Unhealthy weight control behaviors and health risk behaviors in American youth: a repeated cross-sectional study.

Background: Unhealthy weight control behaviors (UWCBs) involve weight control strategies to reduce or maintain weight, such as fasting, taking diet pills, and vomiting or taking laxatives. UWCBs in teenagers can escalate into severe health issues such as eating disorders. Understanding the trends of UWCBs and their association with risk behaviors in teenagers is crucial, as early intervention and prevention strategies are pivotal.

Methods: This study utilized eight waves of the youth risk behavior surveillance system (YRBSS) data from 1999 to 2013. Our primary outcome was UWCBs engagement. We used multinomial logistic models to analyze the association between UWCBs and risk behaviors among adolescents including driving after alcohol consumption, suicide attempts, smoking, alcohol use, and sexual intercourse.

Results: Among 109,023 participants, UWCBs prevalence was 16.64%. Body Mass Index (BMI) was significantly associated with UWCBs risk. In addition, we found the intention of weight management confounded the relationship between BMI and UWCBs. The unadjusted logistic regression indicated a monotone-increasing association between BMI and the risk of UWCBs. In contrast, the adjusted logistic regression indicated a U-shaped curve with the lowest (BMI < 17 kg/m²) and highest (BMI > 30 kg/m²) BMI groups having significantly higher odds of engaging in UWCBs compared to the reference BMI group (18.5 ≤ BMI ≤ 24.9 kg/m²).

Conclusions: The intention of weight management confounded the relationship between Body Mass Index (BMI) and the risk of UWCBs. These findings suggest that healthcare interventions for weight management behaviors should be tailored to adolescents with BMI ≥ 25 and BMI < 18.5.