Childhood Obesity Prevention from Pregnancy and Infancy Onward

First Lady Michelle Obama unveiled her “Let’s Move” campaign against childhood obesity on February 9, 2010. The program’s main antiobesity strategies are empowering parents and consumers by revamping the nutritional labeling of products by the U.S. Department of Agriculture (USDA), improving the nutritional standards of the National School Lunch Program, increasing children’s opportunities for physical activity, and improving access to high-quality foods in all U.S. communities (www.letsmove.gov).

This innovative multifactorial approach has potential for altering the course of the childhood obesity crisis — changing our country’s approach to eating, nutrition, and physical activity by simultaneously targeting individuals, neighborhoods, and larger communities. Current data on obesity in school-age children are sobering. Almost one third of U.S. children over 2 years of age are already overweight or obese, according to the 2007–2008 National Health and Nutrition Examination Survey (see graph), and among low-income children 2 to 5 years of age who are enrolled in federally funded health programs, the proportions range as high as 39% (see map, and the interactive map available with the full text of this article at NEJM.org).

But systematic reviews indicate that, at best, behavioral and nutrition interventions in schools or within the home have limited success in preventing weight gain in children. At as early as 3 years of age, obese children have elevated levels of inflammatory markers that have been linked to heart disease that is manifested later in life. To be a truly comprehensive and successful program, then, the Let’s Move campaign must stimulate prevention efforts targeting the youngest Americans — those under 2 years of age and preschoolers. Indeed, prevention must start as early as possible, since school-age children already have an unacceptably high prevalence of obesity and associated medical conditions.

Factors associated with increased risk for overweight or obesity in infancy and early childhood include excessive maternal weight gain or smoking during gestation, shorter-than-recommended duration of breast-feeding, and suboptimal amounts of sleep during infancy. Such exposures during early development program a person's long-term regulation of energy balance and may have epigenetic effects. These exposures probably influence the development of hypothalamic circuits that regulate body weight, as well as endocrine pancreatic function, changes in the proportion of lean versus fat body mass, and other cycles of metabolic programming.

Interventions designed to reduce excessive weight gain and smoking during pregnancy, to increase the duration of breast-feeding, and to increase sleep duration during infancy could target U.S. children before they became overweight or obese, intervening in the cycle of metabolic programming that can be influenced by these early-life exposures. We believe that these types of interventions are crucial to include in a comprehensive obesity-prevention effort, since they affect a child's lifetime risk of obesity.