Introduction: The AHA emphasizes healthy lifestyle habits in 4 domains for pediatric cardiovascular health: nutrition, body size, physical activity, and smoking. We tested the hypothesis that in recent years among US youth, nutrition and smoking improved, while body size and physical activity did not.
Methods: We analyzed cross-sectional data in 15,712 youths aged 6-19 years from 6 NHANES surveys: 2003-04, 2005-06, 2007-08, 2009-10, 2011-12, and 2013-14. We applied survey weights to generate US population-level estimates and used multivariate linear regression to test for time-dependent linear trends in lifestyle habits, separately by sex and age group (6-11 vs. 12-19 years).
Results: See Table. Favorable linear trends were seen across age and sex groups in many nutrient intakes, particularly total energy, solid fats, and added sugars; fiber intake also improved among 6-11 year-old youths. However, prevalence of ideal intakes as defined by clinical guidelines remained low. Favorable trends were also seen in smoking and secondhand smoke exposure. On the other hand, body mass index and waist to height ratio showed no time-dependent trends, except for a small increasing linear trend in the prevalence of obesity for 12-19 year-old youths. Similarly, for physical activity and screen time, the only significant linear trend was decreasing mean physical activity among 12-19 year-old females.
Conclusions: US youth have generally improved nutrition and avoidance of smoking in recent years, although these habits remain suboptimal in the population. Body size and physical activity are not improving, and may be worsening in adolescents.