Associations amongst sedentary and active behaviours, energy expenditure, body fat and appetite dysregulation

Purpose The objective was to investigate whether measures of appetite dysregulation were associated with sedentary time, physical activity, energy expenditure or fat mass. Cross-sectional and prospective studies indicate sedentary behaviour is associated with obesity. Most studies use questionnaire based self-report measures of sedentary time. In contrast, this study employed an innovative device that measured motion, galvanic skin response, skin temperature and heat flux. Methods Thirty demographically diverse participants (8men, 22women; age: 49.1±14.2years; BMI: 26.8±4.9kg/m2) took part in this cross-sectional study. Measures of body composition (Bodpod), health markers, cardiovascular fitness and resting metabolic rate (indirect calorimetry), and appetite dysregulation (Three-Factor Eating Questionnaire and Binge Eating Scale) were taken as well as 6-7days measurement of free-living physical activity (light 1.5-3METs; moderate 3-6METs; and vigorous >6METs) and sedentary behaviour (<1.5METs) with the SenseWear Armband (BodyMedia). Active energy expenditure was calculated by subtracting measured resting metabolic rate from total measured energy expenditure calculated by the Armband. Results A minimum of 6 full days (>22h/day) were analysed for each participant (7days: n=14; 6days: n=16). Average wear-time of the SenseWear Armband was 98±1.3% of total possible wear-time. Sedentary behaviour was positively correlated with multiple indices of adiposity including fat mass (r=.39,p<.05), body fat percentage (r=.38,p<.05) and waist circumference (r=.40,p<.05). Moderate-to-vigorous physical activity (>3 METs) was negatively associated with fat mass (r=-.69,p<.001), body fat percentage (r=-.70,p<.001) and waist circumference (r=-.65,p<.001). Physical activity and sedentary behaviour were not associated with indices of appetite dysregulation. TFEQ Disinhibition and Binge Eating were positively associated with BMI (r=.75,p<.001;r=.57,p=.001), fat mass (r=.70,p<.001;r=.58,p=.001), body fat percentage (r=.63,p<.001;r=.45,p<.05) and waist circumference (r=.69,p<.001;r=.58,p=.001) but not with lean mass (r=.24(ns);r=.13(ns)). Active energy expenditure was negatively associated with sedentary time (r=.-43,p<.05) and positively associated with moderate-to-vigorous physical activity (r=.45, p<.05). Conclusion Sedentary time was associated with low energy expenditure and higher adiposity whereas MVPA was associated with higher energy expenditure and lower adiposity. Higher adiposity (but not sedentary time, physical activity or low energy expenditure) was associated with Disinhibition and Binge Eating (appetite dysregulation).