Although the prevalence of obesity has increased in recent years, individuals who are obese early in life have not been followed over time to determine whether they develop severe obesity in adulthood, thus limiting effective interventions to reduce severe obesity incidence and its potentially life-threatening associated conditions.
A US nationally representative cohort was followed from adolescence through adulthood to determine incidence of severe obesity in adulthood and which groups are at highest risk.
Design, Setting, and Participants
Subjects included 8,834 individuals enrolled in wave II (1996: 12–21 y) of the National Longitudinal Study of Adolescent Health and followed into adulthood [wave III (2001–2002: 18–27 y), and wave IV (2007–2009: 24–33 y)]. Data come from measured height and weight obtained via anthropometry and surveys administered in study participants' homes using standardized procedures.
Main Outcome Measures
New cases of adult-onset severe obesity were calculated by sex, race/ethnicity, and adolescent weight status. Sex-stratified, discrete time hazard models estimated the net effect of adolescent obesity (<20 y, body mass index [BMI]≥95th percentile of the sex-specific BMI-for age growth chart or BMI≥30.0) on risk of severe obesity incidence in adulthood (≥20 y, BMI≥40.0), adjusting for race/ethnicity and age and weighted for national representation.
In 1996, 1.0% (95% Confidence Interval [CI], 0.7%–1.4%; n=79) of adolescents were severely obese and 70.5% (95% CI, 57.2%–83.9%; n=60) remained severely obese in adulthood. By 2009, 7.9% (95% CI, 7.4%–8.5%; n=703) of non-severely obese adolescents became severely obese in adulthood, with highest rates for non-Hispanic black females. Obese adolescents were significantly (Hazard Ratio, 16.0; 95% CI, 12.4, 20.5) more likely to develop severe obesity in young adulthood than normal weight or overweight adolescents.
Obesity in adolescence was significantly associated with increased risk of incident severe obesity in adulthood, with variation across sex and race/ethnicity.