Objective. To examine the trend of obesity-associated diseases in youths and related economic costs.

Methods. Using a multiyear data file of the National Hospital Discharge Survey, 1979–1999, we analyzed the changes in obesity-associated diseases and economic costs in youths (6–17 years of age) over time. Diabetes, obesity, sleep apnea, and gallbladder disease were examined to explore the trend of the disease burden. Other obesity-associated diseases for which obesity was listed as a secondary diagnosis were also analyzed. Obesity-associated hospital costs were estimated from the discharges with obesity listed as a principal or secondary diagnosis.

Results. From 1979–1981 to 1997–1999, the percentage of discharges with obesity-associated diseases increased. The discharges of diabetes nearly doubled (from 1.43% to 2.36%), obesity and gallbladder diseases tripled (0.36% to 1.07% and 0.18% to 0.59%, respectively), and sleep apnea increased fivefold (0.14% to 0.75%). Ninety-six percent of discharges with a diagnosis of obesity listed obesity as a secondary diagnosis. Asthma and some mental disorders were the most common principal diagnoses when obesity was listed as a secondary diagnosis. Obesity-associated annual hospital costs (based on 2001 constant US dollar value) increased more than threefold; from $35 million (0.43% of total hospital costs) during 1979–1981 to$127 million (1.70% of total hospital costs) during 1997–1999.

Conclusions. Among all hospital discharges, the proportion of discharges with obesity-associated diseases has increased dramatically in the past 20 years. This increase has led to a significant growth in economic costs. These findings may reflect the impact of increasing prevalence and severity of obesity. Diet and physical activity interventions should be developed for weight loss and prevention of weight gain in youths.