Light-Intensity Physical Activity and the Association between BMI and Cardiometabolic Risk Factors in Adults with Obesity

The increased prevalence of chronic health conditions associated with obesity is a significant public health concern. It is generally accepted that physical activity elicits significant health benefits, however, many health benefits have been examined within the context of moderate-to-vigorous physical activity. Routine physical activity can improve several metabolic risk factors associated with cardiovascular disease and is associated with a lower risk of mortality. Currently, there is little evidence that has examined the association of light-intensity physical activity(LPA) and weight loss. Additionally, the relationship between LPA and cardiovascular disease risk factors is unclear. Purpose: The purpose of this study was to examine the associations between light-intensity physical activity BMI and cardiometabolic risk factors in adults with obesity. Methods: Three hundred and eighty-three adults with overweight and obesity (age:45.6± 8.0 years; BMI: 32.4± 3.8 kg/m2) were randomized to DIET, DIET+PA150, and DIET+PA250. 375 participants provided data for baseline analyses, 320 participants provided data for 6-month analyses and 301 participants provided data for 12-month analyses for this study. The intervention prescribed a calorie restricted diet (1200-1800 kcal/day) and physical activity (0, 150, 250 min/week). Results: In adjusted analyses, LPA was associated with significant reductions in body weight from baseline to 6 months (p=0.006) and baseline to 12 months (p=0.003), with similar patterns shown for body mass index and percent body fat. LPA was negatively associated with total cholesterol (p=0.007), LDL cholesterol(p=0.011), triglycerides(p=0.007), and insulin(p=0.038) from baseline to 6 months. HDL was positively associated with LPA (p=0.038) from baseline to 12 months. A positive association between LPA and cardiorespiratory fitness expressed as minutes was shown from baseline to 6 months (p=0.032). Conclusion: This study provides evidence that within the context of a behavioral weight loss intervention, LPA is significantly associated with reductions in body weight and body fatness, and with some other cardiometabolic risk factors. These findings suggest that even in the absence of MVPA, LPA may have modest but clinically important influences on some health-related outcomes in adults with overweight or obesity