Infections in Infancy and Association with Long-Term Weight Gain and Obesity in Children, Southern California, USA.

Chronic obesity is a growing public health threat in the United States; >40% of adults are affected. We retrospectively assessed the frequency of medically attended infection in infants born during 2008-2012 relative to absolute weight and body mass index outcomes at age 4-6 years of age and 10-15 years of age. Multivariable regression revealed those with early clinical infection had higher rates of obesity at 4-6 years and 10-15 years than those without, proportional to the number of infections diagnosed and corresponding to significant weight increases. Compared with infants whose infections were not treated with antimicrobial drugs, treatment was less predictive of weight outcomes. Most infections were viral. Our investigation found a correlation between infections diagnosed in infancy and later weight outcomes, but we could not determine the cause.