Effect of an 18-month physical activity and weight loss intervention on body composition in overweight and obese older adults

Abstract

Objective Our primary objective was to determine the long-term effects of physical activity (PA) and weight loss (WL) on body composition in overweight/obese older adults. Secondarily, we evaluated the association between change in body mass and composition on change in several cardiometabolic risk factors and mobility. Design and Methods 288 older (X±SD: 67.0±4.8 years), overweight/obese (BMI 32.8±3.8 kg/m2) men and women participated in this 18 month randomized, controlled trial. Treatment groups included PA+WL (n=98), PA-only (n=97), and a successful aging (SA) health education control (n=93). DXA-acquired body composition measures (total body fat and lean mass), conventional biomarkers of cardiometabolic risk, and 400-m walk time were obtained at baseline and 18 months. Results Fat mass was significantly reduced from (X±SE) 36.5±8.9 kg to 31.7±9.0 kg in the PA+WL group (p<0.01), but remained unchanged from baseline in the PA-only (−0.8±3.8 kg) and SA (−0.0±3.9 kg) groups. Lean mass losses were three times greater in the PA+WL group compared to PA-only or SA groups (−2.5±2.8 kg vs. −0.7±2.2 kg or −0.8±2.4 kg, respectively; p<0.01); yet due to a larger decrease in fat mass, percent lean mass was significantly increased over baseline in the PA+WL group (2.1%±2.6%; p<0.01). Fat mass loss was primarily responsible for WL-associated improvements in cardiometabolic risk factors, while reduction in body weight, regardless of compartment, was significantly associated with improved mobility. Conclusion This 18 month PA+WL program resulted in a significant reduction in percent body fat with a concomitant increase in percent body lean mass. Shifts in body weight and composition were associated with favorable changes in clinical parameters of cardiometabolic risk and mobility. Moderate PA without WL had no effect on body composition.

Weight Management in Older Adults

“…Two studies by Beavers and colleagues [35, 36] looked at the effects of a weight loss and physical activity in older adults. In the first study of 271 older adults (mean age of 65.4 years), overall weight loss predicted improvement in mobility disability and walking speed [35].…”

“…Based on this finding, the authors suggest that implies muscle quality, rather than quantity, is important for functional performance in older adults. Two hundred and eighty-eight overweight and obese older adults (mean age of 67.0 years) participated in the second study [36]. During the 12- to 18-month intervention, the physical activity and weight loss group significantly reduced lean and fat mass compared to the physical activity and the weight loss groups, which resulted in a greater percentage of lean mass overall.…”

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

“…This reduced body weight can be maintained for 12–18 months with a continued weight maintenance program in several of the longer-term trials (see Table 1) [38, 40, 46, 48, 51]. Some of the trials examined changes in body composition and, as expected, the CR treatment resulted in greater loss of both fat and lean (muscle) mass compared to control or exercise without CR [42, 45, 47, 48, 51, 53, 56]. …”

“…Data from the RCTs in Table 1 consistently show that a reduction in body weight, achieved through CR either with or without exercise, results in greater loss of lean mass (by DXA) and thigh muscle volume (by CT) compared to control or exercise without CR [45, 48, 51, 53, 54, 56]. Even though absolute lean mass loss can be substantial (up to 4.7 kg in IDEA [51]), in all trials, the majority of total mass lost was fat.…”

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

“…P. Beavers et al, 2014; K. M. Beavers, Ambrosius, Nicklas, & Rejeski, 2013; K. M. Beavers et al, 2014; K.…”