Diet quality and physical activity in relation to childhood obesity

Objective: Healthy lifestyles such as being physically active and eating a healthy diet help reduce the childhood obesity risk. However, population-level studies on the relationship between lifestyles and childhood obesity typically focus on either physical activity or diet but seldom both. This study examined physical activity and diet quality in relation to obesity in a nationally representative sample of U.S. children and adolescents.

Methods: The study sample of 2818 children 6–17 years old came from the National Health and Nutrition Examination Survey 2003–2006 waves. A healthy eating index (HEI)-2010 was constructed based on two nonconsecutive 24-h dietary recalls. Participants at or above the 60th percentile of the HEI-2010 score were classified as consuming a healthy diet. Participants engaging in at least 60 min of moderate-vigorous physical activity daily measured by accelerometer were classified as being physically active. Adjusted average marginal effect of diet quality and physical activity on obesity was calculated based on estimates from logistic regressions.

Results: Compared with those consuming a healthy diet who are physically active, the estimated probabilities for overweight and obesity were 19.03 (95% confidence interval: 11.31, 26.74) and 15.84 (10.48, 21.21) percentage points higher among children consuming an unhealthy diet and who are physically inactive, 16.53 (7.58, 25.48) and 13.48 (5.68, 21.29) percentage points higher among children consuming a healthy diet but who are physically inactive and 3.22 (−3.43, 9.88) and 3.10 (−3.08, 9.29) percentage points higher among children consuming an unhealthy diet but physically active, respectively.

Conclusion: Healthy habit formation at an early age is essential in obesity prevention.