Objective: We compared health outcomes in obese adults who underwent 12 wk of exercise counseling with or without dietary counseling, followed by 12 wk of observational monitoring.
Methods: Ninety adults (77 women and 13 men; 42.6 +/- 6.0 y; body mass index, 31.5 +/- 2.8 kg/m(2)) were randomly assigned to exercise-only (EX) or diet-plus-exercise (DEX) groups and counseled weekly by exercise physiologists on a 12-wk walking program. DEX subjects were also counseled by dietitians on a hypocaloric diet (-500 kcal/d). From weeks 12 to 24, subjects were monitored but not counseled. At weeks 0, 12, and 24, data collection included body composition (air displacement plethysmography), fitness (maximum oxygen consumption, 3-min step-test, and timed mile), plasma lipids, weight loss efficacy (Weight Efficacy Life-Style Questionnaire), quality of life (Medical Outcomes Study Health Survey-Short Form 36), and mood (Profile of Mood States).
Results: At 12 and 24 wk, weight and body mass index decreased in DEX subjects (both P < 0.05) but not in EX subjects. However, lean body mass increased significantly in EX (24 wk, P < 0.05) but not in DEX subjects. In both groups, fat mass decreased (P < 0.05 for EX subjects at 24 wk; P < 0.05 for DEX subjects at 12 and 24 wk) and waist circumference decreased (P < 0.05 for EX subjects at 12 and 24 wk; P < 0.05 for DEX subjects at 12 and 24 wk). At 12 and 24 wk, DEX subjects showed decreased levels of total plasma cholesterol and triacylglycerols (both P < 0.05) and improvements with regard to the Weight Efficacy Life-Style Questionnaire (P < 0.05), three domains of the Medical Outcomes Study Health Survey-Short Form 36 (all P < 0.05), and three domains of the Profile of Mood States (all P < 0.05) that were not seen in EX subjects.
Conclusions: Exercise counseling for 12 wk in obese adults improves some body composition indices that can be sustained over 12 wk of monitoring. The addition of dietary counseling increases improvements in body composition, lipid profiles, and several psychological parameters.