Insulin resistance influences weight loss in non-obese women who followed a home-based exercise program and slight caloric restriction

This study aimed to evaluate the influence of insulin resistance status on weight changes in non-obese women who followed a home-based exercise program and slight caloric restriction over a period of 12 months. Middle-aged (25-45 year), non-obese (body mass index of 23-29.9 kg/m(2)) women were randomly assigned to control (CG) or home-based exercise group (HB). The HB group received a booklet explaining the physical exercises to be practiced at home at least three times per week (40 min/session). Both groups were required to follow a small energy restriction of 100-300 calories per day. For the analysis, women were stratified in two groups according to baseline insulin sensitivity: NIR (non-insulin resistant; n = 121) and IR (insulin resistant; n = 64). Women classified as IR at baseline had greater weight loss after 12 months of follow-up (-1.6 kg vs. -1.1 kg; p = 0.01), and HB exercise helped to reduce weight only among NIR women (-1.5 vs. -0.7; p = 0.04); no differences were observed between intervention groups for IR women (-1.5 vs. -1.7; p = 0.24). There were no differences between IR and NIR groups for lipid profile after adjustment for weight changes. Insulin resistance facilitated weight loss, and home-based exercise promoted greater weight loss only in non-insulin resistance women. (C) 2011 Elsevier Ireland Ltd. All rights reserved.