12 Month Behavioral Weight Loss Intervention With Varying Doses Of Physical Activity

Abstract

Secondary data analysis from intervention studies has suggested that ≥250 min/wk of moderate-to-vigorous physical activity (MVPA) is associated with improved long-term weight loss within the context of a behavioral weight loss intervention; however, randomized clinical trials are needed to support these findings and to determine the feasibility of adults who are overweight or obese to achieve this recommended level of MVPA. PURPOSE: This study examined the ability of a behavioral intervention to achieve MVPA levels recommended for public health (150 min/wk) or weight control (250 min/wk). This study also examine whether weight loss, within the context of a comprehensive weight management program, varied by these prescribed levels of MVPA in adults who were overweight or obese across 12 months. METHODS: Data were examined from sedentary adults (N=230; BMI: 32.1±3.8 kg/m2; age=46.2±7.7 years) enrolled in a behavioral program and randomized to a reduced calorie diet (DIET, N=71), diet plus a moderate dose of MVPA (MOD-EX, N=82), or diet plus a high dose of MVPA (HIGH-EX, N=77). 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. MVPA and weight were assessed at 0, 6, and 12 months. RESULTS: MVPA at 0, 6, and 12 months was 52.3±60.5, 82.3±93.4, and 85.7±110.6 min/wk in DIET; 53.8±78.7, 173.1±112.1, and 185.8±134.5 min/wk in MOD-EX, and 73.2±92.2, 254.1±127.8, and 236.0±154.9 min/wk in HIGH-EX (Group X Time p-value <0.001). Weight significantly decrease in all groups at 6 months (DIET: −9.2±5.8 kg, MOD-EX: −10.2±6.4 kg, HIGH-EX: −9.5±5.4 kg; p<0.001) and 12 months (DIET: −9.7±7.5 kg, MOD-EX: −11.0±8.2 kg, HIGH-EX: −9.7±7.1 kg; p<0.001), with no significant difference between groups. CONCLUSIONS: The MOD-EX and HIGH-EX interventions were successful at achieving the prescribed dose of MVPA in adults with obesity. The lack of additional weight loss with participation in higher amounts of MVPA may suggest that there is a compensatory response in factors influencing energy balance that warrant further investigation. Supported by: NIH (R01 HL103646)