Effects of resistance training with and without caloric restriction on physical function and mobility in overweight and obese older adults: a randomized controlled trial

Abstract

Background: Resistance training (RT) improves muscle strength and overall physical function in older adults. RT may be particularly important in the obese elderly who have compromised muscle function. Whether caloric restriction (CR) acts synergistically with RT to enhance function is unknown. Objective: As the primary goal of the Improving Muscle for Functional Independence Trial (I'M FIT), we determined the effects of adding CR for weight loss on muscle and physical function responses to RT in older overweight and obese adults. Design: I'M FIT was a 5-mo trial in 126 older (65-79 y) overweight and obese men and women who were randomly assigned to a progressive, 3-d/wk, moderate-intensity RT intervention with a weightloss intervention (RT+CR) or without a weight-loss intervention (RT). The primary outcome was maximal knee extensor strength; secondary outcomes were muscle power and quality, overall physical function, and total body and thigh compositions. Results: Body mass decreased in the RT+CR group but not in the RT group. Fat mass, percentage of fat, and all thigh fat volumes decreased in both groups, but only the RT+CR group lost lean mass. Adjusted postintervention body-and thigh-composition measures were all lower with RT+CR except intermuscular adipose tissue (IMAT). Knee strength, power, and quality and the 4-m gait speed increased similarly in both groups. Adjusted postintervention means for a 400-m walk time and self-reported disability were better with RT+CR with no group differences in other functional measures, including knee strength. Participants with a lower percentage of fat and IMAT at baseline exhibited a greater improvement in the 400-m walk and knee strength and power. Conclusions: RT improved body composition (including reducing IMAT) and muscle strength and physical function in obese elderly, but those with higher initial adiposity experienced less improvement. The addition of CR during RT improves mobility and does not compromise other functional adaptations to RT. These findings support the incorporation of RT into obesity treatments for this population regardless of whether CR is part of the treatment. This trial was registered at clinicaltrials. gov as NCT01049698.Am J Clin Nutr 2015;101:991-9.

Caloric Restriction for Treatment of Geriatric Obesity: Do the Benefits Outweigh the Risks?

“…Here we summarize the entirety of the published scientific evidence from RCTs comparing a CR treatment to a control group (to allow for isolation of the independent effects of the CR/diet component) that were conducted in adults with a mean age ≥ 65 yrs. We identified 19 published papers from 10 RCTs (Table 1) with a combined sample size of 1981 (range of n=22 to n=585) [38–56]. The treatments ranged from CR alone (achieved through behavioral counseling, meal replacements, or controlled feeding interventions) to CR plus exercise training that were compared to a control group that consisted of usual care (e.g., no intervention) or to an identical exercise training intervention without CR.…”

Central Obesity and Visceral Adipose Tissue Are Not Associated With Incident Atherosclerotic Cardiovascular Disease Events in Older Men

“…Therefore, the risks versus benefit of recommendations to lose weight need to be carefully considered in older men on a case‐by‐case basis. At the least, intentional weight loss in obese very old individuals should be accompanied by appropriate exercise and nutritional interventions to reduce or prevent the loss of lean mass and muscle strength and to preserve functional status 29, 30…”

From Sarcopenia to Frailty: The Pathophysiological Basis and Potential Target Molecules of Intervention

“…Physical exercise, particularly resistance exercise, can improve muscle mass and strength in the elderly [64,65] and obese elderly [58]. Individuals with higher initial adiposity experience less improvement in both muscle strength and physical function [66]. Moreover, the addition of caloric restriction during resistance training improves mobility and does not compromise other functional adaptations to resistance training [66].…”

“…Individuals with higher initial adiposity experience less improvement in both muscle strength and physical function [66]. Moreover, the addition of caloric restriction during resistance training improves mobility and does not compromise other functional adaptations to resistance training [66]. Resistance training also can increase circulating irisin [67] and improve cognitive performance [62].…”