Extending the History of Child Obesity in the United States: The Fels Longitudinal Study, Birth Years 1930 to 1993

OBJECTIVE: Little is known about the prevalence of child obesity in the U.S. before the first national survey in 1963. There is disagreement about whether the obesity epidemic is entirely a recent phenomenon or a continuation of longstanding trends. METHODS: We analyze the BMIs of 1,116 children who participated in the Fels Longitudinal Study near Dayton, Ohio. Children were born between 1930 and 1993 and measured between 3 and 18 years of age. RESULTS: Between the birth cohorts of 1930 and 1993, the prevalence of obesity rose from 0% to 14% among boys and from 2% to 12% among girls. The prevalence of overweight rose from 10% to 28% among boys and from 9% to 21% among girls. The mean BMI Z-score rose from +0.25 to +0.72 among boys and from −0.11 to +0.26 among girls. Among boys, all these increases began after birth year 1970. Among girls, obesity began to rise after birth year 1970, but overweight and BMI Z-scores were already rising as early as the 1930s and 1940s. CONCLUSIONS: Most of the results suggest that the child obesity epidemic was recent and sudden. The recency of the epidemic offers some hope that it may be reversed.