Physical activity and weight loss in a pragmatic weight loss trial.

The purpose of this study was to determine the association between changes in physical activity and changes in body weight in a cluster-randomized weight loss trial conducted in an underserved population in Louisiana. This study reports analyses conducted in the intervention group only, which was a 24-month multi-component weight loss program delivered by health coaches embedded in primary care clinics. Physical activity was assessed at baseline and at 6, 12, and 24 months of follow-up and changes in body weight were expressed as percent weight change from baseline. Among the sample of 402 patients, percent changes in body weight (mean ± SE) across increasing tertiles of changes in walking between baseline and 24 months were -3.2 ± 1.0%, -5.5 ± 0.9%, and -7.3 ± 0.9%, respectively (p = 0.001). Changes in body weight across increasing tertiles of changes in moderate-to-vigorous-intensity activity between baseline and 24 months were -4.3 ± 1.0%, -5.0 ± 0.9%, and -7.0 ± 0.9%, respectively (p = 0.04). In conclusion, this multi-component intervention resulted in clinically significant weight loss, and greater increases in physical activity over the intervention period were associated with greater percent reductions in body weight. These results are consistent with those from other studies conducted primarily in non-underserved populations.