Introduction
Overweight is an independent predictor of cardiovascular disease (CVD) – the leading cause of death and disability in Western societies. Very little is known about the changes in overweight postmenopausal women since all studies previously have been performed in men and pre-menopausal women. Postmenopausal women are at increased risk of CVD; estrogen deficiency, an atherogenic lipid and lipoprotein profile, and fat distribution all play a role. Osteoporosis is another major cause of morbidity and mortality in this group. The consequences of weight reduction from dieting, with or without exercise, on bone in the osteoporosis are unknown. Thus, the aim was to study the effects of an energy-restrictive diet, with or without exercise, on body composition, major cardiovascular risk factors, and bone in overweight postmenopausal women.
Methods
In a longitudinal clinical study, 121 healthy, overweight postmenopausal women (age 53.8 ± 2.5 years, BMI 29.7 ± 3.1 kg/m2) were randomly assigned to 3 groups: control, a 4,200 kJ/d diet, or a 4,200 kJ/d diet with combined aerobic and anaerobic exercise. The diet consisted of an obligatory basis of the formula diet NUPO of 1.6 MJ daily (VLCD) combined with an additional energy com-consumption of up to 2.6 MJ from food freely chosen, according to a “counter diet system”. 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≤.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
We conclude that, in overweight postmenopausal women, the addition of combined aerobic and anaerobic exercise to a high protein, energy-restricted diet preserves lean tissue mass, promotes physical fitness, and increases the resting metabolic rate and loss of fat. The diet, with or without exercise, led to profound improvements in serum lipids and lipoproteins, blood pressure, and fat distribution. The weight loss induced by the diet, with or without exercise, does not seem to have any major detrimental effect on bone.
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