Indicated prevention of adult obesity: how much weight change is necessary for normalization of weight status in children?

OBJECTIVE To investigate the notion of indicated prevention-helping overweight or obese youth attain non-overweight status to prevent adult obesity-by examining weight-for-height changes needed to normalize weight status in youth who are growing. DESIGN We determined the amount of weight-for-height change necessary for overweight or obese youth to achieve non-overweight status using linear mixed modeling of longitudinal growth patterns and using Centers for Disease Control and Prevention weight thresholds corresponding to the age- and sex-adjusted body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) below the 85th percentile. Mean weight changes among children who achieved nonoverweight status at 1 and 2 years after treatment were calculated. SETTING Weight control programs at 3 research institutions. PARTICIPANTS A total of 669 overweight or obese children aged 8 to 13 years. INTERVENTION Family-based behavioral weight control treatment. MAIN OUTCOME MEASURE Weight. RESULTS Relatively small weight changes (range, -7.55 to +3.90 kg) were necessary for children to achieve nonoverweight status after 1 year; this was most pronounced among younger children (range, -2.90 to +3.36 kg for children aged 8-10 years) and children closer to the 85th BMI percentile (range, +2.44 to +3.90 kg for children at the 90th BMI percentile). Observed weight changes of children who achieved nonoverweight status following treatment were similar to estimates based on Centers for Disease Control and Prevention normative data. CONCLUSIONS Attaining nonoverweight status in childhood is possible with modest weight loss or, in some circumstances, by slowing weight gain, and may help prevent adult obesity. Future research should investigate how much intervention is needed to shift the growth trajectory to nonoverweight status and how much weight-for-height change is needed to improve other health outcomes in adulthood.