PREDICTING OBESITY IN YOUNG ADULTHOOD FROM CHILDHOOD AND PARENTAL OBESITY

Background Childhood obesity increases the risk of obesity in adulthoo d, but how parental obesity affects the chances of a child's becoming an obese adult is unknown. We investigated the risk of obesity in youn g adulthood associated with both obesity in childhood and obesity in o ne or both parents. Methods Height and weight measurements were abstra cted from the records of 854 subjects born at a health maintenance org anization in Washington State between 1965 and 1971. Their parents' me dical records were also reviewed. Childhood obesity was defined as a b ody-mass index at or above the 85th percentile for age and sex, and ob esity in adulthood as a mean body-mass index at or above 27.8 for men and 27.3 for women. Results In young adulthood (defined as 21 to 29 ye ars of age), 135 subjects (16 percent) were obese. Among those who wer e obese during childhood, the chance of obesity in adulthood ranged fr om 8 percent for 1- or 2-year-olds without obese parents to 79 percent for 10-to-14-year-olds with at least one obese parent. After adjustme nt for parental obesity, the odds ratios for obesity in adulthood asso ciated with childhood obesity ranged from 1.3 (95 percent confidence i nterval, 0.6 to 3.0) for obesity at 1 or 2 years of age to 17.5 (7.7 t o 39.5) for obesity at 15 to 17 years of age. After adjustment for the child's obesity status, the odds ratios for obesity in adulthood asso ciated with having one obese parent ranged from 2.2 (95 percent confid ence interval, 1.1 to 4.3) at 15 to 17 years of age to 3.2 (1.8 to 5.7 ) at 1 or 2 years of age. Conclusions Obese children under three years of age without obese parents are at low risk for obesity in adulthood , but among older children, obesity is an increasingly important predi ctor of adult obesity, regardless of whether the parents are obese. Pa rental obesity more than doubles the risk of adult obesity among both obese and nonobese children under 10 years of age. (C) 1997, Massachus etts Medical Society.