Childhood obesity seems destined to be America’s next health crisis. The consequences of childhood obesity reach far beyond psychological misperceptions of self-image and self-worth to individual organ systems, life expectancy, cognitive and academic development, vocational success and societal impact.
At present, America is witnessing the most disturbing growth of childhood obesity ever recorded in history. The Centers for Disease Control reports 32 percent of all children and adolescents in the US are overweight or obese. This number has tripled in one generation, meaning the current trajectory indicates 100 percent of our children could be overweight and obese in the next generation if we don’t act fast. Obese children usually become obese adults, making the significance of this issue clearer: preventing childhood obesity is foundational for curtailing adult obesity.
One of the simplest and most cost effective tools for initiating a reversal of this trend begins at birth. The link between breastfeeding and obesity is not new, but is seeing a reawakening in scientific literature as a result of recent trends and medical concerns. Breastfeeding is associated with modest to significant reductions in risks of being overweight or obese, with the most significant risk reductions seen when breastfeeding occurs for at least 6 months. Researchers investigating the protective effect of breastfeeding against obesity studied 2,209 children fed exclusively breast milk or formula for greater than 6 months. When evaluated at 2 years, children fed breast milk exclusively were half as likely to be overweight as formula fed children. Another study of 16,224 European children, ages 2 – 9 years, also indicated that breastfeeding for at least 6 months was protective against being overweight or obese in childhood. These large-scale studies are good evidence that initial feeding choices can impact obesity risks in children almost as soon as weaning occurs.
Many researchers have suggested that the slower growth acceleration seen in breastfed infants is indicative of differing nutrient compositions between breast milk and formula. Formula has a higher protein composition and a slightly higher caloric density compared to the fat-dominating composition of breast milk. Higher protein may induce a higher insulin response and higher IGF-1 values, promoting greater fat storage and accelerated growth during the childhood years. In rodent models, high protein during the postnatal period resulted in a 10-40 percent increase in adult body weight. Initial follow ups from a randomized, double-blind intervention trial investigating growth outcomes of higher or lower protein intakes during the first year of life indicated higher protein intakes lead to a significantly higher body weight and BMI at the age of 2 years.
Other explanations focus on the unique hormone composition of human breast milk. Leptin, ghrelin, adiponectin, resistin, IGF-1 and other hormones are found in breast milk and exert protective benefits on body composition and metabolism in infants. Leptin reduces appetite and increases energy expenditure while ghrelin stimulates appetite. These hormones symbiotically program healthy appetite habits and correctly program human metabolism. Adiponectin is released in higher quantities during initial feeding and is directly associated with adiposity and insulin sensitivity in humans. Obesity and type 2 diabetes have been linked to low serum levels of adiponectin. Resistin is also found in higher quantities during initial feeding and regulates essential, weight-controlling hormones including many sex, adrenal and thyroid hormones. IGF-1 facilitates the behavior of growth hormones and directly impacts the growth rate of infants, children and adults. Various other hormones, native to breast milk, positively program the infant’s eating behaviors and metabolism to promote an ideal and healthy weight throughout life.
It has been proposed that behavioral patterns learned in breastfed infants also protect from obesity. Researchers have suggested that breastfed infants develop better appetite control later in life as a result of learning self-regulation during breastfeeding. A caregiver often governs the feeding patterns of bottle fed infants. Studies show that bottle fed infants may have a 20-30 percent higher feeding volume at each meal, but fewer meals, indicating a longer duration between feedings. Additionally, bottle fed infants tend to show a more vigorous suckling behavior, which has been associated with adiposity in toddlers. These behavioral patterns are instrumental in programming infants to adopt healthy or unhealthy attitudes about eating, which could influence obesity risks.
Most likely, the convergence of several characteristics of breast feeding, including milk composition and behavioral patterns, is responsible for the protective effect against obesity. Regardless, in the wake of escalating obesity rates, breastfeeding seems to be a strong foundational starting point for taking control of our weight and health.
Source: Breastfeeding and Obesity