Mechanisms underlying the association between breastfeeding and obesity

Decades of epidemiological research have established that breastfeeding is associated with a modest reduction in risk of later overweight and obesity. However, no systematic effort has been made to delineate the mechanisms that may explain this association. This review summarizes evidence from a variety of disciplines to understand the potential mechanisms underlying this association. One possibility is that this association is spurious and that confounding factors fully or partially explain this association. Additionally, breastfeeding could confer protection by: encouraging the infant\u27s emerging capabilities of self-regulation of intake; reducing problematic feeding behaviors on the part of caregivers that interfere with the infant\u27s self-regulation of intake; and providing bioactive factors that regulate energy intake, energy expenditure, and cellular chemistry. These three protective effects may promote slower growth and lower body fat levels in breastfed infants, which reduce risk of overweight and obesity later in life

Opportunities for the Primary Prevention of Obesity during Infancy

Are chubby babies healthy babies? Whereas most seem well during infancy, evidence is increasing that heavier babies have a poorer long-term health trajectory than their trimmer counterparts. Data have emerged over the past 2 decades that early life growth patterns and behaviors play an important role in the etiology of obesity, yet there has been very little focus on the primary prevention of obesity during infancy by the medical, behavioral health, and public health communities. A recent report from the National Health and Nutrition Examination Survey (NHANES) highlighted the need for very early intervention when it revealed that between 2003 and 2006, a staggering 24.4% of children aged 2 to 5 years already were overweight or obese (body mass index [BMI; calculated as the weight in kilograms divided by height in meters squared] 85th–94th and ≥95th percentiles, respectively) [1]. NHANES data also have described obesity (weight-for-length/height ≥95th percentile) among infants younger than 2 years ( Fig. 1). Between the late 1970s and 2000, the prevalence of obesity among infants 6 to 23 months old increased by more than 60% [2]. Reports from the Centers for Disease Control and Prevention (CDC) Pediatric Nutrition Surveillance System [3] and a Massachusetts Health Maintenance Organization [4] similarly showed significant increases in the prevalence of overweight for infants and toddlers for all age groups since the 1980