Background: There are few long-term follow-up data on the relation between body mass index (BMI) in adolescence and in adulthood, and between adolescent BMI and adult mortality. The present study explores these relations.
Methods: In Norwegian health surveys during 1963–1999, height and weight were measured for 128,121 persons in a standardized way both in adolescence (age 14–19 years) and 10 or more years later. Persons were followed for an average of 9.7 years after the adult measurement. Cox proportional hazard regression models were used to study the association between adolescent and adult BMI and mortality.
Results: The odds ratio of obesity (BMI ≥30) in adulthood increased steadily with BMI in adolescence, from 0.2 for low BMI up to 16 for very high BMI. Very high adolescent BMI was associated with 30–40% higher adult mortality compared with medium BMI. Adjusting for adult BMI explained most of the association of adolescent obesity and mortality, especially among men. Adjustment for smoking did not change the results.
Conclusions: Obesity in adolescence tends to persist into adulthood. Adolescent obesity is also connected to excess mortality, but this excess seems to be explained mostly by obesity in adulthood. High BMI in adolescence seems to be predictive of both adult obesity and mortality.
From the *Division of Epidemiology, Norwegian Institute of Public Health, Oslo, Norway; and the †Department of Pathology, The Norwegian Radium Hospital, Oslo, Norway.
Submitted 29 January 2003; final version accepted 12 September 2003.
Correspondence to: Anders Engeland, Division of Epidemiology, Norwegian Institute of Public Health, P.O. Box 4404 Nydalen, N-0403 Oslo, Norway. E-mail: email@example.com.