Dietary restriction and walking reduce fat deposition in the midthigh in obese older women

Abstract

Background: It is suggested that fat deposition within midthigh muscle, represented by low-density lean tissue, increases with deconditioning and obesity and is associated with risk factors for cardiovascular disease (CVD) in women. Objective: We determined the effects of a 6-mo weight loss and walking (3 times/wk) program (WL+AEX) on midthigh low-density lean tissue and glucose and lipid metabolism in 24 sedentary, obese [body mass index (kg/m2): 32 ± 1 (x̄ ± SEM)] postmenopausal women aged 58 ± 1 y. Design: Total body fat and fat-free mass were measured by using dual-energy X-ray absorptiometry. Intraabdominal fat (IAF), subcutaneous abdominal fat (SAF), midthigh fat, midthigh muscle, and midthigh low-density lean tissue areas were measured by using computed tomography. Glucose and insulin responses were determined with a 3-h oral-glucose-tolerance test. Results: Body weight decreased 8% (P < 0.001) and maximal aerobic capacity increased 8% (P < 0.001) with the weight loss and walking program. Total body fat decreased by 15% (P < 0.001) whereas fat-free mass did not change. IAF and SAF decreased by 18% and 16%, respectively (P < 0.001). Midthigh fat and midthigh low-density lean tissue decreased by 16% and 18%, respectively (P < 0.001), and midthigh muscle area increased by 7% (P < 0.05). Fasting plasma insulin decreased by 12% and total glucose and insulin areas under the curve decreased by 6% and 24%, respectively (P < 0.05). HDL-cholesterol concentrations increased 8% (P < 0.05) and triacylglycerol concentrations decreased 19% (P < 0.001). Conclusion: Increased physical fitness and weight loss reduce midthigh low-density lean tissue and improve glucose and lipid metabolic risk factors for CVD in obese postmenopausal women.