The Physical Activity and Energy Expenditure of Obese Middle-aged and Old Men

Objective:The objective of this study was to evaluate the physical activity level, resting metabolism rate, ubstrate utilization during specific physical activity in obese men and normal weigh controls, which would give reference for discussion of the aetiology and intervention of obesity.Methods:14 obese (BMI>30) and 15 normal weight (BMI=23) individuals aged 50⁶0 years old were monitored physical activity by using accelerometer RT3 in 7 consecutive days.After that, resting metabolism rate and energy expenditure rate during specific physical activity were taken by Cortex MetaMax 3B (sitting, standing, and walking with velocity of 3.2km/h, 4.8km/h, and 6.4km/h) .Results:1) The daily total energy expenditure (TEE) , PAEE, moderate activity energy expenditure (MPEE) , and the cumulative time of the physical activity above moderate level were remarkably greater than the control group (P<0.05) .After the adjustment of weight, the daily TEE/kg of the obese was somewhat less than the control group, but the PAEE/kg was remarkably higher than the control group.2) The resting energy expenditure of the obese was higher than the normal weight subjects, and if it was calculated by per weight, RMR was remarkably lower than the latter group (P<0.05) .3) In the activities (sitting, standing, walking) , the relative EE of the obese group during the sitting and standing was somewhat lower than the control group, while the EE of walking was the same between them.4) In the same activities, the respiratory exchange ratio (RER) of the two groups was the same.When it came to the 6.4km/h, the RER of the obese group was remarkably higher than the normal group (P<0.05) .5) Regression statistics was used to analyze the risk factors of obesity.The RMR could be treated as a predictor of obesity.Conclusion:The daily TEE of the obese is not lower than the normal group.The cause of obesity may be associated with energy metabolism.