Change in Visceral Adiposity with a 12-Month Behavioral Weight Loss Intervention with Varying Doses of Physical Activity: The Heart Health Study

Abstract

Visceral adipose tissue (VAT) is considered to have biochemical characteristics that influence several pathophysiological processes of the body and high levels are associated with increased risk for metabolic syndrome, cardiovascular disease, and certain cancers. There is data to suggest that supervised aerobic exercise may reduce VAT in the absence of caloric restriction. PURPOSE: To examine whether VAT is reduced within the context of a comprehensive weight management program, varied by prescribed levels of home-based moderate-to-vigorous physical activity (MVPA) in adults who were overweight or obese across 12 months. METHODS: Data were examined from sedentary adults (N=309; BMI: 32.3±3.8 kg/m2; age=45.1±7.9 years) enrolled in a behavioral program and randomized to a reduced calorie diet (DIET, N=107), diet plus a moderate dose of MVPA (MOD-EX, N=101), or diet plus a high dose of MVPA (HIGH-EX, N=101). All groups received weekly intervention sessions in months 1-6 followed by 2 group and 2 telephone contacts per month in months 7-12, and were prescribed a diet to reduce energy intake (1200-1800 kcal/day). MOD-EX was prescribed unsupervised MVPA that progressed to 150 min/wk, whereas HIGH-EX was progressed to 250 min/wk. Body composition and VAT were measured by DXA (GE Lunar iDXA, Corescan) along with weight at 0, 6 and 12 months. RESULTS: Weight significantly decreased in all groups at 6 months (DIET: -9.0±5.9 kg, MOD-EX: -10.2±6.4 kg, HIGH-EX: -9.4±5.3 kg; p<0.001) and 12 months (DIET: -10.0±8.3 kg, MOD-EX: -11.1±8.1 kg, HIGH-EX: -9.7±6.9 kg; p<0.001), with no significant difference between groups. A similar pattern was observed for percent body fat (Baseline: 43.3±5.5%, 6-month: 38.3±7.0%, 12-month: 37.7±7.6%; p<0.001) with no difference between groups. VAT decreased across time (Baseline: 1518±907cm3, 6-month: 1018±617cm3, 12-month: 971±648cm3; p<0.001) with no difference between groups. CONCLUSIONS: The interventions were successful at reducing body weight and improving body composition in adults with obesity. The lack of additional weight loss, reductions in body compositon and VAT with participation in MVPA at two different doses may suggest that there is a compensatory response in factors influencing energy balance that warrant further investigation. Supported by: NIH (R01 HL103646)