fasting glucose level (17% [95% CI: 1-49%, I2 = 98%, P < 0.01]), or the use of antipsychotics (13% [95% CI: 2-28%, I2 = 0%, P = 0.32]) exhibited a higher SO prevalence.

CONCLUSION

SO prevalence is high among non-hospitalized older adults, especially those with functional and cognitive impairments. Thus, SO is a potential problem for the aging population; implementation of planned interventions in the community is needed to reduce the prevalence and adverse outcomes of SO.

Exercise Combined with a Low-Calorie Diet Improves Body Composition, Attenuates Muscle Mass Loss, and Regulates Appetite in Adult Women with High Body Fat Percentage but Normal BMI

BACKGROUND

The present study aimed to examine the effects of a 500 kcal reduction in daily energy intake alone and in combination with 90 min of moderate-to-vigorous aerobic exercise per week on body weight, body composition, and appetite sensations in young women with normal BMI and abnormal body fat percentage.

METHODS

sixty-six young women with normal BMI and abnormal body fat percentage (21.33 ± 1.20 kg/m2 and 34.32 ± 2.94%) were randomly assigned into three groups: (1) caloric restriction (CR; n = 22), (2) caloric restriction with exercise (CR-EX; n = 22), and (3) control (C; n = 22). Data on anthropometry, blood samples, and subjective appetite sensations pre- and post-intervention were collected.

RESULTS

After 4 weeks of intervention, CR and CR-EX groups both reduced body weight, fat percentage, and waist and hip circumferences compared to the C group (p < 0.05). Muscle mass of the CR group was significantly lower than that of the C group (-1.21 ± 0.86 kg vs. -0.27 ± 0.82 kg, p < 0.05), and no significant difference between CR-EX and C groups was observed. For appetite sensations, the subjects of the CR group showed significant increases in change of scores in desire to eat and prospective consumption than that of the C group (p < 0.05), while no significant difference between CR-EX and C groups was observed.

CONCLUSION

A 500 kcal reduction in daily energy intake alone and in combination with 90 min of moderate-to-vigorous aerobic exercise per week could both reduce weight and improve body composition in young adult women with normal BMI and abnormal body fat percentage. More importantly, calorie restriction combined with exercise intervention was superior to calorie restriction alone in improving muscle mass loss and regulating appetite sensations.

The effect of combining nutrient intake and physical activity levels on central obesity, sarcopenia, and sarcopenic obesity: a population-based cross-sectional study in South Korea

BACKGROUND

This study was conducted to investigate the effects of combining nutritional and physical activity (PA) factors on four different categories, according to the presence or absence of sarcopenia and central obesity.

METHODS

From the 2008-2011 Korea National Health and Nutrition Examination Survey, 2971 older adults aged ≥ 65 years were included and divided into four groups based on their sarcopenia and central obesity status: healthy control (39.3%), central obesity (28.9%), sarcopenia (27.4%), and sarcopenic obesity (4.4%). Central obesity was defined as a waist circumference of ≥ 90 cm in men and ≥ 85 cm in women. Sarcopenia was defined as an appendicular skeletal mass index of < 7.0 kg/m2 in men and < 5.4 kg/m2 in women, and sarcopenic obesity was defined as the coexistence of sarcopenia and central obesity.

RESULTS

Participants who consumed more energy and protein than the average requirement had a lower likelihood of having sarcopenia (odds ratio (OR): 0.601, 95% confidence interval (CI): 0.444-0.814) than those who did not consume enough nutrients. The likelihood of central obesity and sarcopenic obesity decreased in groups with recommended PA levels, regardless of whether energy intake met or did not meet the average requirement. Whether PA met or did not meet the recommended level, the likelihood of sarcopenia decreased in groups with energy intake that met the average requirement. However, when PA and energy requirements were met, there was a greater reduction in the likelihood of sarcopenia (OR: 0.436, 95% CI: 0.290-0.655).

CONCLUSION

These findings suggest that adequate energy intake that meets requirements is more likely to be effective as a major prevention and treatment goal for sarcopenia, whereas PA guidelines should be prioritized in the case of sarcopenic obesity.

Association between Different Types of Exercise and Intake of Nutrients including Carbohydrate, Fat, Protein, and B Vitamins in Young Adults

PURPOSE

This cross-sectional study aimed to investigate the association between different types of exercise and nutrient intake to provide a basis for promoting the overall health of young adults.

METHODS

A total of 427 young adults (217 women) aged 21 to 35 were recruited. Participants self-reported time spent (min/week) in endurance exercise, resistance exercise, sports, walking, and other structured physical activity (PA). Nutrient intake was determined via telephone-administered 24 h recalls.

RESULTS

Resistance exercise was positively associated with intake of protein, vitamins B2, B3, B5, B6, and B12 and the percentage of total calories from protein (PCT-PRO), and negatively associated with the percentage of total calories from carbohydrate (PCT-CHO) (p < 0.05). Time spent in aerobic exercise was positively associated with fiber, pectin, and vitamin B6 intake, and negatively associated with PCT-PRO (p < 0.05). Time spent exercising was negatively associated with fiber and pectin intake (p < 0.05). Time spent performing other structured PA was positively associated with pectin intake (p < 0.05). Participants' total exercise time was positively associated with intake of vitamins B2, B5, B12, and PCT-Fat, PCT-PRO, and negatively associated with PCT-CHO (p < 0.05).

CONCLUSION

The results showed an association between various exercise types and specific nutrients. It may be worthwhile to point out the negative association of exercise with CHO intake, which may need to be examined more closely in active young adults. In addition, the supplementation of B vitamins and pectin may be beneficial for their exercise performance and post-exercise recovery.

Muscle plasticity is influenced by renal function and caloric intake through the FGF23-vitamin D axis

Skeletal muscle, the main metabolic engine in the body of vertebrates, is endowed with great plasticity. The association between skeletal muscle plasticity and two highly prevalent health problems: renal dysfunction and obesity, which share etiologic links as well as many comorbidities, is a subject of great relevance. It is important to know how these alterations impact on the structure and function of skeletal muscle because the changes in muscle phenotype have a major influence on the quality of life of the patients. This literature review aims to discuss the influence of a nontraditional axis involving kidney, bone, and muscle on skeletal muscle plasticity. In this axis, the kidneys play a role as the main site for vitamin D activation. Renal disease leads to a direct decrease in 1,25(OH)₂-vitamin D, secondary to reduction in renal functional mass, and has an indirect effect, through phosphate retention, that contributes to stimulate fibroblast growth factor 23 (FGF23) secretion by bone cells. FGF23 downregulates the renal synthesis of 1,25(OH)₂-vitamin D and upregulates its metabolism. Skeletal production of FGF23 is also regulated by caloric intake: it is increased in obesity and decreased by caloric restriction, and these changes impact on 1,25(OH)₂-vitamin D concentrations, which are decreased in obesity and increased after caloric restriction. Thus, both phosphate retention, that develops secondary to renal failure, and caloric intake influence 1,25(OH)₂-vitamin D that in turn plays a key role in muscle anabolism.

Ageing, Metabolic Dysfunction, and the Therapeutic Role of Antioxidants

The gradual ageing of the world population has been accompanied by a dramatic increase in the prevalence of obesity and metabolic diseases, especially type 2 diabetes. The adipose tissue dysfunction associated with ageing and obesity shares many common physiological features, including increased oxidative stress and inflammation. Understanding the mechanisms responsible for adipose tissue dysfunction in obesity may help elucidate the processes that contribute to the metabolic disturbances that occur with ageing. This, in turn, may help identify therapeutic targets for the treatment of obesity and age-related metabolic disorders. Because oxidative stress plays a critical role in these pathological processes, antioxidant dietary interventions could be of therapeutic value for the prevention and/or treatment of age-related diseases and obesity and their complications. In this chapter, we review the molecular and cellular mechanisms by which obesity predisposes individuals to accelerated ageing. Additionally, we critically review the potential of antioxidant dietary interventions to counteract obesity and ageing.

Health effects of the time-restricted eating in adults with obesity: A systematic review and meta-analysis

Background

The number of people suffering from overweight or obesity has been steadily increasing in recent years. As a new form of diet, the efficacy of time-restricted eating (TRE) remains debatable.

Objective

This meta-analysis quantified the effect of TRE on weight change and other physical parameters in obese and overweight adults.

Methods

We did a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing the TRE interventions on weight loss and other metabolic parameters by searching PubMed, Embase, and Cochrane Central Register of Controlled Trials to identify eligible trials published from database inception up until 23 August 2022. The risk of bias was assessed using the Revised Cochrane risk-of-bias tool (ROB-2.0). Meta-analysis was performed using Review Manager 5.4.1 software.

Results

Nine RCTs with 665 individuals (345 in the TRE group while 320 in the control group) were included. Results indicated that TRE had a greater decrease in body weight (-1.28 kg; 95% CI [-2.05, -0.52], p = 0.001), fat mass (-0.72 kg; 95% CI [-1.40, -0.03], p = 0.04), body mass index (-0.34 kg/m²; 95% CI [-0.64, -0.04], p = 0.03) and diastolic blood pressure (-2.26 mmHg 95% CI [-4.02, -0.50], p = 0.01). However, the meta-analysis demonstrated that there was no significant difference between TRE and the control group in lean mass, systolic blood pressure, waist circumference, fasting glucose, fasting insulin, homeostasis model assessment-insulin resistance (HOMA-IR), total cholesterol, high-density lipoprotein, low-density lipoprotein, and triglycerides. Besides, the duration of the study and daily eating window also had an impact on weight change.

Conclusion

TRE was associated with reductions in weight and fat mass and can be a dietary intervention option for adults with obesity. But high-quality trials and longer follow-ups are needed to draw definitive conclusions.

Exercise training enhances muscle mitochondrial metabolism in diet-resistant obesity

Background

Current paradigms for predicting weight loss in response to energy restriction have general validity but a subset of individuals fail to respond adequately despite documented diet adherence. Patients in the bottom 20% for rate of weight loss following a hypocaloric diet (diet-resistant) have been found to have less type I muscle fibres and lower skeletal muscle mitochondrial function, leading to the hypothesis that physical exercise may be an effective treatment when diet alone is inadequate. In this study, we aimed to assess the efficacy of exercise training on mitochondrial function in women with obesity with a documented history of minimal diet-induced weight loss.

Methods

From over 5000 patient records, 228 files were reviewed to identify baseline characteristics of weight loss response from women with obesity who were previously classified in the top or bottom 20% quintiles based on rate of weight loss in the first 6 weeks during which a 900 kcal/day meal replacement was consumed. A subset of 20 women with obesity were identified based on diet-resistance (n=10) and diet sensitivity (n=10) to undergo a 6-week supervised, progressive, combined aerobic and resistance exercise intervention.

Findings

Diet-sensitive women had lower baseline adiposity, higher fasting insulin and triglycerides, and a greater number of ATP-III criteria for metabolic syndrome. Conversely in diet-resistant women, the exercise intervention improved body composition, skeletal muscle mitochondrial content and metabolism, with minimal effects in diet-sensitive women. In-depth analyses of muscle metabolomes revealed distinct group- and intervention- differences, including lower serine-associated sphingolipid synthesis in diet-resistant women following exercise training.

Interpretation

Exercise preferentially enhances skeletal muscle metabolism and improves body composition in women with a history of minimal diet-induced weight loss. These clinical and metabolic mechanism insights move the field towards better personalised approaches for the treatment of distinct obesity phenotypes.

Funding

Canadian Institutes of Health Research (CIHR-INMD and FDN-143278; CAN-163902; CIHR PJT-148634).

Mitochondrial uncoupling attenuates sarcopenic obesity by enhancing skeletal muscle mitophagy and quality control

BACKGROUND

Sarcopenic obesity is a highly prevalent disease with poor survival and ineffective medical interventions. Mitochondrial dysfunction is purported to be central in the pathogenesis of sarcopenic obesity by impairing both organelle biogenesis and quality control. We have previously identified that a mitochondrial-targeted furazano[3,4-b]pyrazine named BAM15 is orally available and selectively lowers respiratory coupling efficiency and protects against diet-induced obesity in mice. Here, we tested the hypothesis that mitochondrial uncoupling simultaneously attenuates loss of muscle function and weight gain in a mouse model of sarcopenic obesity.

METHODS

Eighty-week-old male C57BL/6J mice with obesity were randomized to 10 weeks of high fat diet (CTRL) or BAM15 (BAM15; 0.1% w/w in high fat diet) treatment. Body weight and food intake were measured weekly. Body composition, muscle function, energy expenditure, locomotor activity, and glucose tolerance were determined after treatment. Skeletal muscle was harvested and evaluated for histology, gene expression, protein signalling, and mitochondrial structure and function.

RESULTS

BAM15 decreased body weight (54.0 ± 2.0 vs. 42.3 ± 1.3 g, P < 0.001) which was attributable to increased energy expenditure (10.1 ± 0.1 vs. 11.3 ± 0.4 kcal/day, P < 0.001). BAM15 increased muscle mass (52.7 ± 0.4 vs. 59.4 ± 1.0%, P < 0.001), strength (91.1 ± 1.3 vs. 124.9 ± 1.2 g, P < 0.0001), and locomotor activity (347.0 ± 14.4 vs. 432.7 ± 32.0 m, P < 0.001). Improvements in physical function were mediated in part by reductions in skeletal muscle inflammation (interleukin 6 and gp130, both P < 0.05), enhanced mitochondrial function, and improved endoplasmic reticulum homeostasis. Specifically, BAM15 activated mitochondrial quality control (PINK1-ubiquitin binding and LC3II, P < 0.01), increased mitochondrial activity (citrate synthase and complex II activity, all P < 0.05), restricted endoplasmic reticulum (ER) misfolding (decreased oligomer A11 insoluble/soluble ratio, P < 0.0001) while limiting ER stress (decreased PERK signalling, P < 0.0001), apoptotic signalling (decreased cytochrome C release and Caspase-3/9 activation, all P < 0.001), and muscle protein degradation (decreased 14-kDa actin fragment insoluble/soluble ratio, P < 0.001).

CONCLUSIONS

Mitochondrial uncoupling by agents such as BAM15 may mitigate age-related decline in muscle mass and function by molecular and cellular bioenergetic adaptations that confer protection against sarcopenic obesity.

Effect of Dietary Weight Loss and Macronutrient Intake on Body Composition and Physical Function in Adults with Knee Osteoarthritis: A Systematic Review

Overweight and obesity increase the risk of development and progression of knee osteoarthritis (OA), with higher levels of fat mass and lower levels of lean mass associated with poorer functional status. The aim was to assess changes in weight, body composition and physical function following weight loss or weight maintenance interventions in knee OA. A comprehensive search of four databases was conducted. The risk of bias was assessed using the Quality Criteria Checklist for primary research. Primary outcomes included weight, body composition and physical function; secondary outcomes were lipids, inflammatory biomarkers and muscle strength. Eleven studies were included utilizing diet and exercise (n = 4) or diet-only (n = 7) interventions, two of which were weight maintenance studies. Most studies (n = 10) reported improvements in physical function with significant weight loss, while the change in strength reported in three studies was variable. The diet and exercise studies reported an average reduction in weight of 6.7% and lean mass of 1.6 kg, with greater improvements in physical function. The diet-only studies, including weight maintenance interventions, reported greater average weight loss (7.8%) and reduction in LM (2.0 kg). Overall, better retention of lean mass and muscle strength was observed in participants with higher protein intake (≥37% of energy) and subsequently improved physical function.

Weight Loss and Exercise Differentially Affect Insulin Sensitivity, Body Composition, Cardiorespiratory Fitness, and Muscle Strength in Older Adults With Obesity: A Randomized Controlled Trial

BACKGROUND

Aging-related disease risk is exacerbated by obesity and physical inactivity. It is unclear how weight loss and increased activity improve risk in older adults. We aimed to determine the effects of diet-induced weight loss with and without exercise on insulin sensitivity, VO2peak, body composition, and physical function in older obese adults.

METHODS

Physically inactive older (68.6 ± 4.5 years) obese (body mass index 37.4 ± 4.9 kg/m2) adults were randomized to health education control (HEC; n = 25); diet-induced weight loss (WL; n = 31); or weight loss and exercise (WLEX; n = 28) for 6 months. Insulin sensitivity was measured by hyperinsulinemic-euglycemic clamp, body composition by dual-energy X-ray absorptiometry and MRI, strength by isokinetic dynamometry, and VO2peak by graded exercise test.

RESULTS

WLEX improved (p < .05) peripheral insulin sensitivity (+75 ± 103%) versus HEC (+12 ± 67%); WL (+36 ± 47%) versus HEC did not reach statistical significance. WLEX increased VO2peak (+7 ± 12%) versus WL (-2 ± 24%) and prevented reductions in strength and lean mass induced by WL (p < .05). WLEX decreased abdominal adipose tissue (-16 ± 9%) versus HEC (-3 ± 8%) and intermuscular adipose tissue (-15 ± 13%) versus both HEC (+9 ± 15%) and WL (+2 ± 11%; p < .01).

CONCLUSIONS

Exercise with weight loss improved insulin sensitivity and VO2peak, decreased ectopic fat, and preserved lean mass and strength. Weight loss alone decreased lean mass and strength. Older adults intending to lose weight should perform regular exercise to promote cardiometabolic and functional benefits, which may not occur with calorie restriction-induced weight loss alone.

Is the Peri-Bariatric Surgery Exercise Program Effective in Adults with Obesity: a Systematic Review

The number of people with obesity continues to increase. Bariatric surgery is the most effective treatment for severe obesity. However, this surgery also has disadvantages, such as an increased risk of excessive loss of fat-free mass, lean body mass, and muscle mass compared to other weight loss interventions. PubMed and Cochrane Library database including articles in English, Dutch, French, and German were used. From the 3609 retrieved references, 20 articles were selected. Compared with the control group, physical exercise improved body mass index (5 of 13 articles), weight loss (7 of 17 articles), functional capacity (2 of 5 articles), muscle strength (1 of 1 article), fat-free mass (3 of 5 articles), cardiorespiratory endurance (4 of 6 articles), and quality of life (2 of 4 articles) in obese patients undergoing BS. Current data is suggestive of positive effects of exercise on body mass index, weight loss, functional capacity, muscle strength, fat-free mass, cardiorespiratory endurance, and quality of life in obese patients undergoing bariatric surgery. However, our conclusions are limited because of the heterogeneity of programs and short studies. Further research is needed to determine the most effective physical exercise program in peri-bariatric surgery.

Changes in Body Composition in Older Adults after a Technology-Based Weight Loss Intervention

We conducted a post-hoc analysis of a pre/post, single-arm, non-randomized, multicomponent weight loss intervention in older adults. Fifty-three older adults aged ≥65 with a body mass index ≥ 30 kg/m2 were recruited to participate in a six-month, remote monitoring and video-conferencing delivered, prescriptive intervention consisting of individual and group-led registered dietitian nutrition and physical therapy sessions. We assessed weight, height, and body composition using a SECA 514 bioelectrical impedance analyzer. Mean age was 72.9±3.9 years (70% female) and all had ≥2 chronic conditions. Of those with complete data (n=30), we observed a 4.6±3.5kg loss in weight, 6.1±14.3kg (1.9%) loss in fat mass, and 0.78±1.69L loss in visceral fat (all p<0.05). Fat-free mass (-3.4kg±6.8, p=0.19), appendicular lean mass (-0.25±1.83, p=0.22), and grip strength (+3.46±7.89, p=0.56) did not significantly change. These variables were preserved after stratifying by 5% weight loss. Our intervention led to significant body and visceral fat loss while maintaining fat-free and appendicular lean muscle mass.

Lifestyle indices of body composition and obesity risk and prevalence among multi-ethnic adolescents in Malaysia

The prevalence of childhood obesity in Malaysia has doubled in less than a decade. Moreover, being overweight and obese have been associated with immediate and later comorbidities, thus emphasizing the need to prevent obesity from an early age. This cross-sectional study involved 923 multi-ethnic Malaysian adolescents aged between 15 and 17 years old. Body composition was estimated using bioelectrical impedance analysis. Body mass index (BMI) classification was based on the World Health Organization (WHO) growth reference and the International Obesity Task Force (IOTF) cut-off. Meanwhile, the Child Growth Foundation (CGF) body fat reference was used to classify adolescents' adiposity. Lifestyle indices including physical activity, sedentary behavior, supplement intake, smoking and alcohol status were assessed via questionnaires. A high prevalence of overweight/obesity among the adolescents was observed according to the CGF (26%), followed by that of the WHO (24%) and then the IOTF (23%) cut-off, with high concordance values between each pair. After adjustment, a significant association was found between physical activity (PAQ score) and lean mass (p = 0.027). No lifestyle determinant was found to be a significant predictor of fat percentage. A high sedentary level increased the likelihood of obesity (OR 3.0, p < 0.01), while antioxidant-rich supplements were found to protect against obesity (OR 0.4, p < 0.05). The lifestyle predictors identified in this study may be considered when designing interventions that integrate lifestyle modifications targeting adolescents.

Calorie Restriction With Exercise Intervention Improves Inflammatory Response in Overweight and Obese Adults: A Systematic Review and Meta-Analysis

Background/Purpose: In this systematic review and meta-analysis, we assessed the effects of exercise (EX) combined with calorie restriction (CR) intervention on inflammatory biomarkers, and correlations between biomarkers and participants' characteristics were calculated in overweight and obese adults. Methods: An article search was conducted through PubMed, Web of Science, EMBASE, the Cochrane database, Scopus, and Google Scholar to identify articles published up to April 2021. Studies that examined the effect of EX + CR intervention on inflammatory biomarkers, including C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α), and compared them with a CR trial in overweight and obese adults were included. We calculated the pooled effect by meta-analysis, identified the correlations (between inflammatory biomarkers and participants' characteristics) through meta-regression, and explored the beneficial variable through subgroup analysis. The Cochrane risk of bias tool and Methodological Index for Non-randomized Studies were used to assess the risk of bias for the included trials. Results: A total of 23 trials, including 1196 overweight and obese adults, were included in the meta-analysis. The pooled effect showed that EX + CR intervention significantly decreased CRP levels (P = 0.02), but had no effect on IL-6 (P = 0.62) and TNF-α (P = 0.11). Meta-regression analysis showed that the effect of EX + CR on CRP, IL-6, and TNF-α changes was correlated with lifestyle behavior of adults (Coef. = -0.380, P = 0.018; Coef. = -0.359, P = 0.031; Coef. = -0.424, P = 0.041, respectively), but not with age and BMI. The subgroup analysis results revealed that participants with sedentary lifestyle behavior did not respond to EX + CR intervention, as we found no changes in CRP, IL-6, and TNF-α concentrations (P = 0.84, P = 0.16, P = 0.92, respectively). However, EX + CR intervention significantly decreased CRP (P = 0.0003; SMD = -0.39; 95%CI: -0.60 to -0.18), IL-6 (P = 0.04; SMD = -0.21; 95%CI: -0.40 to -0.01) and TNF-α (P = 0.006; SMD = -0.40, 95%CI: -0.68 to -0.12) in adults without a sedentary lifestyle or with a normal lifestyle. Furthermore, the values between sedentary and normal lifestyle subgroups were statistically significant for CRP, IL-6, and TNF-α. Conclusion: Our findings showed that combination EX + CR intervention effectively decreased CRP, IL-6, and TNF-α in overweight and obese adults with active lifestyles, but not with sedentary lifestyle behavior. We suggest that 'lifestyle behavior' is a considerable factor when designing new intervention programs for overweight or obese adults to improve their inflammatory response.

Weight Loss Strategies and the Risk of Skeletal Muscle Mass Loss

With energy intake restriction and exercise remaining the key diet and lifestyle approaches to weight loss, this is not without potential negative implications for body composition, metabolic health, and quality and quantity of life. Ideally, weight loss should be derived almost exclusively from the fat mass compartment as this is the main driver of metabolic disease, however, several studies have shown that there is an accompanying loss of tissue from the fat-free compartment, especially skeletal muscle. Population groups including post-menopausal women, the elderly, those with metabolic disease and athletes may be particularly at risk of skeletal muscle loss when following a weight management programme. Research studies that have addressed this issue across a range of population groups are reviewed with a focus upon the contribution of resistance and endurance forms of exercise and a higher intake dietary protein above the current guideline of 0.8 g/kg body weight/day. While findings can be contradictory, overall, the consensus appears that fat-free and skeletal muscle masses can be preserved, albeit to varying degrees by including both forms of exercise (but especially resistance forms) in the weight management intervention. Equally, higher intakes of protein can protect loss of these body compartments, acting either separately or synergistically with exercise. Elderly individuals in particular may benefit most from this approach. Thus, the evidence supports the recommendations for intakes of protein above the current guidelines of 0.8 g/kg body weight/d for the healthy elderly population to also be incorporated into the dietary prescription for weight management in this age group.

Evaluation of Measured Resting Metabolic Rate for Dietary Prescription in Ageing Adults with Overweight and Adiposity-Based Chronic Disease

The primary objective of this study was to compare weight changes in two groups of ageing Irish adults with overweight and adiposity-based chronic disease: participants who had dietary energy requirements prescribed on the base of measured RMR and participants whose RMR was estimated by a prediction equation. Fifty-four Caucasian adults (male n = 25; female n = 29, age 57.5 ± 6.3 years, weight 90.3 ± 15.1 kg, height 171.5 ± 9.5 cm, BMI 30.7 ± 4.6 kg/m²) were randomly assigned to a dietary intervention with energy prescription based on either measured RMR or estimated RMR. RMR was measured by indirect calorimetry after an overnight fast and predicted values were determined by the Mifflin et al. (1990) prediction equation. All participants received individual nutritional counselling, motivational interviewing and educational material. Anthropometric variables, blood pressure, blood glucose and blood lipid profile were assessed over 12 weeks. Body weight at week 12 was significantly lower (p < 0.05) for both groups following dietary interventions, mRMR: −4.2%; eRMR: −3.2% of initial body weight. There was no significant difference in weight loss between groups. Overall, 20.8% mRMR and 17.4% of eRMR participants experienced clinically meaningful (i.e., ≥5% of initial weight) weight reduction. Weight reduction in adults aged ≥50 years over the short term (12 weeks) favoured a reduction in blood pressure, triglycerides and glucose, thus reducing cardiovascular disease risk factors. This research indicates that employing a reduced-calorie diet using indirect calorimetry to determine energy needs when improving weight outcomes in adults (>50 years) with overweight and adiposity-based chronic disease is equal to employing a reduced-calorie diet based on the Mifflin et al. (1990) prediction equation. A reduced-energy diet based on mRMR or eRMR facilitates clinically meaningful weight reduction in adults (≥50 years) over the short term (12 weeks) and favours a reduction in blood pressure, triglycerides and glucose, thus reducing cardiovascular disease risk factors. Moreover, the addition of motivational interviewing and behaviour change techniques that support and encourage small behaviour changes is effective in short-term weight management.

Increased 1,25(OH)2-Vitamin D Concentrations after Energy Restriction Are Associated with Changes in Skeletal Muscle Phenotype

The influence of energy restriction (ER) on muscle is controversial, and the mechanisms are not well understood. To study the effect of ER on skeletal muscle phenotype and the influence of vitamin D, rats (n = 34) were fed a control diet or an ER diet. Muscle mass, muscle somatic index (MSI), fiber-type composition, fiber size, and metabolic activity were studied in tibialis cranialis (TC) and soleus (SOL) muscles. Plasma vitamin D metabolites and renal expression of enzymes involved in vitamin D metabolism were measured. In the ER group, muscle weight was unchanged in TC and decreased by 12% in SOL, but MSI increased in both muscles (p < 0.0001) by 55% and 36%, respectively. Histomorphometric studies showed 14% increase in the percentage of type IIA fibers and 13% reduction in type IIX fibers in TC of ER rats. Decreased size of type I fibers and reduced oxidative activity was identified in SOL of ER rats. An increase in plasma 1,25(OH)₂-vitamin D (169.7 ± 6.8 vs. 85.4 ± 11.5 pg/mL, p < 0.0001) with kidney up-regulation of CYP27b1 and down-regulation of CYP24a1 was observed in ER rats. Plasma vitamin D correlated with MSI in both muscles (p < 0.001), with the percentages of type IIA and type IIX fibers in TC and with the oxidative profile in SOL. In conclusion, ER preserves skeletal muscle mass, improves contractile phenotype in phasic muscles (TC), and reduces energy expenditure in antigravity muscles (SOL). These beneficial effects are closely related to the increases in vitamin D secondary to ER.

Current perspectives on obesity and skeletal muscle contractile function in older adults

Obesity has become one of the most pressing public health issues of the 21st century and currently affects a substantial proportion of the older adult population. Although the cardiometabolic complications are well documented, research from the past 20 years has drawn attention to the detrimental effects of obesity on physical performance in older adults. Obesity-related declines in physical performance are due, in part, to compromised muscle strength and power. Recent evidence suggests there are a number of mechanisms potentially underlying reduced whole muscle function, including alterations in myofilament protein function and cellular contractile properties, and these may be related to morphological adaptations, such as shifts in fiber type composition and increased intramyocellular lipid content within skeletal muscle. To date, even less research has focused on how exercise and weight loss interventions for obese older adults affect these mechanisms. In light of this work, we provide an update on the current knowledge related to obesity and skeletal muscle contractile function and highlight a number of questions to address potential etiologic mechanisms as well as intervention strategies, which may help advance our understanding of how physical performance can be improved among obese older adults.

Influence of body mass index and weight lifting on bicep brachii muscle and distal bicep tendon stiffness evaluated using ultrasound elastography

BACKGROUND

This study aimed to investigate the relationship between stiffness of the bicep brachii muscle (BBM) and distal bicep tendon (DBT) and effects of weight lifting (pre- to post-workout changes) among groups with different body mass indexes (BMI).

METHODS

Participants were divided into four groups according to BMI: A, underweight (< 18.5 kg/m²); B, normal (18.5-24.9 kg/m²); C, overweight (25.0-29.9 kg/m²); and D, obese (> 30.0 kg/m²). All participants were males who were untrained and had sedentary lifestyle without involvement in sports activities for the past 12 months. Ultrasonographic measurements to determine muscle and tendon stiffness was performed on the dominant side (i.e., right side) of the upper extremities in all participants.

RESULTS

Twenty-one healthy and untrained males volunteered to participate in this study; 14 were nonsmokers and 7 were smokers. The mean age and BMI were 22.5 ± 1.5 years and 23.8 ± 6.3 kg/m², respectively. Groups A, B, C, and D had four, ten, four, and three participants, respectively. The BBM thickness did not increase with increase in BMI and was not significantly different (P > .05) between groups. The BBM stiffness was significantly different (all P < .05) from pre- to post-workout values in all groups, whereas DBT stiffness did not follow the same trend.

CONCLUSIONS

Our study revealed that the BBM thickness is independent of BMI. After weight lifting, BBM stiffness in groups A and B increased for BBM compared to those in groups C and D. A similar trend was also recorded for DBT. Weight lifting in concentric and eccentric motions affects the stiffness of the BBM and DBT, thus weight lifting plays a role in adjusting the stiffness of the BBM and DBT. Trial registration The study was approved by ethics committee of the College of Applied Medical Sciences (CAMS 080-3839; March 14, 2018).

Influence of Acute and Chronic Exercise on Abdominal Fat Lipolysis: An Update

Exercise is a powerful and effective preventive measure against chronic diseases by increasing energy expenditure and substrate mobilization. Long-duration acute exercise favors lipid mobilization from adipose tissue, i.e., lipolysis, as well as lipid oxidation by skeletal muscles, while chronic endurance exercise improves body composition, facilitates diet-induced weight loss and long-term weight maintenance. Several hormones and factors have been shown to stimulate lipolysis in vitro in isolated adipocytes. Our current knowledge supports the view that catecholamines, atrial natriuretic peptide and insulin are the main physiological stimuli of exercise-induced lipolysis in humans. Emerging evidences indicate that contracting skeletal muscle can release substances capable of remote signaling to organs during exercise. This fascinating crosstalk between skeletal muscle and adipose tissue during exercise is currently challenging our classical view of the physiological control of lipolysis, and provides a conceptual framework to better understand the pleotropic benefits of exercise at the whole-body level.

A Randomized Controlled Trial of Adherence to a 24-Month Home-Based Physical Activity Program and the Health Benefits for Older Adults at Risk of Alzheimer's Disease: The AIBL Active-Study

Background:

Previous studies have demonstrated that physical activity (PA) interventions can improve physical and cognitive outcomes in older adults, but most have been relatively short in duration (<1 year) with a few having specifically targeting individuals at risk of developing Alzheimer’s disease.

Objective:

To examine adherence and physical health outcomes in a 24-month home-based PA intervention in older adults at risk of Alzheimer’s disease.

Methods:

Participants 60 years and older with mild cognitive impairment (MCI) or subjective memory complaints (SMC) with at least 1 cerebrovascular risk factor recruited from The Australian Imaging Biomarkers and Lifestyle Flagship Study of Aging (AIBL) were randomized to a PA or control group (n = 106). The control group continued with their usual lifestyle. The PA group received a 24-month home-based program with a target of 150 minutes/week of moderate PA and a behavioral intervention. Retention (participants remaining) and PA adherence (PA group only, percent PA completed to the PA prescribed) were determined at 6, 12, 18, and 24 months. Assessments at baseline, 6, 12, and 24 months included, PA; fitness; body composition and fat distribution. Key outcome measures were PA adherence and PA.

Results:

The 24-month retention rate (97.2%) and the median PA adherence 91.67% (Q1–Q3, 81.96, 100.00) were excellent. In the long-term the intervention group achieved significantly better improvements in PA levels, leg strength, fat mass and fat distribution compared to the control.

Conclusion:

This study demonstrates that in this target group, long-term PA adherence is achievable and has physical health benefits.

Body Composition Changes Following a Very-Low-Calorie Pre-Operative Diet in Patients Undergoing Bariatric Surgery

BACKGROUND

Fatty liver in obese patients increases the technical difficulty of bariatric surgery. Pre-operative weight loss with a very-low-calorie diet (VLCD) is commonly used to facilitate surgery. Few studies have quantified the systemic effect of rapid pre-operative weight loss on body composition. The objective of this study is to evaluate body composition changes in bariatric surgery patients undergoing a VLCD.

METHODS

Body composition assessments were performed between August 2017 and January 2019 using dual-energy X-ray absorptiometry immediately before and after a 2-week VLCD at St Vincent's Hospital Melbourne. Data collected prospectively pre- and post-VLCD included total body weight, excess body weight, body mass index (BMI), lean body mass (LBM), fat mass (FM) and bone mineral content (BMC). The pre- and post-operative results were compared.

RESULTS

Forty-four patients completed both the 2-week VLCD and body composition assessments. Following a 2-week VLCD, patients lost a mean of 4.5 kg (range - 0.3 to 9.5) in a total body weight and 8.8% (range - 0.9 to 17.1) of excess body weight, with a mean reduction in body mass index of 1.6 kg/m² (range - 0.2 to 3.1). Loss of LBM was 2.8 kg and was significantly greater than loss of FM, 1.7 kg (p < 0.05). BMC changes were insignificant.

CONCLUSION

A VLCD is an effective tool for pre-operative weight reduction. In this cohort, a large amount of the total weight loss was attributed to a loss of lean body mass. The impact of significant lean body mass loss and its relationship to short- and long-term health outcomes warrants further assessment.

Assessment of body composition and impact of sarcopenia and sarcopenic obesity in patients with gastric cancer

Malnutrition is a critical problem in patients with gastric cancer (GC); however, no universally accepted marker that is convenient for clinical use has been defined. Recently, body composition has attracted considerable attention as a means to assess nutrition status in patients with cancer. The clinical role of skeletal muscle mass has also been increasingly recognized. In patients with GC, sarcopenia, which is the loss of skeletal muscle mass, was found to be significantly associated with increased post-surgical complications including hospital stay, healthcare costs, and poor survival. In addition, sarcopenic obesity, which combines the health risks of obesity and sarcopenia, is recognized as a strong risk factor for poor short- and long-term outcomes following gastrectomy. The mechanism linking sarcopenia to worse postoperative outcomes remains unclear; however, skeletal muscle has been found to act as an endocrine organ that produces substances affecting the immune system. In addition, sarcopenia was reported to be associated with toxicity and termination of chemotherapy. Patients with sarcopenia may be unable to react appropriately to the stress of gastrectomy and perioperative chemotherapy. To improve the short- and long-term outcomes of patients with GC and sarcopenia, adequate energy and protein intake are necessary during resistance training. In the present study, we performed a literature review and presented a method to evaluate body composition, the relationship between skeletal muscle mass and GC, and perioperative nutrition and exercise therapy for patients with sarcopenia.

Effect of Weight Loss on Upper Airway Anatomy and the Apnea-Hypopnea Index. The Importance of Tongue Fat

Rationale: Obesity is the primary risk factor for obstructive sleep apnea (OSA). Tongue fat is increased in obese persons with OSA, and may explain the relationship between obesity and OSA. Weight loss improves OSA, but the mechanism is unknown.Objectives: To determine the effect of weight loss on upper airway anatomy in subjects with obesity and OSA. We hypothesized that weight loss would decrease soft tissue volumes and tongue fat, and that these changes would correlate with reductions in apnea-hypopnea index (AHI).Methods: A total of 67 individuals with obesity and OSA (AHI ≥ 10 events/h) underwent a sleep study and upper airway and abdominal magnetic resonance imaging before and after a weight loss intervention (intensive lifestyle modification or bariatric surgery). Airway sizes and soft tissue, tongue fat, and abdominal fat volumes were quantified. Associations between weight loss and changes in these structures, and relationships to AHI changes, were examined.Measurements and Main Results: Weight loss was significantly associated with reductions in tongue fat and pterygoid and total lateral wall volumes. Reductions in tongue fat were strongly correlated with reductions in AHI (Pearson's rho = 0.62, P < 0.0001); results remained after controlling for weight loss (Pearson's rho = 0.36, P = 0.014). Reduction in tongue fat volume was the primary upper airway mediator of the relationship between weight loss and AHI improvement.Conclusions: Weight loss reduced volumes of several upper airway soft tissues in subjects with obesity and OSA. Improved AHI with weight loss was mediated by reductions in tongue fat. New treatments that reduce tongue fat should be considered for patients with OSA.

Impact of energy turnover on fat balance in healthy young men during energy balance, energetic restriction and overfeeding

Body weight control is thought to be improved when physical activity and energy intake are both high (high energy turnover (ET)). The aim of the present study was to investigate the short-term impact of ET on fat balance during zero energy balance (EB), energetic restriction (ER) and overfeeding (OF). In a randomised crossover study, nine healthy men (BMI: 23·0 (SD 2·1) kg/m2, 26·6 (SD 3·5) years) passed 3 × 3 d in a metabolic chamber: three levels of ET (low, medium and high; physical activity level = 1·3-1·4, 1·5-1·6 and 1·7-1·8) were performed at zero EB, ER and OF (100, 75 and 125 % of individual energy requirement). Different levels of ET were obtained by walking (4 km/h) on a treadmill (0, 165 and 330 min). Twenty-four-hour macronutrient oxidation and relative macronutrient balance (oxidation relative to intake) was calculated, and NEFA, 24-h insulin and catecholamine secretion were analysed as determinants of fat oxidation. During EB and OF, 24-h fat oxidation increased with higher ET. This resulted in a higher relative fat balance at medium ET (EB: +17 %, OF: +14 %) and high ET (EB: +23 %, OF: +17 %) compared with low ET (all P < 0·05). In contrast, ER led to a stimulation of 24-h fat oxidation irrespective of ET (no differences in relative fat balance between ET levels, P > 0·05). In conclusion, under highly controlled conditions, a higher ET improved relative fat balance in young healthy men during OF and EB compared with a sedentary state.

Changes in body composition with a hypocaloric diet combined with sedentary, moderate and high-intense physical activity: a randomized controlled trial

BACKGROUND

There is evidence showing the effectiveness of a hypocaloric diet and the increase in physical activity on weight loss. However, the combined role of these factors, not only on weight loss but also body composition, remains unclear. The purpose of this study was to investigate the effect of a hypocaloric diet on the body composition of obese adult women throughout different degrees of physical activity during a weight loss program.

METHODS

One hundred and seventeen healthy female volunteers were randomly assigned to one of the experimental groups: a control group with a low-level prescription of physical activity (1-4 METs), moderate physical activity group that performed 10.000 steps walking (5-8 METs) and intense physical activity group that trained exercises by at least 70% of VO2max three times a week (> 8 METs). All subjects followed a hypocaloric diet designed with a reduction of 500 kcal/day. Nutritional counseling was provided throughout the study period to help ensure dietary adherence.

RESULTS

We found no differences in body weight compared to moderate and intense physical activity (ßstand. = - 0.138 vs. ßstand. = - 0.139). Body fat was lower in women following an intense activity (ßstand. = - 0.436) than those with moderate exercise (ßstand. = - 0.231). The high-intense activity also increased muscle mass at the end of the intervention, standing out above the moderate activity (ßstand. = 0.182 vs. ßstand. = 0.008).

CONCLUSIONS

These findings indicate that a hypocaloric diet, without prescription of physical activity, is adequate to lose weight in the short term (12 weeks), but physical activity is vital to modify the body composition in women with obesity. Body fat was lower when women practiced a moderate exercise compared to hypocaloric diet only, but an intense physical activity was the most effective protocol to obtain a reduction of body fat and maintain muscle mass.

TRIAL REGISTRATION

The study protocol complied with the Declaration of Helsinki for medical studies, it was approved by the bioethical committee of Córdoba University, in the Department of Health at the Regional Government of Andalusia (Act n°284, ref.4156) and retrospectively registered in clinicaltrials.gov (NCT03833791). Registered 2 January 2019.

Benefit-to-Risk Balance of Weight Loss Interventions in Older Adults with Obesity

PURPOSE OF REVIEW

Obesity in the older adult is a burgeoning health epidemic that leads to increased morbidity, disability, and institutionalization. This review presents a brief overview of geriatric-specific consequences of obesity by highlighting the risks and benefits of intentional weight loss.

RECENT FINDINGS

Intentional weight loss reduces the extent of adiposity-related illnesses, yet the approach in older adults is fraught with challenges. Interventions combining caloric restriction and physical exercise (aerobic and resistance) maximize fat loss and minimize loss of muscle and bone. Interventions are also effective at improving physical function, reducing medication burden, and improving symptomatic osteoarthritis in this population. Approaches can mitigate the risks of isolated caloric restriction on muscle and bone in a safe and effective manner. Effective weight loss strategies should be considered in older adults. While there are potential risks, practical clinical approaches can minimize the potential harms while maximizing their benefits.

Feasibility of Weighted Vest Use during a Dietary Weight Loss Intervention and Effects on Body Composition and Physical Function in Older Adults

BACKGROUND

While intentional weight loss in older adults with obesity yields clinically important health benefits there is a need to minimize the negative effects of weight loss on concomitant loss of muscle mass and strength. Data show wearing weighted vests during exercise improves lean mass and lower extremity strength, however the efficacy of wearing a weighted vest during a period of weight loss to mitigate muscle and strength loss is not known.

OBJECTIVES

This study examined the feasibility of daily weighted vest use during a dietary weight loss intervention, and examined effects of vest use on body composition and physical function in well-functioning older adults with obesity.

DESIGN

Randomized, controlled pilot study.

SETTING

Wake Forest Baptist Medical Center in Winston-Salem, NC.

PARTICIPANTS

37 older (age=65-79 yrs), obese (BMI=30-40 kg/ m2) sedentary men and women.

INTERVENTIONS

22-week behavioral diet intervention (targeting 10% weight loss, 1100-1300 kcals/day) with (Diet+Vest; n=20) or without (Diet; n=17) weighted vest use (goal of 10 hours/ day with weight added weekly according to individual loss of body mass).

MEASUREMENTS

Body composition by dual-energy x-ray absorptiometry and measures of physical function, mobility, and muscle strength/power.

RESULTS

Average weighted vest use was 6.7±2.2 hours/day and the vest-wear goal of 10 hrs/day was achieved for 67±22% of total intervention days. Five participants reported adverse events from wearing the vest (all back pain or soreness). Both groups lost a similar amount of weight (Diet= -11.2±4.4 kg; Diet+Vest = -11.0±6.3 kg; p<0.001), with no differences between groups (p=0.25). Fat mass, lean mass, and % body fat decreased significantly (p<0.0001), with no differences between groups. Compared to Diet+Vest, the Diet intervention resulted in greater decreases in leg power (p<0.02), with no other between group differences in physical function.

CONCLUSION

This pilot study showed that vest use during dietary weight loss is feasible and safe in well-functioning older adults with obesity. Larger studies are needed to definitively determine whether external replacement of lost weight during caloric restriction may preserve lower extremity muscle strength and power.

A guide for using NIH Image J for single slice cross-sectional area and composition analysis of the thigh from computed tomography

Reports using computed tomography (CT) to estimate thigh skeletal muscle cross-sectional area and mean muscle attenuation are often difficult to evaluate due to inconsistent methods of quantification and/or poorly described analysis methods. This CT tutorial provides step-by-step instructions in using free, NIH Image J software to quantify both muscle size and composition in the mid-thigh, which was validated against a robust commercially available software, SliceOmatic. CT scans of the mid-thigh were analyzed from 101 healthy individuals aged 65 and older. Mean cross-sectional area and mean attenuation values are presented across seven defined Hounsfield unit (HU) ranges along with the percent contribution of each region to the total mid-thigh area. Inter-software correlation coefficients ranged from R² = 0.92–0.99 for all specific area comparisons measured using the Image J method compared to SliceOmatic. We recommend reporting individual HU ranges for all areas measured. Although HU range 0–100 includes the majority of skeletal muscle area, HU range -29 to 150 appears to be the most inclusive for quantifying total thigh muscle. Reporting all HU ranges is necessary to determine the relative contribution of each, as they may be differentially affected by age, obesity, disease, and exercise. This standardized operating procedure will facilitate consistency among investigators reporting computed tomography characteristics of the thigh on single slice images.

Trial Registration: ClinicalTrials.gov NCT02308228.

Body Composition Changes in Weight Loss: Strategies and Supplementation for Maintaining Lean Body Mass, a Brief Review

With over two-thirds (71.6%) of the US adult population either overweight or obese, many strategies have been suggested for weight loss. While many are successful, the weight loss is often accompanied by a loss in lean body mass. This loss in lean body mass has multiple negative health implications. Therefore, weight loss strategies that protect lean body mass are of value. It is challenging to consume a significant caloric deficit while maintaining lean body mass regardless of macronutrient distribution. Therefore, the efficacy of various dietary supplements on body weight and body composition have been a topic of research interest. Chromium picolinate has been shown to improve body composition by maintaining lean body mass. In this paper we review some common weight loss strategies and dietary supplements with a focus on their impact on body composition and compare them to the effect of chromium picolinate.

Tutorial for using SliceOmatic to calculate thigh area and composition from computed tomography images from older adults

OBJECTIVE

Area of muscle, fat, and bone is often measured in thigh CT scans when tissue composition is a key outcome. SliceOmatic software is commonly referenced for such analysis but published methods may be insufficient for new users. Thus, a quick start guide to calculating thigh composition using SliceOmatic has been developed.

METHODS

CT images of the thigh were collected from older (69 ± 4 yrs, N = 24) adults before and after 12-weeks of resistance training. SliceOmatic was used to segment images into seven density regions encompassing fat, muscle, and bone from -190 to +2000 Hounsfield Units [HU]. The relative contributions to thigh area and the effects of tissue density overlap for skin and marrow with muscle and fat were determined.

RESULTS

The largest contributors to the thigh were normal fat (-190 to -30 HU, 29.1 ± 7.4%) and muscle (35 to 100 HU, 48.9 ± 8.2%) while the smallest were high density (101 to 150 HU, 0.79 ± 0.50%) and very high density muscle (151 to 200 HU, 0.07 ± 0.02%). Training significantly (P<0.05) increased area for muscle in the very low (-29 to -1 HU, 5.5 ± 7.9%), low (0 to 34 HU, 9.6 ± 16.8%), normal (35 to 100 HU, 4.2 ± 7.9%), and high (100 to 150 HU, 70.9 ± 80.6%) density ranges for muscle. Normal fat, very high density muscle and bone did not change (P>0.05). Contributions to area were altered by ~1% or less and the results of training were not affected by accounting for skin and marrow.

CONCLUSIONS

When using SliceOmatic to calculate thigh composition, accounting for skin and marrow may not be necessary. We recommend defining muscle as -29 to +200 HU but that smaller ranges (e.g. low density muscle, 0 to 34 HU) can easily be examined for relationships with the health condition and intervention of interest.

TRIAL REGISTRATION

Clinicaltrials.gov NCT02261961.

Effects of body weight loss program on parameters of muscle performance in female obese adults

BACKGROUND

Body weight loss program may lead to a decrease in lean body mass affecting negatively muscle performance in obese subjects. Thus, the aim of this study was to examine the effect of weight loss on muscle performance in female obese subjects.

METHODS

Eighty obese female adults were enrolled for a 2-month unsupervised aerobic training (UAT) plus nutritional program. In the pre- and postintervention body composition was evaluated by hand-to-foot bioelectrical impedance method, body strength using handgrip test, and lower muscle power was assessed by a 5-repetition chair stand test (CST) and 30-s chair stand test (30sCST) wearing a dynamometer.

RESULTS

Thirty-six subjects completed the protocol, 39% had high compliance (HC), while 61% had low compliance (LC) to exercise prescription. HC group showed a significant decreased body weight, percent of fat mass and lean muscle mass after training. Both groups significantly increased CST performance while only HC significantly increased 30sCST. No differences were found in CST muscle power in both groups between pre- and post-training. However, evaluation of muscle power during 30sCST showed significantly higher value in HC group than LC group after training.

CONCLUSIONS

The results of our study show that although total lean muscle mass decreased after UAT, lower body muscle efficiency increased while muscle power did not change suggesting that in obese patients UAT can help to optimize weight loss and body efficiency. The data might be helpful for exercise professionals to evaluate correctly the muscle performance in obese adults after weight loss programs.

Impact of community lifestyle intervention on anthropometric parameters and body composition among overweight and obese women: findings from the MyBFF@home study

BACKGROUND

The prevalence of overweight and obesity among Malaysian women remained high over the past three decades. Collaboration with existing community at-risk may be feasible for wide-scale prevention of overweight and obesity in the country. The aims of this study were to examine the impact of community-based lifestyle intervention among overweight and obese women on their anthropometric and body composition changes as compared to the usual care group.

METHODS

This was a quasi-experimental study conducted in low-cost flats in Kuala Lumpur, Malaysia. A total of 255 overweight and obesity individuals aged between 18 to 59 years old were assigned to either the lifestyle intervention group (n = 169) or the usual care group (n = 146) over a period of 6 months. Individuals in the intervention group received 6 individual lifestyle counselling comprised of physical activity, diet counselling and self-monitoring components aimed to achieve at least 5% weight loss while individuals in the usual care group obtained six sessions of health care seminars from health care providers. These individuals were then followed-up for another 6 months without any intervention as part of maintenance period.

RESULTS

An intention-to-treat analysis of between-groups at 6-month of intervention (β, 95% CI) revealed greater changes in weight among intervention individuals' (- 1.09 kg vs. -0.99; p < 0.018) as compared to the control group. These changes were not sustained during the maintenance phase (between 6 and 12 months). Overall significant improvement at 12th month was found for visceral fat (- 0.78 vs. -0.64; p-value = 0.017), although no significant changes between groups were detected either during intervention or maintenance phase (p > 0.05). Individuals in the intervention group showed a significant increase for skeletal muscle mass (0.13 kg) than those individuals in the control group (- 0.37 kg), p = 0.033, throughout the study period.

CONCLUSION

This study provides evidence that an overweight and obesity prevention program can be implemented in a community setting, with some reduction of several anthropometric and body composition parameters.

ESPEN guideline on clinical nutrition and hydration in geriatrics

BACKGROUND

Malnutrition and dehydration are widespread in older people, and obesity is an increasing problem. In clinical practice, it is often unclear which strategies are suitable and effective in counteracting these key health threats.

AIM

To provide evidence-based recommendations for clinical nutrition and hydration in older persons in order to prevent and/or treat malnutrition and dehydration. Further, to address whether weight-reducing interventions are appropriate for overweight or obese older persons.

METHODS

This guideline was developed according to the standard operating procedure for ESPEN guidelines and consensus papers. A systematic literature search for systematic reviews and primary studies was performed based on 33 clinical questions in PICO format. Existing evidence was graded according to the SIGN grading system. Recommendations were developed and agreed in a multistage consensus process.

RESULTS

We provide eighty-two evidence-based recommendations for nutritional care in older persons, covering four main topics: Basic questions and general principles, recommendations for older persons with malnutrition or at risk of malnutrition, recommendations for older patients with specific diseases, and recommendations to prevent, identify and treat dehydration. Overall, we recommend that all older persons shall routinely be screened for malnutrition in order to identify an existing risk early. Oral nutrition can be supported by nursing interventions, education, nutritional counseling, food modification and oral nutritional supplements. Enteral nutrition should be initiated if oral, and parenteral if enteral nutrition is insufficient or impossible and the general prognosis is altogether favorable. Dietary restrictions should generally be avoided, and weight-reducing diets shall only be considered in obese older persons with weight-related health problems and combined with physical exercise. All older persons should be considered to be at risk of low-intake dehydration and encouraged to consume adequate amounts of drinks. Generally, interventions shall be individualized, comprehensive and part of a multimodal and multidisciplinary team approach.

CONCLUSION

A range of effective interventions is available to support adequate nutrition and hydration in older persons in order to maintain or improve nutritional status and improve clinical course and quality of life. These interventions should be implemented in clinical practice and routinely used.

A randomised controlled intervention study investigating the efficacy of carotenoid-rich fruits and vegetables and extra-virgin olive oil on attenuating sarcopenic symptomology in overweight and obese older adults during energy intake restriction: protocol paper

Background

Weight loss interventions have not been advocated for overweight/obese older adults due to potential loss of skeletal muscle and strength impacting on physical function with potential loss of independence. Carotenoids and polyphenols are inversely associated with sarcopenic symptomology. This paper reports the protocol of a study evaluating the efficacy of a high-protein, energy restricted diet rich in carotenoids and polyphenols on body composition, muscle strength, physical performance and quality of life in overweight and obese older adults.

Methods

This randomised controlled clinical trial will recruit community-dwelling, healthy overweight and obese older adults (≥60 years) for a 12-week weight loss intervention. Seventy-three participants will be recruited and randomized to an energy restricted (~30% restriction), isocaloric diet (30% protein; 30% carbohydrate; 40% fat) enriched with either: a) 375 g/d of high carotenoid vegetables, 300 g/d high carotenoid fruit, and 40-60 ml extra-virgin olive oil (EVOO); or b) 375 g/d of lower carotenoid vegetables, 300 g/d lower carotenoid fruit, and 40-60 ml Polyunsaturated fatty acid (PUFA) based oil. All participants will receive individual dietary counselling each fortnight for the duration of the study and will be asked to maintain their habitual level of physical activity throughout the study. The primary outcome will be appendicular skeletal muscle (ASM) assessed by dual energy X-ray absorptiometry (DXA). Secondary outcomes will include body weight, fat-free mass (FFM), fat mass (FM), muscle strength (Isometric hand-grip strength), physical performance (Short Physical Performance Battery), physical activity (International Physical Activity Questionnaire) and health related quality of life (SF-36). Outcomes will be measured at baseline and at week 12.

Discussion

The results of this study will provide a novel insight relating to the potential influence of high carotenoid and polyphenol intakes on attenuation of ASM during dietary energy-restricted weight loss in overweight and obese older adults.

Trial registration

The trial was registered on the Australia New Zealand Clinical Trials Register (ACTRN12616001400459); Trial registration date: 10th October, 2016.

Weight Loss Strategies in the Elderly: A Clinical Conundrum

The age-related concomitant loss of skeletal muscle and accumulation of excess adipose tissue have been commonly referred to as sarcopenic obesity. While weight loss may help mitigate the metabolic abnormalities linked to obesity, low fitness levels and muscle atrophy complicate the effectiveness of lifestyle interventions. Because of low levels of compliance, suboptimal economic efficiency, and low functional capacity, there has been no consensus on optimal therapy. This includes the use of high-protein diets that do not ensure muscle preservation during weight loss in this segment of the population. The primary objectives of this review are to discuss the relevance of sarcopenic obesity, examine the feasibility of weight loss in the elderly, and highlight new approaches to the problem.

Weight reduction does not induce an undesirable decrease in muscle mass, muscle strength, or physical performance in men with obesity: a pilot study

PURPOSE

To date, there have been no reports on whether weight reduction causes decreases in muscle mass, muscle strength, or physical performance that could lead to health problems. Thus, in this pilot study, we investigated the appropriateness of the changes in muscle mass, muscle strength and physical performance after weight reduction.

METHODS

Obese men who completed a weight reduction program to decrease and maintain a body mass index (BMI) of less than 25 kg/m2 for one year were recruited for the study. One year after the completion of a weight reduction program, the participants' muscle mass, muscle strength, and physical performance were compared with those in a reference group composed of individuals whose BMI was less than 25 kg/m2. Whole-body scanning was performed using dual-energy X-ray absorptiometry to analyze muscle mass. Handgrip strength and knee extensor strength were measured to evaluate arm and leg muscle strength, respectively. For physical performance, a jump test was employed.

RESULTS

The results showed that the biceps, triceps, subscapular, and suprailiac areas of professional fashion models were significantly thinner than those of women in general (p<.001), and that their waist size was also significantly smaller (p<.001). However, hip circumference showed no significant difference. Body mass index, waist-to-hip ratio, and body fat (%) in professional fashion models were significantly lower than those in women in general (p<.001), while the body density in professional fashion models was significantly greater (p<0.001).

CONCLUSION

Weight reduction participants showed an average reduction in body weight of -16.47%. Normalized arm muscle mass and handgrip strength were significantly greater in the weight reduction group than in the reference group; however, no significant differences were detected between the two groups with respect to the other variables. After one year, there were no significant differences between the two groups.

Calorie Restriction-induced Weight Loss and Exercise Have Differential Effects on Skeletal Muscle Mitochondria Despite Similar Effects on Insulin Sensitivity

Background

Skeletal muscle insulin resistance and reduced mitochondrial capacity have both been reported to be affected by aging. The purpose of this study was to compare the effects of calorie restriction-induced weight loss and exercise on insulin resistance, skeletal muscle mitochondrial content, and mitochondrial enzyme activities in older overweight to obese individuals.

Methods

Insulin-stimulated rates of glucose disposal (Rd) were determined using the hyperinsulinemic euglycemic clamp before and after completing 16 weeks of either calorie restriction to induce weight loss (N = 7) or moderate exercise (N = 10). Mitochondrial volume density, mitochondria membrane content (cardiolipin), and activities of electron transport chain (rotenone-sensitive NADH-oxidase), tricarboxylic acid (TCA) cycle (citrate synthase) and β-oxidation pathway (β-hydroxyacyl CoA dehydrogenase; β-HAD) were measured in percutaneous biopsies of the vastus lateralis before and after the interventions.

Results

Rd improved similarly (18.2% ± 9.0%, p < .04) with both weight loss and exercise. Moderate exercise significantly increased mitochondrial volume density (14.5% ± 2.0%, p < .05), cardiolipin content (22.5% ± 13.4%, p < .05), rotenone-sensitive NADH-oxidase (65.7% ± 13.2%, p = .02) and β-HAD (30.7% ± 6.8%, p ≤ .03) activity, but not citrate synthase activity (10.1% ± 4.0%). In contrast, calorie restriction-induced weight loss did not affect mitochondrial content, NADH-oxidase or β-HAD, yet increased citrate synthase activity (44.1% ± 21.1%, p ≤ .04). Exercise (increase) or weight loss (decrease) induced a remodeling of cardiolipin with a small (2%-3%), but significant change in the relative content of tetralinoleoyl cardiolipin.

Conclusion

Exercise increases both mitochondria content and mitochondrial electron transport chain and fatty acid oxidation enzyme activities within skeletal muscle, while calorie restriction-induced weight loss did not, despite similar improvements in insulin sensitivity in overweight older adults.

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.

The Impact of a Weight Loss Intervention on Diet Quality and Eating Behaviours in People with Obesity and COPD

There is a paucity of evidence to guide clinicians about appropriate management strategies for people with obesity and Chronic Obstructive Pulmonary Disease (COPD). We have recently published results from the first weight loss intervention in adults (>18 years) with obesity (body mass index; BMI ≥ 30 kg/m²) and COPD, using a low-calorie diet coupled with a partial meal replacement plan and resistance exercise training, which resulted in a 6.4% reduction in weight while maintaining skeletal muscle mass and improving health status. This sub-study aims to evaluate the intervention by (a) examining changes in dietary intake and nutritional biomarkers and (b) examining predictors of weight loss. Dietary intake was evaluated using four-day food diaries, and analysis of plasma fatty acids and plasma carotenoids as biomarkers of dietary fat intake and fruit and vegetable intake, respectively. Twenty-eight obese COPD subjects (n = 17 males, n = 11 females) with a mean (standard deviation; SD) age of 67.6 (6.3) years completed the 12-week weight loss intervention. Pre-intervention, mean (SD) BMI was 36.3 (4.6) kg/m². Micronutrient intake improved from pre- to post-intervention, with the percentage of subjects meeting the Nutrient Reference Values increased for all micronutrients. Post-intervention, significant decreases in total (p = 0.009) and saturated fat intake (p = 0.037), and corresponding decreases in total (p = 0.007) and saturated plasma fatty acids (p = 0.003) were observed. There was a trend towards higher total carotenoids post-intervention (p = 0.078). Older age (p = 0.025), higher pre-intervention uncontrolled eating (p < 0.001) and plasma carotenoids (p = 0.009) predicted weight loss. This demonstrates the efficacy of a weight loss intervention in improving diet quality of obese COPD adults.