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

•We conducted a randomized controlled trial on 41 obese adults.•We examined effects of weight loss on foot structure and function.•The intervention group lost 4.0 kg more weight than the control group at 3 months.•No significant difference was noted in change in foot structure.•Even modest weight loss yielded a significant reduction in dynamic plantar pressure.

ObjectiveTo investigate the effects of weight reduction on foot structure, gait, and dynamic plantar loading in obese adults.DesignIn 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.Participants41 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/m2.MeasurementsArch 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.ResultsThe 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.ConclusionThis 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.