Weight loss-induced reduction in physical activity recovers during weight maintenance

Abstract

Background: Weight loss due to a negative energy balance is considered to be accompanied by a decrease in physical activity Objective: The aim of this study was to investigate whether a decrease in physical activity is sustained during weight maintenance Design: Subjects were 20 men and 31 women [mean (6SD) age: 42 6 8 y; BMI (in kg/m2): 31.4 6 2.8]. Weight loss was achieved by an 8-wk very-low-energy diet period, followed by 44 wk of weight maintenance. Physical activity measures were total energy expenditure expressed as a multiple of sleeping metabolic rate (PALSMR) and resting metabolic rate (PALRMR), activity-induced energy expenditure divided by body weight (AEE/kg), and activity counts measured by a triaxial accelerometer. Measurements took place at 0, 8, and 52 wk Results: Body mass decreased significantly during the diet period (10.5 6 3.8%, P , 0.001), and this reduction was sustained after 52 wk (6.0 6 5.1%, P , 0.001). PALSMR and PALRMR decreased from 1.81 6 0.23 and 1.70 6 0.22, respectively, before the diet to 1.69 6 0.20 and 1.55 6 0.19 after the diet (P , 0.001) and increased again after weight maintenance to 1.85 6 0.27 and 1.71 6 0.23, respectively, compared with 8-wk measurements (P , 0.001) AEE/kg decreased from 0.043 6 0.015 MJ/kg at baseline to 0.037 6 0.014 MJ/kg after the diet (P , 0.001) and was higher after 52 wk (0.044 6 0.17 MJ/kg) compared with after 8 wk (P , 0.001). Activity counts decreased from 1.64 6 0.37 megacounts/d at baseline to 1.54 6 0.35 megacounts/d after the diet (P , 0.05) and were higher after 52 wk (1.73 6 0.49 megacounts/d) compared with 8 wk (P , 0.01) Conclusion: A weight loss-induced reduction in physical activity returns to baseline values when weight loss is maintained. © 2013 American Society for Nutrition.