The natural history of the development of obesity in a cohort of young U.S. adults between 1981 and 1998.
BACKGROUND
Understanding the natural history of obesity in a population may be a critical step toward developing effective interventions.


OBJECTIVE
To assess the development of body mass and examine the role of race or ethnicity, sex, and birth year in obesity onset in young U.S. adults.


METHODS
Prospective cohort study.


METHODS
The National Longitudinal Survey of Youth 1979, a national sample with oversampling of minority ethnic groups.


METHODS
9179 persons.


METHODS
Body mass index (BMI) calculated from 12 self-reported height and weight samples recorded between 1981 and 1998. Logistic regression identified predictors of obesity at age 35 to 37 years. Cox proportional hazards models compared the incidence of obesity by ethnicity and birth year.


RESULTS
Overall, 26% of men and 28% of women were obese (BMI > or = 30 kg/m2) by age 35 to 37 years. Race or ethnicity and baseline BMI were significant predictors of obesity. Obesity onset was 2.1 (95% CI, 1.6 to 2.7) times faster for black women and 1.5 (CI, 1.1 to 2.0) times faster for Hispanic women than for white women. The pattern for men differed: Overall, obesity developed most rapidly in Hispanic men, but relative rates of obesity onset for white men compared with black men varied according to age. The rate of obesity onset increased 26% to 28% over an 8-year span in birth year.


CONCLUSIONS
Marked ethnic-based differences were found in rates of weight accumulation in young U.S. adults, with later birth cohorts experiencing earlier onset of obesity. To alter the course of obesity in the United States, interventions should target young adults, especially those of minority ethnic groups.
McTigue
Kathleen M
KM
5034 Old Clinic Building, CB#7105, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7105, USA. kathleen_mctigue@unc.edu
Garrett
Joanne M
JM
Popkin
Barry M
BM
D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data; D017677:Age Distribution; D017668:Age of Onset; D015992:Body Mass Index; D005260:Female; D006630:Hispanic or Latino / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D009765:Obesity / Q000453:epidemiology* / Q000208:ethnology; D015995:Prevalence; D016016:Proportional Hazards Models; D011446:Prospective Studies; D017678:Sex Distribution; D014481:United States / Q000453:epidemiology; D044465:White People / Q000706:statistics & numerical data