Effect of an energy-restrictive diet, with or without exercise, on lean tissue mass, resting metabolic rate, cardiovascular risk factors, and bone in overweight postmenopausal women

Abstract

Purpose: To study the effect of exercise added to an energy-restrictive diet in overweight postmenopausal women.

Subjects and methods: In a longitudinal clinical study, 121 healthy, overweight postmenopausal women (age 53.8 +/- 2.5 years, body mass index: 29.7 +/- 3.1 kg/m2) were randomly assigned to 3 groups: controls, a 4,200 kJ/d diet, or a 4,200 kJ/d diet with combined aerobic and anaerobic exercise. Body composition (measured by dual-energy x-ray absorptiometry), fat distribution, resting metabolic rate, blood pressure, serum lipids and lipoproteins, bone mineral densities, and markers of collagen and bone turnover were measured before and after 12 weeks of intervention.

Results: One hundred eighteen women completed the study. The mean loss of body weight (9.5 kg versus 10.3 kg, NS) was similar in the intervention groups, but compared with the diet-only group, the diet-plus-exercise group lost more fat (7.8 kg versus 9.6 kg, p < 0.001) and no lean tissue mass (1.2 kg versus -0.0 kg, p < 0.001). The resting metabolic rate (per kg wt) was increased in the diet-plus-exercise group compared with the control group (11% versus 4%, p < 0.009). The levels of serum triglycerides, total cholesterol, low-density lipoprotein, and very-low-density lipoprotein decreased, and the ratio of high-density lipoprotein to low-density lipoprotein increased by 20% to 30% in both intervention groups compared with the control group (p < 0.001). The systolic blood pressure dropped, and the waist-to-hip circumference ratio and abdominal-to-total body fat decreased in both intervention groups compared with the control group (10%, p < 0.003, and 3.5%, p < 0.0001). There were no consistent, major differences between the groups in terms of changes in total body, spinal, or forearm bone mineral densities, or in markers of collagen and bone turnover.

Conclusion: Overweight postmenopausal women benefit from addition of combined aerobic and anaerobic exercise to an energy-restrictive diet. The diet itself has a positive effect on cardiovascular risk factors.