Children’s Health Capital Investment: Effects of U.S. Infant Breastfeeding on Teenage Obesity

Obesity, as a health and social problem with rising prevalence and soaring economic cost, is increasingly drawing scholarly and public policy attention. While many studies have suggested that infant breastfeeding protects against childhood obesity, empirical evidence on this causal relationship is fragile. Using the health capital development theory, this study exploited multiple data sources from the U.S. and a three-way error components model (ECM) with a jackknife resampling plan to estimate the effect of in-hospital breastfeeding initiation and breastfeeding for durations of 3, 6, and 12 months on the prevalence of obesity during teenage years. The main finding was that a 1% rise in the in-hospital breastfeeding initiation rate reduces the teenage obesity prevalence rate by 1.7% (9.6% of a standard deviation). The magnitude of this effect declines as the infant breastfeeding duration lengthens—e.g., the 12-month infant breastfeeding duration rate is associated with a 0.53% (3.7% of a standard deviation) reduction in obesity prevalence in the teenage years (9th to 12th grades). The study findings agree with both the behavioral and physiological theories on the long-term effects of breastfeeding, and have timely implications for public policies promoting infant breastfeeding to reduce the economic burden of teenage and later adult-stage obesity prevalence rates.