Effects of weight loss on foot structure and function in obese adults: A pilot randomized controlled trial

Objective: To investigate the effects of weight reduction on foot structure, gait, and dynamic plantar loading in obese adults. Design: In a 3-month randomized-controlled trial, participants were randomized to receive either a weight loss intervention based on portion-controlled meals or a delayed-treatment control. Participants: 41 adults (32 F, 9 M) with a mean +/- SD age of 56.2 +/- 4.7 years and a BMI of 35.9 +/- 4.2 kg/m(2). Measurements: Arch Height Index (AHI), Malleolar Valgus Index (MVI), spatial and temporal gait parameters, plantar peak pressure (PP) and weight were measured at baseline, 3, and 6 months. Results: The intervention group experienced significantly greater weight loss than did the control group (5.9 +/- 4.0 kg versus 1.9 +/- 3.2 kg, p = 0.001) after 3 months. There were no differences between the groups in anatomical foot structure or gait. However, the treatment group showed a significantly reduced PP than the control group beneath the lateral arch and the metatarsals 4 (all p values < .05) at 3 months. The change in PP correlated significantly with the change in weight at the metatarsal 2 (r = 0.57, p = 0.0219), metatarsal 3 (r = 0.56, p = 0.0064) and the medial arch (r = 0.26, p < 0.0001) at 6 months. Conclusion: This was the first RCT designed to assess the effects of weight loss on foot structure, gait, and plantar loading in obese adults. Even a modest weight loss significantly reduced the dynamic plantar loading in obese adults. However, weight loss appeared to have no effects on foot structure and gait. (C) 2014 Elsevier B.V. All rights reserved.