# News

December 4, 2017

### More than half of children in the US today will be obese adults

More than half of US children between 2 and 19 years old as of 2016 will be obese by the time they hit 35, a study published in the New England Journal of Medicine speculates. The study’s authors used data from Add Health and four other longitudinal studies to create a simulation of respondents’ height and weight over the course of their lives. They also modified the simulation so that it accounts for trends shown in the data over time. Put all that together and you can predict—to a degree—how children born in the past few years will fare as they continue to grow.

Of the categories of BMI classification (underweight or normal weight, overweight, moderate obesity, and severe obesity), children who are currently underweight or normal weight have the best likelihood of not becoming obese by 35, a probability that increases with age: 2-year-olds who are underweight or normal weight have a 43.5% probability of becoming obese by 35, while under- or normal weight 19-year-olds have a 69.7% probability of the same. Basically, the longer a child remains at a BMI classified as underweight or normal weight, the lower the probability they will become obese by the time they turn 35.

What’s more, the opposite is true of children whose BMIs are classified as overweight, moderate obesity, or severe obesity: The likelihood that a 2-year-old in any of these categories will be obese at 35 is lower than that of a 19-year-old. Essentially, the longer a child remains at a BMI classified as overweight, moderate obesity, or severe obesity, the more likely they will still be obese at 35.

Of course, this is not a free pass for children who are currently under- or normal weight: The researchers point out that adult-onset obesity does account for about half of adults who are currently obese. Thus, they recommend widespread obesity interventions, as opposed to interventions targeted only at children who are currently obese.

Authors:

• Zachary J. Ward, M.P.H., Center for Health Decision Science, Harvard T.H. Chan School
• of Public Health
• Michael W. Long, Sc.D., Department of Prevention and Community Health, Milken Institute School of Public Health,  George  Washington  University
• Stephen C. Resch, Ph.D., Center for Health Decision Science, Harvard T.H. Chan School of Public Health
• Catherine M. Giles, M.P.H., Department of Social and Behavioral Sciences, Harvard T.H. Chan School of Public Health
• Angie L. Cradock, Sc.D., Department of Social and Behavioral Sciences, Harvard T.H. Chan School of Public Health
• Steven L. Gortmaker, Ph.D., Department of Social and Behavioral Sciences, Harvard T.H. Chan School of Public Health

Ward, Z. J., Long, M. W., Resch, S. C., Giles, C. M., Cradock, A. L., & Gortmaker, S. L. (2017). Simulation of growth trajectories of childhood obesity into adulthood. The New England Journal of Medicine, 377(22), 2145–2153.