Background and aim: Sedentary lifestyle contributes to increased body weight in western societies. We evaluated physical activity (PA) and its association with some clinical and biochemical parameters in overweight and obese outpatients.
Methods and results: Two hundred and seventy-eight overweight obese outpatients, aged 18-65 years, were recruited in this cross-sectional study. Patients were interviewed about their usual PA, using a standardized questionnaire. A total metabolic index (TMI) was derived estimating weekly energy expenditure. In Class III obese patients, fasting serum HDL-cholesterol (HDL-Chol) and resting heart rate (HR) were also measured. BMI was inversely related to TMI in the whole group (r = -0.123, p = 0.041). Dividing the patients into groups 1 and 2 according to median BMI (30.3 kg/m(2)), group 1 had a significantly higher TMI than group 2 (p = 0.003), mainly due to the difference in weekly walking time (p < 0.001). Among Class III obese patients, despite similar BMI, the group with longer walking time had both significantly higher HDL-cholesterol (p = 0.046) and lower HR (p < 0.001).
Conclusion: In overweight and obese individuals BMI is inversely related to PA energy expenditure. This relationship can be, at least in part, ascribed to the reduction of weekly walking time with increasing BMI. In Class III obese patients, even a low level of PA can positively affect both HDL-Chol and resting HR. It appears useful to focus on obese patients in also in general practice in order to recognize sedentary life styles and encourage PA through individualized programs.