Dietary prescription adherence and non-structured physical activity following weight loss with and without aerobic exercise.

OBJECTIVES

To compare the effects of weight loss with and without exercise on 1) dietary prescription adherence and 2) non-structured activity in postmenopausal women.

DESIGN

Longitudinal study.

SETTING

Clinical research setting with facility based exercise and nutrition education.

PARTICIPANTS

Overweight and obese women, 45-76 years old.

INTERVENTION

6 months of weight loss alone (WL; N=38) or with aerobic exercise (AEX+WL; N=41).

MEASUREMENTS

Cardiorespiratory fitness (VO2max), resting metabolic rate (RMR), seven day food intake, and physical activity (by Actical accelerometers worn in a subset subgroup: WL: N=10; AEX+WL: N=15) were assessed before and after the interventions.

RESULTS

Both interventions resulted in similar weight loss (9%) and no significant changes in RMR, while only the AEX+WL group improved VO2max (10%). At baseline, the AEX+WL group consumed slightly more protein than the WL group (P<0.01). Macronutrient intake did not change following AEX+WL, but the WL group decreased their fat intake and increased their carbohydrates and protein intakes (Ps<0.05), which resulted in similar macronutrient intakes between groups post-intervention. Weekday total activity counts decreased 22% (P<0.05) following WL. This change tended (P=0.07) to be different than the lack of change in non-structured activity observed following AEX+WL.

CONCLUSION

Although similar dietary adherence was observed, these data suggest that postmenopausal women undergoing weight loss may benefit from the addition of exercise to prevent the decline in non-structured activity observed following weight loss alone.