Calorie restriction in overweight older adults: Do benefits exceed potential risks?

The impact of lifestyle-based weight loss in older adults with obesity on muscle and bone health: a balancing act

Despite adverse metabolic and functional consequences of obesity (BMI ≥30 kg/m2), clinical recommendations for weight loss (WL) in older adults (65+ years) with obesity remain controversial. Reluctance stems partly from epidemiologic data demonstrating musculoskeletal tissue loss with WL and increased risk of disability and osteoporotic fracture. Randomized controlled trials in older adults complement and extend knowledge in this area showing: (1) lifestyle-based WL interventions often yield clinically meaningful (~8%-10%) WL in older adults; (2) lean mass loss is significant, although fat mass loss is preferential and physical performance is often improved, particularly when combined with aerobic and resistance training (RT); (3) bone loss is also significant, with some evidence that RT can attenuate WL-associated bone loss; and (4) fat mass regain after intervention cessation is common, yet physical performance gains appear to be maintained. Best practices for treating older adults with obesity include comprehensive assessment of baseline musculoskeletal health; patient-centered goal setting; moderate (i.e., -500 kcal/day) caloric restriction ensuring protein (1-1.2 g/kg/day), calcium (1000-1200 mg/day), and vitamin D (800-1000 IU/day) needs are met; incorporation of RT (≥2 days/week) and moderate-intensity weight-bearing aerobic training (≥150 min/week); and delivery of care by a multidisciplinary team.

The Effects of Different Dietary Patterns on Bone Health

Bone metabolism is a process in which osteoclasts continuously clear old bone and osteoblasts form osteoid and mineralization within basic multicellular units, which are in a dynamic balance. The process of bone metabolism is affected by many factors, including diet. Reasonable dietary patterns play a vital role in the prevention and treatment of bone-related diseases. In recent years, dietary patterns have changed dramatically. With the continuous improvement in the quality of life, high amounts of sugar, fat and protein have become a part of people's daily diets. However, people have gradually realized the importance of a healthy diet, intermittent fasting, calorie restriction, a vegetarian diet, and moderate exercise. Although these dietary patterns have traditionally been considered healthy, their true impact on bone health are still unclear. Studies have found that caloric restriction and a vegetarian diet can reduce bone mass, the negative impact of a high-sugar and high-fat dietary (HSFD) pattern on bone health is far greater than the positive impact of the mechanical load, and the relationship between a high-protein diet (HPD) and bone health remains controversial. Calcium, vitamin D, and dairy products play an important role in preventing bone loss. In this article, we further explore the relationship between different dietary patterns and bone health, and provide a reference for how to choose the appropriate dietary pattern in the future and for how to prevent bone loss caused by long-term poor dietary patterns in children, adolescents, and the elderly. In addition, this review provides dietary references for the clinical treatment of bone-related diseases and suggests that health policy makers should consider dietary measures to prevent and treat bone loss.

Application of the D3 -creatine muscle mass assessment tool to a geriatric weight loss trial: A pilot study

BACKGROUND

Traditionally, weight loss (WL) trials utilize dual energy X-ray absorptiometry (DXA) to measure lean mass. This method assumes lean mass, as the sum of all non-bone and non-fat tissue, is a reasonable proxy for muscle mass. In contrast, the D3 -creatine (D3 Cr) dilution method directly measures whole body skeletal muscle mass, although this method has yet to be applied in the context of a geriatric WL trial. The purpose of this project was to (1) describe estimates of change and variability in D3 Cr muscle mass in older adults participating in an intentional WL intervention and (2) relate its change to other measures of body composition as well as muscle function and strength.

METHODS

The INVEST in Bone Health trial (NCT04076618), used as a scaffold for this ancillary pilot project, is a three-armed, 12-month randomized, controlled trial designed to determine the effects of resistance training or weighted vest use during intentional WL on a battery of musculoskeletal health outcomes among 150 older adults living with obesity. A convenience sample of 24 participants (n = 8/arm) are included in this analysis. At baseline and 6 months, participants were weighed, ingested a 30 mg D3 Cr tracer dose, provided a fasted urine sample 3-6 days post-dosage, underwent DXA (total body fat and lean masses, appendicular lean mass) and computed tomography (mid-thigh and trunk muscle/intermuscular fat areas) scans, and performed 400-m walk, stair climb, knee extensor strength, and grip strength tests.

RESULTS

Participants were older (68.0 ± 4.4 years), mostly White (75.0%), predominantly female (66.7%), and living with obesity (body mass index: 33.8 ± 2.7 kg/m2 ). Six month total body WL was -10.3 (95% confidence interval, CI: -12.7, -7.9) kg. All DXA and computed tomography-derived body composition measures were significantly decreased from baseline, yet D3 Cr muscle mass did not change [+0.5 (95% CI: -2.0, 3.0) kg]. Of muscle function and strength measures, only grip strength significantly changed [+2.5 (95% CI: 1.0, 4.0) kg] from baseline.

CONCLUSIONS

Among 24 older adults, significant WL with or without weighted vest use or resistance training over a 6-month period was associated with significant declines in all bioimaging metrics, while D3 Cr muscle mass and muscle function and strength were preserved. Treatment assignment for the trial remains blinded; therefore, full interpretation of these findings is limited. Future work in this area will assess change in D3 Cr muscle mass by parent trial treatment group assignment in all study participants.

Obesity and Aging

The obesity epidemic in aging populations poses significant public health concerns for greater morbidity and mortality risk. Age-related increased adiposity is multifactorial and often associated with reduced lean body mass. The criteria used to define obesity by body mass index in younger adults may not appropriately reflect age-related body composition changes. No consensus has been reached on the definition of sarcopenic obesity in older adults. Lifestyle interventions are generally recommended as initial therapy; however, these approaches have limitations in older adults. Similar benefits in older compared with younger adults are reported with pharmacotherapy, however, large randomized clinical trials in geriatric populations are lacking.

Support Provided by Caregivers for Community-Dwelling Obesity Individuals: Focus on Elderly and Hispanics

Obesity is a chronic disease marked by the buildup of extra adipose tissue and a higher chance of developing concomitant illnesses such as heart disease, diabetes, high blood pressure, and some malignancies. Over the past few decades, there has been a global increase in the prevalence of obesity, which now affects around one-third of the world's population. According to recent studies, a variety of factors, including genetics and biology as well as environmental, physiological, and psychosocial factors, may have a role in the development of obesity. The prevalence of obesity is often higher among Hispanic American groups than among White people in the U.S. Obesity is a widespread condition with a high risk of morbidity and death, and it is well-recognized that the prevalence of comorbidities rises with rising levels of obesity or body mass index. To combat the rising prevalence of obesity in the USA, especially among Hispanics, one of the fastest-growing racial/ethnic groups in the country, there is an urgent need for obesity therapies. The exact cause of this disparity is unclear, but some responsible factors are a lack of education, high unemployment rates, high levels of food insecurity, an unhealthy diet, inadequate access to physical activity resources, a lack of health insurance, and constricted access to culturally adequate healthcare. Additionally, managing obesity and giving needed/timely support to obese people is a difficult responsibility for medical professionals and their loved ones. The need for caregivers is increasing with the increased number of individuals with obesity, particularly Hispanics. Our article summarizes the status of obesity, focusing on Hispanic populations, and we also highlight specific factors that contribute to obesity, including genetics, epigenetics, biological, physiological, and psychosocial factors, medication and disease, environment, and socio-demographics. This article also reviews caregiver duties and challenges associated with caring for people with obesity.

Effect of exercise modality and weight loss on changes in muscle and bone quality in older adults with obesity

BACKGROUND

Little is known about the effect of exercise modality during a dietary weight loss program on muscle size and quality, as measured by computed tomography (CT). Even less is known about how CT-derived changes in muscle track with changes in volumetric bone mineral density (vBMD) and bone strength.

METHODS

Older adults (66 ± 5 years, 64 % women) were randomized to 18-months of diet-induced weight loss (WL), WL with aerobic training (WL + AT), or WL with resistance training (WL + RT). CT-derived muscle area, radio-attenuation and intermuscular fat percentage at the trunk and mid-thigh were determined at baseline (n = 55) and 18-month follow-up (n = 22-34), and changes were adjusted for sex, baseline value, and weight lost. Lumbar spine and hip vBMD and finite element-derived bone strength were also measured.

RESULTS

After adjustment for the weight lost, muscle area losses at the trunk were -7.82 cm2 [-12.30, -3.35] for WL, -7.72 cm2 [-11.36, -4.07] for WL + AT, and -5.14 cm2 [-8.65, -1.63] for WL + RT (p < 0.001 for group differences). At the mid-thigh, decreases were -6.20 cm2 [-10.39, -2.02] for WL, -7.84 cm2 [-11.19, -4.48] for WL + AT, and -0.60 cm2 [-4.14, 2.94] for WL + RT; this difference between WL + AT and WL + RT was significant in post-hoc testing (p = 0.01). Change in trunk muscle radio-attenuation was positively associated with change in lumbar bone strength (r = 0.41, p = 0.04).

CONCLUSIONS

WL + RT better preserved muscle area and improved muscle quality more consistently than WL + AT or WL alone. More research is needed to characterize the associations between muscle and bone quality in older adults undertaking weight loss interventions.

Protocol for the POMELO (Prevention Of MusclE Loss in Osteoarthritis) randomized pilot feasibility trial

Objective

Individuals with advanced knee osteoarthritis (OA) and a large body size [a body mass index (BMI) ≥35 ​kg/m2] have a higher risk of complications with total knee arthroplasty (TKA), and hence may be ineligible for surgery unless they reduce their BMI. However, pre-TKA weight-loss has not been shown to reduce surgical infection risk and may inadvertently increase risk for muscle loss and development of sarcopenic obesity (low muscle and low strength with higher fat mass). This suggests that a knee OA management approach that doesn't focus on weight change (weight-neutral) may be beneficial. This study examines if a weight-neutral behavioural intervention is feasible and acceptable to participants, and improves muscle mass and physical function in comparison to usual care.

Design

This pilot randomized clinical trial compares a 12-week multimodal intervention [including targeted nutrition, progressive resistance exercise, and arthritis self-management support] to usual care. Co-primary outcomes are feasibility and acceptability, with secondary outcomes of change in lean soft tissue and physical function within and between groups at 3-months and 9-months from baseline. Change in waist circumference, fat mass, blood biomarkers, energy metabolism, OA-related pain and function, health-related quality of life, self-efficacy for arthritis management, and interest in pursuing a TKA within and between groups will be explored.

Conclusion

This study will inform future development of more personalized knee OA treatment approaches for adults with larger bodies. Further, this will contribute to effective alternative treatment pathways that reduce inequities in access to OA care for this understudied patient population.

Estimating heterogeneity of physical function treatment response to caloric restriction among older adults with obesity

Clinical trials conventionally test aggregate mean differences and assume homogeneous variances across treatment groups. However, significant response heterogeneity may exist. The purpose of this study was to model treatment response variability using gait speed change among older adults participating in caloric restriction (CR) trials. Eight randomized controlled trials (RCTs) with five- or six-month assessments were pooled, including 749 participants randomized to CR and 594 participants randomized to non-CR (NoCR). Statistical models compared means and variances by CR assignment and exercise assignment or select subgroups, testing for treatment differences and interactions for mean changes and standard deviations. Continuous equivalents of dichotomized variables were also fit. Models used a Bayesian framework, and posterior estimates were presented as means and 95% Bayesian credible intervals (BCI). At baseline, participants were 67.7 (SD = 5.4) years, 69.8% female, and 79.2% white, with a BMI of 33.9 (4.4) kg/m2. CR participants reduced body mass [CR: -7.7 (5.8) kg vs. NoCR: -0.9 (3.5) kg] and increased gait speed [CR: +0.10 (0.16) m/s vs. NoCR: +0.07 (0.15) m/s] more than NoCR participants. There were no treatment differences in gait speed change standard deviations [CR-NoCR: -0.002 m/s (95% BCI: -0.013, 0.009)]. Significant mean interactions between CR and exercise assignment [0.037 m/s (95% BCI: 0.004, 0.070)], BMI [0.034 m/s (95% BCI: 0.003, 0.066)], and IL-6 [0.041 m/s (95% BCI: 0.009, 0.073)] were observed, while variance interactions were observed between CR and exercise assignment [-0.458 m/s (95% BCI: -0.783, -0.138)], age [-0.557 m/s (95% BCI: -0.900, -0.221)], and gait speed [-0.530 m/s (95% BCI: -1.018, -0.062)] subgroups. Caloric restriction plus exercise yielded the greatest gait speed benefit among older adults with obesity. High BMI and IL-6 subgroups also improved gait speed in response to CR. Results provide a novel statistical framework for identifying treatment heterogeneity in RCTs.

Physiological Systems in Promoting Frailty

Frailty is a complex syndrome affecting a growing sector of the global population as medical developments have advanced human mortality rates across the world. Our current understanding of frailty is derived from studies conducted in the laboratory as well as the clinic, which have generated largely phenotypic information. Far fewer studies have uncovered biological underpinnings driving the onset and progression of frailty, but the stage is set to advance the field with preclinical and clinical assessment tools, multiomics approaches together with physiological and biochemical methodologies. In this article, we provide comprehensive coverage of topics regarding frailty assessment, preclinical models, interventions, and challenges as well as clinical frameworks and prevalence. We also identify central biological mechanisms that may be at play including mitochondrial dysfunction, epigenetic alterations, and oxidative stress that in turn, affect metabolism, stress responses, and endocrine and neuromuscular systems. We review the role of metabolic syndrome, insulin resistance and visceral obesity, focusing on glucose homeostasis, adenosine monophosphate-activated protein kinase (AMPK), mammalian target of rapamycin (mTOR), and nicotinamide adenine dinucleotide (NAD+ ) as critical players influencing the age-related loss of health. We further focus on how immunometabolic dysfunction associates with oxidative stress in promoting sarcopenia, a key contributor to slowness, weakness, and fatigue. We explore the biological mechanisms involved in stem cell exhaustion that affect regeneration and may contribute to the frailty-associated decline in resilience and adaptation to stress. Together, an overview of the interplay of aging biology with genetic, lifestyle, and environmental factors that contribute to frailty, as well as potential therapeutic targets to lower risk and slow the progression of ongoing disease is covered. © 2022 American Physiological Society. Compr Physiol 12:1-46, 2022.

Association of Adherence to a Mediterranean Diet with Excess Body Mass, Muscle Strength and Physical Performance in Overweight or Obese Adults with or without Type 2 Diabetes: Two Cross-Sectional Studies

Overweight and obesity in older adults is associated with disability and is exacerbated by the presence of type 2 diabetes (T2DM). There is emerging evidence that adherence to a Mediterranean diet (MedDiet) reduces adiposity and attenuates physical disability. These cross-sectional studies explored the associations of adherence to a MedDiet with body mass index (BMI), adiposity, muscle strength, and physical performance in older adults without diabetes and in middle-aged or older adults with T2DM. MedDiet adherence was assessed using the Mediterranean Diet Adherence Screener. Fat mass and percent body fat were assessed by dual energy X-ray absorptiometry. Muscle strength was assessed using hand-grip strength, while physical performance was assessed using the Short Physical Performance Battery and gait speed. A total of n = 87 participants with T2DM (T2DM sample: 71.2 ± 8.2 years, BMI: 29.5 ± 5.9) and n = 65 participants without diabetes (non-T2DM sample: 68.7 ± 5.6 years, BMI: 33.7 ± 4.9) were included in these analyses. In the T2DM sample, when controlled for age, gender, and appendicular lean mass index, adherence to a MedDiet was inversely associated with BMI, fat mass, and percent body fat. However, this was no longer maintained in the fully adjusted models. Although, adherence to a MedDiet was positively associated with gait speed (β = 0.155; p = 0.050) independent of all covariates used. Adherence to a MedDiet may be a suitable dietary strategy for preserving lower body physical function in middle-aged and older adults with T2DM. However, these findings should be further investigated using well-designed randomised controlled trials and prospective cohort studies with a wider range of adherence scores to investigate temporal associations.

Age-Related Skeletal Muscle Dysfunction Is Aggravated by Obesity: An Investigation of Contractile Function, Implications and Treatment

Obesity is a global epidemic and coupled with the unprecedented growth of the world's older adult population, a growing number of individuals are both old and obese. Whilst both ageing and obesity are associated with an increased prevalence of chronic health conditions and a substantial economic burden, evidence suggests that the coincident effects exacerbate negative health outcomes. A significant contributor to such detrimental effects may be the reduction in the contractile performance of skeletal muscle, given that poor muscle function is related to chronic disease, poor quality of life and all-cause mortality. Whilst the effects of ageing and obesity independently on skeletal muscle function have been investigated, the combined effects are yet to be thoroughly explored. Given the importance of skeletal muscle to whole-body health and physical function, the present study sought to provide a review of the literature to: (1) summarise the effect of obesity on the age-induced reduction in skeletal muscle contractile function; (2) understand whether obesity effects on skeletal muscle are similar in young and old muscle; (3) consider the consequences of these changes to whole-body functional performance; (4) outline important future work along with the potential for targeted intervention strategies to mitigate potential detrimental effects.

Greater Loss of Central Adiposity from Low-Carbohydrate versus Low-Fat Diet in Middle-Aged Adults with Overweight and Obesity

The objective of this study is to determine whether middle-aged adults prescribed a low carbohydrate-high fat (LCHF) or low fat (LF) diet would have greater loss of central fat and to determine whether the insulin resistance (IR) affects intervention response. A total of 50 participants (52.3 ± 10.7 years old; 36.6 ± 7.4 kg/m2 BMI; 82% female) were prescribed either a LCHF diet (n = 32, carbohydrate: protein: fat of 5%:30%:65% without calorie restriction), or LF diet (n = 18, 63%:13–23%: 10–25% with calorie restriction of total energy expenditure—500 kcal) for 15 weeks. Central and regional body composition changes from dual-x-ray absorptiometry and serum measures were compared using paired t-tests and ANCOVA with paired contrasts. IR was defined as homeostatic model assessment (HOMA-IR) > 2.6. Compared to the LF group, the LCHF group lost more android (15.6 ± 11.2% vs. 8.3 ± 8.1%, p < 0.01) and visceral fat (18.5 ± 22.2% vs. 5.1 ± 15.8%, p < 0.05). Those with IR lost more android and visceral fat on the LCHF verses LF group (p < 0.05). Therefore, the clinical prescription to a LCHF diet may be an optimal strategy to reduce disease risk in middle-aged adults, particularly those with IR.

Use of Metabolomic Profiling to Understand Variability in Adiposity Changes Following an Intentional Weight Loss Intervention in Older Adults

Inter-individual response to dietary interventions remains a major challenge to successful weight loss among older adults. This study applied metabolomics technology to identify small molecule signatures associated with a loss of fat mass and overall weight in a cohort of older adults on a nutritionally complete, high-protein diet. A total of 102 unique metabolites were measured using liquid chromatography-mass spectrometry (LC-MS) for 38 adults aged 65-80 years randomized to dietary intervention and 36 controls. Metabolite values were analyzed in both baseline plasma samples and samples collected following the six-month dietary intervention to consider both metabolites that could predict the response to diet and those that changed in response to diet or weight loss.Eight metabolites changed over the intervention at a nominally significant level: D-pantothenic acid, L-methionine, nicotinate, aniline, melatonin, deoxycarnitine, 6-deoxy-L-galactose, and 10-hydroxydecanoate. Within the intervention group, there was broad variation in the achieved weight-loss and dual-energy x-ray absorptiometry (DXA)-defined changes in total fat and visceral adipose tissue (VAT) mass. Change in the VAT mass was significantly associated with the baseline abundance of α-aminoadipate (p = 0.0007) and an additional mass spectrometry peak that may represent D-fructose, myo-inositol, mannose, α-D-glucose, allose, D-galactose, D-tagatose, or L-sorbose (p = 0.0001). This hypothesis-generating study reflects the potential of metabolomic biomarkers for the development of personalized dietary interventions.

Understanding Dietary Intervention-Mediated Epigenetic Modifications in Metabolic Diseases

The global prevalence of metabolic disorders, such as obesity, diabetes and fatty liver disease, is dramatically increasing. Both genetic and environmental factors are well-known contributors to the development of these diseases and therefore, the study of epigenetics can provide additional mechanistic insight. Dietary interventions, including caloric restriction, intermittent fasting or time-restricted feeding, have shown promising improvements in patients' overall metabolic profiles (i.e., reduced body weight, improved glucose homeostasis), and an increasing number of studies have associated these beneficial effects with epigenetic alterations. In this article, we review epigenetic changes involved in both metabolic diseases and dietary interventions in primary metabolic tissues (i.e., adipose, liver, and pancreas) in hopes of elucidating potential biomarkers and therapeutic targets for disease prevention and treatment.

Forty-eight-hour fasting declines mental flexibility but improves balance in overweight and obese older women

The purpose of this study was to investigate the effects of a 48-h fast on evoked stress, mood, and cognitive and motor functions in overweight and obese older women. Eleven women (body mass index >25 kg/m²) aged 63-80 years were tested under two randomly allocated conditions: 48-h zero-calorie diet with water provided ad libitum and 48-h usual diet. Autonomic function, cortisol levels, mood state, cognitive performance, visuomotor coordination, motor speed, and balance were evaluated before and after each diet. Fasting increased (P < 0.05) cortisol levels, whereas no changes were observed in heart rate and its variability. Fasting increased (P < 0.05) fatigue, prolonged (P < 0.05) reaction time in the two-choice reaction time test and decreased (P < 0.05) the velocity vector of the center of pressure with eyes closed, whereas no changes in performance were observed in the pursuit tracking and finger tapping tests. Thus, although a 48-h fast resulted in greater hypothalamic-pituitary-adrenal axis activity in overweight and obese older women, autonomic nervous system activity was not affected. Fasting increased fatigue and decreased mental flexibility, but improved balance.

Effects of weight loss during a very low carbohydrate diet on specific adipose tissue depots and insulin sensitivity in older adults with obesity: a randomized clinical trial

Background

Insulin resistance and accumulation of visceral adipose tissue (VAT) and intermuscular adipose tissue (IMAT) place aging adults with obesity at high risk of cardio-metabolic disease. A very low carbohydrate diet (VLCD) may be a means of promoting fat loss from the visceral cavity and skeletal muscle, without compromising lean mass, and improve insulin sensitivity in aging adults with obesity.

Objective

To determine if a VLCD promotes a greater loss of fat (total, visceral and intermuscular), preserves lean mass, and improves insulin sensitivity compared to a standard CHO-based/low-fat diet (LFD) in older adults with obesity.

Design

Thirty-four men and women aged 60–75 years with obesity (body mass index [BMI] 30-40 kg/m²) were randomized to a diet prescription of either a VLCD (< 10:25:> 65% energy from CHO:protein:fat) or LFD diet (55:25:20) for 8 weeks. Body composition by dual-energy X-ray absorptiometry (DXA), fat distribution by magnetic resonance imaging (MRI), insulin sensitivity by euglycemic hyperinsulinemic clamp, and lipids by a fasting blood draw were assessed at baseline and after the intervention.

Results

Participants lost an average of 9.7 and 2.0% in total fat following the VLCD and LFD, respectively (p < 0.01). The VLCD group experienced ~ 3-fold greater loss in VAT compared to the LFD group (− 22.8% vs − 1.0%, p < 0.001) and a greater decrease in thigh-IMAT (− 24.4% vs − 1.0%, p < 0.01). The VLCD group also had significantly greater thigh skeletal muscle (SM) at 8 weeks following adjustment for change in total fat mass. Finally, the VLCD had greater increases in insulin sensitivity and HDL-C and decreases in fasting insulin and triglycerides compared to the LFD group.

Conclusions

Weight loss resulting from consumption of a diet lower in CHO and higher in fat may be beneficial for older adults with obesity by depleting adipose tissue depots most strongly implicated in poor metabolic and functional outcomes and by improving insulin sensitivity and the lipid profile.

Trial registration

NCT02760641. Registered 03 May 2016 - Retrospectively registered.

Is Caloric Restriction Associated with Better Healthy Aging Outcomes? A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: Global dietary patterns have gradually shifted toward a 'western type' with progressive increases in rates of metabolic imbalance. Recently, animal and human studies have revealed positive effects of caloric restriction (CR) on many health domains, giving new knowledge for prevention of ill and health promotion; Methods: We conducted a systematic review (SR) of randomized controlled trials (RCTs) investigating the role of CR on health status in adults. A meta-analysis was performed on anthropometric, cardiovascular and metabolic outcomes; Results: A total of 29 articles were retrieved including data from eight RCTs. All included RCTs were at low risk for performance bias related to objective outcomes. Collectively, articles included 704 subjects. Among the 334 subjects subjected to CR, the compliance with the intervention appeared generally high. Meta-analyses proved benefit of CR on reduction of body weight, BMI, fat mass, total cholesterol, while a minor impact was shown for LDL, fasting glucose and insulin levels. No effect emerged for HDL and blood pressure after CR. Data were insufficient for other hormone variables in relation to meta-analysis of CR effects; Conclusion: CR is a nutritional pattern linked to improved cardiometabolic status. However, evidence is limited on the multidimensional aspects of health and requires more studies of high quality to identify the precise impact of CR on health status and longevity.

Calorie Restriction Improves Physical Performance and Modulates the Antioxidant and Inflammatory Responses to Acute Exercise

Our aim was to characterize the effects of calorie restriction on the anthropometric characteristics and physical performance of sportsmen and to evaluate the effects of calorie restriction and acute exercise on mitochondria energetics, oxidative stress, and inflammation. Twenty volunteer taekwondo practitioners undertook a calorie restriction of 30-40% on three alternate days a week for one month. Eleven volunteer sportsmen participated as controls. Both groups performed an energy efficiency test to evaluate physical performance, and samples were taken before and after exercise. The total weight of participants significantly decreased (5.9%) after calorie restriction, while the efficiency of work and the contributions of fat to obtain energy were enhanced by calorie restriction. No significant differences induced by acute exercise were observed in individual non-esterified fatty acid percentage or oxidative stress markers. Calorie restriction downregulated the basal gene expression of nitric oxide synthase, antioxidant enzymes, mitochondrial uncoupling proteins, and repairing stress proteins, but it enhanced the expression of sirtuins in peripheral blood mononuclear cells. In conclusion, one month of calorie restriction decreases body weight and increases physical performance, enhancing energy efficiency, moderating the antioxidant and inflammatory basal gene expression, and influencing its response to acute exercise.

Effect of an Energy-Restricted, Nutritionally Complete, Higher Protein Meal Plan on Body Composition and Mobility in Older Adults With Obesity: A Randomized Controlled Trial

BACKGROUND

Increasing protein content of the diet might be an effective strategy to preserve muscle mass in older adults undergoing caloric restriction, thereby preserving muscle function.

METHODS

Ninety-six older adults (70.3 ± 3.7 years, 74% women, 27% African American) with obesity (35.4 ± 3.3 kg/m2; 47% total body fat) were randomized to a 6-month higher protein (providing 1.2-1.5 g/kg/d) weight loss (WL) program, utilizing the Medifast 4&2&1 Plan, or to weight stability (WS). Dual-energy x-ray absorptiometry-acquired total body mass and composition, and fast gait speed over 400 m was assessed at baseline, 3, and 6 months.

RESULTS

At baseline, dual-energy x-ray absorptiometry-acquired total body, fat, and lean masses were 95.9 ± 14.6, 44.6 ± 7.6, and 48.7 ± 9.5 kg, respectively, and 400-m gait speed was 1.17 ± 0.20 m/s. Total body mass was significantly reduced in the WL group (-8.17 [-9.56, -6.77] kg) compared with the WS group (-1.16 [-2.59, 0.27] kg), with 87% of total mass lost as fat (WL: -7.1 [-8.1, -6.1] kg; -15.9% change from baseline). A differential treatment effect was not observed for change in lean mass (WL: -0.81 [-1.40, -0.23] kg vs WS: -0.24 [-0.85, 0.36] kg). Four-hundred-meter gait speed was also unchanged from baseline although trends suggest slightly increased gait speed in the WL group [0.01 (-0.02, 0.04) m/s] compared with the WS group [-0.02 (-0.05, 0.01) m/s].

CONCLUSION

Intentional weight loss using a high-protein diet is effective in producing significant total body mass and fat mass loss, while helping preserve lean body mass and mobility, in relatively high-functioning older adults with obesity.

Hormesis in Health and Chronic Diseases

'What doesn't kill you makes you stronger'. Hormesis, the paradoxical beneficial effects of low-dose stressors, can be better defined as the biphasic dose-effect or time-effect relationship for any substance. Here we review hormesis-like phenomena in the context of chronic diseases for many substances, including lifestyle factors and endocrine factors. Intermittent or pulsatile exposure can generate opposite effects compared with continuous exposure. An initial exposure can elicit an adaptive stress response with long-lasting protection against subsequent exposures. Early-life stress can increase resilience in later life and lack of stress can lead to vulnerability. Many stressors are naturally occurring and are required for healthy growth or homeostasis, which exemplifies how 'illness is the doorway to health'.

Effect of Weight Change Following Intentional Weight Loss on Bone Health in Older Adults with Obesity

OBJECTIVE

This study aimed to examine change in bone mineral density (BMD) and trabecular bone score among older adult weight regainers (WR) and weight maintainers (WM).

METHODS

Observational data come from 77 older adults (mean age: 67 [SD 5] years; 69% women; 70% white) with obesity (mean BMI: 33.6 [SD  3.7] kg/m² ) who lost weight during an 18-month weight loss intervention. Total body mass and body composition, along with regional (total hip, femoral neck, lumbar spine) BMD and trabecular bone score, were measured at baseline, 18 months, and 30 months. WR (n = 36) and WM (n = 41) categories were defined as a ≥ 5% or < 5% weight gain from 18 to 30 months, respectively.

RESULTS

Among skeletal indices, only total hip BMD was significantly reduced during the 18-month intervention period in both WRs (-3.9%; 95% CI: -5.8% to -2.0%) and WMs (-2.4%; 95% CI: -4.3% to -0.5%; P = 0.07). After adjustment for relevant baseline covariates and weight change from 0 to 18 months, 30-month change in total hip BMD was -2.6% (95% CI: -4.3% to -0.9%) and -3.9% (95% CI: -5.7% to -2.1%) among WRs and WMs, respectively (P = 0.07).

CONCLUSIONS

Loss of hip BMD persists in the year after a weight loss intervention among older adults with obesity, regardless of weight regain status.

Effect of community-based lifestyle interventions on weight loss and cardiometabolic risk factors in obese elderly in China: A randomized controlled trial

PURPOSE

We aimed to assess the effect of community-based lifestyle interventions on weight loss and cardiometabolic risk factors among obese older adults, and to explore the potential factors that impede weight loss during lifestyle interventions.

MATERIALS AND METHODS

A 2-arm parallel randomized controlled trial was conducted from 2013 through 2016 in the community health service centers in Nanjing, China. Four hundred and eighty obese older adults were randomly assigned to receive a 24-month lifestyle intervention (242 participants) or usual care (238 participants). The intervention group received a community-based behavioral lifestyle intervention program, which targeted weight loss through dietary changes and increased physical activity, with a combination mode of intervention delivery.

RESULTS

Weight loss was statistically significant at the end of the intervention with a mean reduction of 0.03 ± 2.51 kg in the control group and 3.22 ± 3.43 kg in the intervention group (p < .001). In the intervention group, 41.1% of participants achieved the target of 5% weight loss significantly (p < .001). Participants in the intervention group had significantly greater improvements in cardiometabolic risk factors. Multivariable logistic regression showed that female, living alone, and having more comorbidities were barriers to weight loss during the intervention.

CONCLUSIONS

This study demonstrated that community-based lifestyle interventions are effective for managing weight and improving cardiometabolic risk factors in obese older adults.

Position of the Academy of Nutrition and Dietetics and the Society for Nutrition Education and Behavior: Food and Nutrition Programs for Community-Residing Older Adults

Given the increasing number and diversity of older adults and the transformation of health care services in the United States, it is the position of the Academy of Nutrition and Dietetics and the Society for Nutrition Education and Behavior that all older adults should have access to evidence-based food and nutrition programs that ensure the availability of safe and adequate food to promote optimal nutrition, health, functionality, and quality of life. Registered dietitian nutritionists and nutrition and dietetics technicians, registered, in partnership with other practitioners and nutrition educators, should be actively involved in programs that provide coordinated services between the community and health care systems that include regular monitoring and evaluation of programming outcomes. The rapidly growing older population, increased demand for integrated continuous support systems, and rising cost of health care underscore the need for these programs. Programs must include food assistance and meal programs, nutritional screening and assessment, nutrition education, medical nutrition therapy, monitoring, evaluation, and documentation of evidence-based outcomes. Coordination with long-term care services and support systems is necessary to allow older adults to remain in their homes; improve or maintain their health and manage chronic disease; better navigate transitions of care; and reduce avoidable hospital, acute, or long-term care facility admissions. Funding of these programs requires evidence of their effectiveness, especially regarding health, functionality, and health care-related outcomes of interest to individuals, caregivers, payers, and policy makers. Targeting of food and nutrition programs involves addressing unmet needs for services, particularly among those at high risk for poor nutrition. Registered dietitian nutritionists and nutrition and dietetics technicians, registered must increase programmatic efforts to measure outcomes to evaluate community-based food and nutrition services. POSITION STATEMENT: It is the position of the Academy of Nutrition and Dietetics and the Society for Nutrition Education and Behavior that older adults should have access to evidence-based food and nutrition programs that ensure the availability of safe and adequate food to promote optimal nutrition, health, functionality, and quality of life. Registered dietitian nutritionists and nutrition and dietetics technicians, registered, in partnership with other practitioners and nutrition educators, should be actively involved in programs that provide coordinated services between the community and health care systems that include regular monitoring and evaluation of programming outcomes. The rapidly growing older population, increased demand for integrated continuous support systems, and rising cost of health care underscore the need for these programs.

The Effects of Time Restricted Feeding on Overweight, Older Adults: A Pilot Study

A growing body of evidence indicates that time restricted feeding (TRF), a popular form of intermittent fasting, can activate similar biological pathways as caloric restriction, the only intervention consistently found to extend healthy lifespan in a variety of species. Thus, TRF may have the potential to also improve function in older adults. Given the challenges many individuals have in following calorie restriction regimens over long-time periods, evaluation of alternative approaches that may produce weight loss and improve function in overweight, older adults is important. Ten overweight, sedentary older adults (≥65 years) at risk for, or with mobility impairments, defined by slow gait speed (<1.0 m/s) participated in this trial. All participants received the intervention and were instructed to fast for approximately 16 h per day over the entire four-week intervention. Outcomes included changes in body weight, waist circumference, cognitive and physical function, health-related quality of life, and adverse events. Adherence levels were high (mean = 84%) based on days goal was met, and mean weight loss was 2.6 kg (p < 0.01). Since body composition was not measured in this study, it is unclear if the observed weight loss was due to loss of fat mass, muscle mass, or the combination of fat and muscle mass. There were no significant changes in other outcomes; however, there were clinically meaningful changes in walking speed and improvements in quality of life, with few reported adverse events. The findings of this pilot study suggest that time restricted feeding is an acceptable and feasible eating pattern for overweight, sedentary older adults to follow.

The complex relationship between diet, quality of life and life expectancy: a narrative review of potential determinants based on data from Italy

The increasing life expectancy at birth and the improvement of general health observed worldwide over the previous years are likely due to many factors. In this regard, the Organisation for Economic Cooperation and Development (OECD) has highlighted the favourable situation of the Italian population, which is amongst the most privileged in the world. In Italy, the national healthcare system is easily accessible to the whole population without direct costs, and alcohol abuse and cigarette smoke are less widespread compared to neighbouring countries. Moreover, the population still largely follows a dietary pattern characterised by the consumption of foods rich in protective compounds (plant foods and their components, such as fibre, polyphenols and polyunsaturated fatty acids). According to recent data, a significant consumption of these foods, which are key components of the Mediterranean model, is likely to play a more important role compared to the limited consumption of nutrients considered less favourable (essentially, saturated fat and sugar). Based on these assumptions, it can be inferred that the adoption of coercive legislative interventions-which have been introduced in other western countries to improve diet quality-may not be an optimal strategy in a country like Italy. Such an intervention would contend with psychological and social aspects (namely with the belief that participating in decision-making is an essential right) and with broader indications emerging in the research within this field (the effectiveness of a nudge approach as opposed to constraining interventions). These factors may limit any expected positive impact on health within this context. LEVEL OF EVIDENCE: Level V, narrative review.

Multidisciplinary Integrated Metabolic Rehabilitation in Elderly Obese Patients: Effects on Cardiovascular Risk Factors, Fatigue and Muscle Performance

Background: Obesity is a widespread problem in the elderly, being associated with severe comorbidities negatively influencing life expectancy. Integrated multidisciplinary metabolic rehabilitation aimed to reduce body weight (BW) and fatigue, increase physical autonomy and introduce healthy life style changes has been proposed as a useful intervention to improve the general health status and quality of life of the obese geriatric population. Methods: Six hundred-eighty four severely obese subjects (F/M = 592/92; age range: 61–83 years; mean body mass index, BMI ± SD: 42.6 ± 5.6 kg/m²) were admitted to take part in a three-week in-hospital BW reduction program (BWRP), entailing energy restricted diet, psychological counselling, physical rehabilitation and nutritional education. Biochemical parameters, cardiovascular risk factors (throughout the Coronary Heart Disease Risk, CHD-R), fatigue (throughout the Fatigue Severity Scale, FSS) and lower limb muscle performance (throughout the Stair Climbing Test, SCT) were evaluated before and at the end of the BWRP. Results: A 4% BW reduction was achieved at the end of the BWRP. This finding was associated with a significant improvement of the metabolic homeostasis (i.e., decrease in total cholesterol and glucose) and a reduction of systolic blood pressure in both females and males, thus resulting in a reduction of CHD-R in the male group. Total FSS score and SCT time decreased in female and male obese patients. The effects of BWPR were comparable among all age-related subgroups (>60, 60–69 and >70 years), apart from ΔCHD-R, which was higher in male subgroups. Finally, age was negatively correlated with ΔBMI and ΔFSS. Conclusions: Though only a relatively limited number of outcomes were investigated, the present study shows that a 4% BW reduction in severely elderly obese patients is associated with positive multisystemic effects, particularly, muscle-skeletal and cardiometabolic benefits, which can favorably influence their general well-being and improve the autonomy level in performing more common daily activities. The maintenance of a healthy life style, including controlled food intake and regular physical activity, after a BWRP is obviously recommended in all elderly obese patients to further improve their clinical condition.

Position of the Academy of Nutrition and Dietetics and the Society for Nutrition Education and Behavior: Food and Nutrition Programs for Community-Residing Older Adults

Given the increasing number and diversity of older adults and the transformation of health care services in the United States, it is the position of the Academy of Nutrition and Dietetics and the Society for Nutrition Education and Behavior that all older adults should have access to evidence-based food and nutrition programs that ensure the availability of safe and adequate food to promote optimal nutrition, health, functionality, and quality of life. Registered dietitian nutritionists and nutrition and dietetics technicians, registered, in partnership with other practitioners and nutrition educators, should be actively involved in programs that provide coordinated services between the community and health care systems that include regular monitoring and evaluation of programming outcomes. The rapidly growing older population, increased demand for integrated continuous support systems, and rising cost of health care underscore the need for these programs. Programs must include food assistance and meal programs, nutritional screening and assessment, nutrition education, medical nutrition therapy, monitoring, evaluation, and documentation of evidence-based outcomes. Coordination with long-term care services and support systems is necessary to allow older adults to remain in their homes; improve or maintain their health and manage chronic disease; better navigate transitions of care; and reduce avoidable hospital, acute, or long-term care facility admissions. Funding of these programs requires evidence of their effectiveness, especially regarding health, functionality, and health care-related outcomes of interest to individuals, caregivers, payers, and policy makers. Targeting of food and nutrition programs involves addressing unmet needs for services, particularly among those at high risk for poor nutrition. Registered dietitian nutritionists and nutrition and dietetics technicians, registered must increase programmatic efforts to measure outcomes to evaluate community-based food and nutrition services.

L-carnitine ameliorated weight loss in fasting therapy: A propensity score-matched study

l-carnitine infusion has been proven to reduce fasting-induced fatigue and hunger in patients with metabolic syndrome in our former study. However, the association between l-carnitine and clinical outcomes of fasting therapy is yet to be investigated. In this study, data from 192 patients who finished fasting therapy from September 2008 to July 2018 were reviewed, among which 142 patients received l-carnitine infusion in fasting regimen. Propensity matching was used to overcome retrospective bias. Patients' anthropometric measurements and metabolic markers were evaluated. After propensity matching, 40 patients were included in each group. Weight (-4.05 ± 1.65 kg vs -3.25 ± 1.68 kg, P = 0.031) and BMI (-1.51±0.61 kg/m² vs -1.20 ± 0.62 kg/m², P = 0.036) decreased in both groups, but significantly more in l-carnitine group, while diastolic blood pressure (-1.67±9.82 mmHg vs -6.21±8.83 mmHg, P = 0.043) and triglycerides (-0.18±0.63 mmol/L vs -1.05±1.70 mmol/L, P = 0.007) decreased significantly more in non-l-carnitine group compared between groups, blood glucose did not differ significantly between groups. l-carnitine can boost the positive effects of fasting therapy on weight loss and maintain the stability of blood pressure.

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.

Therapeutic and lifestyle approaches to obesity in older persons

PURPOSE OF REVIEW

Obesity rates worldwide continue to increase and will disproportionately affect older adults because of population aging. This review highlights recent progress pertaining to therapeutic approaches to obesity in older adults.

RECENT FINDINGS

Caloric restriction alone improves physical function and quality of life in older adults with obesity but is associated with loss of lean mass and increases fracture risk. Adding progressive resistance training to caloric restriction attenuates loss of muscle and bone mass and increasing protein intake enhances this effect. Adding aerobic endurance training to caloric restriction further improves cardiorespiratory fitness but adding both aerobic endurance training and resistance training to caloric restriction results in the greatest improvement in overall physical function while still preserving lean mass. Future promising therapeutic interventions include testosterone, myostatin inhibitors, and bariatric surgery, but there are few studies specific to obese older adults.

SUMMARY

The optimal approach toward obesity in older persons is lifestyle intervention incorporating caloric restriction and exercise consisting of aerobic endurance training and resistance training. Maintenance of adequate protein intake, calcium, and vitamin D is advisable. There is insufficient evidence specific to obese older adults to recommend testosterone or bariatric surgery at this time. Myostatin inhibitors may become a future treatment, and clinical trials are ongoing.

Effect of Exercise Modality During Weight Loss on Bone Health in Older Adults With Obesity and Cardiovascular Disease or Metabolic Syndrome: A Randomized Controlled Trial

The objective of this study was to determine the ability of either aerobic or resistance training to counter weight-loss-associated bone loss in older adults. There were 187 older adults (67 years, 70% women, 64% white) with obesity (BMI = 34.5 ± 3.7 kg/m² ) and cardiovascular disease and/or metabolic syndrome who were randomized to participate in an 18-month, community-based trial, with a follow-up assessment at 30 months. Intervention arms included: weight loss alone (WL; 7% to 10% baseline weight), WL plus aerobic training (WL + AT), and WL plus resistance training (WL + RT), as well as DXA-acquired total hip, femoral neck, and lumbar spine areal bone mineral density (aBMD), and trabecular bone score (TBS). Biomarkers of bone turnover (procollagen type 1 N-terminal propeptide, C-terminal telopeptide of type 1 collagen) were measured at baseline, 6, 18, and 30 (aBMD and TBS only) months. CT-acquired hip and spine volumetric BMD (vBMD), cortical thickness, and bone strength were measured in a subset at baseline (n = 55) and 18 months. Total hip aBMD was reduced by 2% in all groups at 18 months, with a primary analysis showing no significant treatment effects for any DXA, biomarker, or CT outcome. After adjustment for WL and follow-up at 30 months, secondary analyses revealed that total hip [-0.018 (-0.023 to -0.012) g/cm² versus -0.025 (-0.031 to -0.019) g/cm² ; p = 0.05] and femoral neck [-0.01 (-0.009 to 0.008) g/cm² versus -0.011 (-0.020 to -0.002) g/cm² ; p = 0.06] aBMD estimates were modestly attenuated in the WL + RT group compared with the WL group. Additionally, lumbar spine aBMD was increased in the WL [0.015 (0.007 to 0.024) g/cm² ] and the WL + RT [0.009 (0.000 to 0.017) g/cm² ] groups compared with the WL + AT [-0.003 (-0.012 to 0.005)g/cm² ] group; both p ≤ 0.01. Community-based exercise does not prevent bone loss during active WL in older adults; however, adding RT may help minimize long-term hip bone loss. © 2018 American Society for Bone and Mineral Research.

Exploring Factors Associated With Physical Activity in Older Adults: An Ecological Approach

According to ecological models of behavior, the physical environment can influence physical activity engagement by a series of mediating and moderating processes. This study tested such a model to identify factors relevant to older adults' engagement in moderate-vigorous physical activity. Sociodemographic, psychological, physical, and environmental factors were assessed in 432 Western Australians aged 60 and older. Moderate-vigorous physical activity was measured objectively using accelerometers. No environmental variables were related to engagement in moderate-vigorous physical activity either directly or indirectly. However, various individual-level factors were significant, indicating that these may be more important than environmental factors in locations such as Australia that have generally conducive environments and ambient conditions.

Markers of Renal Function in Older Adults Completing a Higher Protein Obesity Intervention and One Year Later: Findings from the MEASUR-UP Trial

Increases in rates of obesity in the older population are hastening the development of chronic illnesses, including chronic kidney disease (CKD). However, obesity reduction in older adults is besought with concerns about the long-term benefit/risk, especially regarding loss of muscle mass and its impact on function. Higher protein intakes have been advocated to help offset the tendency for loss of muscle during weight reduction but this raises concerns about possible negative effects on older kidneys. We assessed markers of renal function in venous blood samples collected during a six-month randomized controlled weight loss trial of higher protein intake in obese (n = 67; BMI ≥ 30 kg/m²) older (≥60 years) adults with physical frailty and age-normal renal status (glomerular filtration rate [GFR] ≥ 45); the Control diet (0.8 g protein/kg body weight/day; n = 21) was compared to a protein-enhanced (1.2 g/g protein/kg body weight/day with 30 g protein/meal; n = 41; Protein) diet. Results showed no group effect of the Protein treatment on markers of renal function (estimated GFR, blood urea nitrogen, and creatinine), either upon intervention completion or one year later. Our findings align with literature support for the benefits of higher protein in the diets of older individuals during obesity reduction and help to confirm the safety of moderate increases in protein intake during weight loss in this population.

Obesity Interventions for Older Adults: Diet as a Determinant of Physical Function

Throughout the world, a high prevalence of obesity in older populations has created a new phenotype of frailty: the obese, functionally frail older adult. The convergence of the obesity epidemic with global graying will undoubtedly increase the prevalence of this concern. Barriers to treatment include ambiguities about the appropriate level of obesity that should trigger an intervention, due to age-related physiologic changes and a lack of consensus on specific criteria and cutoffs. Moreover, obesity interventions for this population have been limited by concerns about negative effects on lean mass, bone mineral density, and even mortality. However, newly reported approaches for restoring physical function by obesity reduction have shown good short-term efficacy. Because the majority of these interventions have used exercise as part of the treatment, this review focuses specifically on current understanding of the discrete effects of dietary interventions for geriatric obesity with regards to functional outcomes on tests including the Short Physical Performance Battery, the Physical Performance Test, and the Western Ontario and McMaster Universities Osteoarthritis Index. The literature showed roughly equal benefits to function from a weight reduction diet or exercise regimen, although neither modality was as efficacious alone as the 2 combined. Only 1 of 3 studies of protein intake during weight loss showed a positive effect of protein on function, but findings to date are too limited to prove or disprove a protein benefit. We conclude that although diet and exercise should be combined whenever possible, it remains important to further investigate the beneficial and likely unique effects that calorie restriction and/or nutrient modification can provide, particularly for obese and functionally frail older populations.

Effects of Calorie Restriction in Obese Older Adults: The CROSSROADS Randomized Controlled Trial

Background

We lack a comprehensive assessment of the risks and benefits of calorie restriction in older adults at high risk for cardiometabolic disease. Calorie restriction may reduce visceral adipose tissue (VAT) but also have negative effects on lean mass and quality of life.

Methods

We conducted a 52-week, randomized controlled trial involving 164 older adults with obesity taking at least one medication for hyperlipidemia, hypertension, or diabetes. Interventions included an exercise intervention alone (Exercise), or with diet modification and body weight maintenance (Maintenance), or with diet modification and energy restriction (Weight Loss). The primary outcome was change in VAT at 12 months. Secondary outcomes included cardiometabolic risk factors, functional status, and quality of life.

Results

A total of 148 participants had measured weight at 12 months. Despite loss of -1.6% ± 0.3% body fat and 4.1% ± 0.7% initial body weight, Weight Loss did not have statistically greater loss of VAT (-192.6 ± 185.2 cm3) or lean mass (-0.4 ± 0.3 kg) compared with Exercise (VAT = -21.9 ± 173.7 cm3; lean mass = 0.3 ± 0.3 kg). Quality of life improved in all groups with no differences between groups. No significant changes in physical function were observed. Weight Loss had significantly greater improvements in blood glucose (-8.3 ± 3.6 mg/dL, p < .05) and HDL-cholesterol (5.3 ± 1.9, p < .01) compared with Exercise. There were no group differences in the frequency of adverse events.

Conclusions

While moderate calorie restriction did not significantly decrease VAT in older adults at high risk for cardiometabolic disease, it did reduce total body fat and cardiometabolic risk factors without significantly more adverse events and lean mass loss.

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.

Aerobic or Resistance Exercise, or Both, in Dieting Obese Older Adults

BACKGROUND

Obesity causes frailty in older adults; however, weight loss might accelerate age-related loss of muscle and bone mass and resultant sarcopenia and osteopenia.

METHODS

In this clinical trial involving 160 obese older adults, we evaluated the effectiveness of several exercise modes in reversing frailty and preventing reduction in muscle and bone mass induced by weight loss. Participants were randomly assigned to a weight-management program plus one of three exercise programs - aerobic training, resistance training, or combined aerobic and resistance training - or to a control group (no weight-management or exercise program). The primary outcome was the change in Physical Performance Test score from baseline to 6 months (scores range from 0 to 36 points; higher scores indicate better performance). Secondary outcomes included changes in other frailty measures, body composition, bone mineral density, and physical functions.

RESULTS

A total of 141 participants completed the study. The Physical Performance Test score increased more in the combination group than in the aerobic and resistance groups (27.9 to 33.4 points [21% increase] vs. 29.3 to 33.2 points [14% increase] and 28.8 to 32.7 points [14% increase], respectively; P=0.01 and P=0.02 after Bonferroni correction); the scores increased more in all exercise groups than in the control group (P<0.001 for between-group comparisons). Peak oxygen consumption (milliliters per kilogram of body weight per minute) increased more in the combination and aerobic groups (17.2 to 20.3 [17% increase] and 17.6 to 20.9 [18% increase], respectively) than in the resistance group (17.0 to 18.3 [8% increase]) (P<0.001 for both comparisons). Strength increased more in the combination and resistance groups (272 to 320 kg [18% increase] and 288 to 337 kg [19% increase], respectively) than in the aerobic group (265 to 270 kg [4% increase]) (P<0.001 for both comparisons). Body weight decreased by 9% in all exercise groups but did not change significantly in the control group. Lean mass decreased less in the combination and resistance groups than in the aerobic group (56.5 to 54.8 kg [3% decrease] and 58.1 to 57.1 kg [2% decrease], respectively, vs. 55.0 to 52.3 kg [5% decrease]), as did bone mineral density at the total hip (grams per square centimeter; 1.010 to 0.996 [1% decrease] and 1.047 to 1.041 [0.5% decrease], respectively, vs. 1.018 to 0.991 [3% decrease]) (P<0.05 for all comparisons). Exercise-related adverse events included musculoskeletal injuries.

CONCLUSIONS

Of the methods tested, weight loss plus combined aerobic and resistance exercise was the most effective in improving functional status of obese older adults. (Funded by the National Institutes of Health; LITOE ClinicalTrials.gov number, NCT01065636 .).

Meal Timing and Frequency: Implications for Cardiovascular Disease Prevention: A Scientific Statement From the American Heart Association

Eating patterns are increasingly varied. Typical breakfast, lunch, and dinner meals are difficult to distinguish because skipping meals and snacking have become more prevalent. Such eating styles can have various effects on cardiometabolic health markers, namely obesity, lipid profile, insulin resistance, and blood pressure. In this statement, we review the cardiometabolic health effects of specific eating patterns: skipping breakfast, intermittent fasting, meal frequency (number of daily eating occasions), and timing of eating occasions. Furthermore, we propose definitions for meals, snacks, and eating occasions for use in research. Finally, data suggest that irregular eating patterns appear less favorable for achieving a healthy cardiometabolic profile. Intentional eating with mindful attention to the timing and frequency of eating occasions could lead to healthier lifestyle and cardiometabolic risk factor management.