Breastfeeding may protect high-birthweight infants from childhood obesity

"High birthweight is associated with overweight or obesity during early childhood. Among high-birthweight infants, exclusive breastfeeding is a significant protective factor against overweight and obesity," said lead study author Hae Soon Kim, M.D., of Ewha Womans University College of Medicine in Seoul.

High-birthweight infants were highly likely to meet the criteria for obesity or overweight through 6 years of age compared with normal birthweight infants. But the risk of becoming overweight or obese dropped significantly among the high-birthweight infants who were breastfed for first six months of life," Kim added.

In a retrospective cohort study, Kim and co-authors, all of Ewha Womans University College of Medicine, investigated the weight-growth trajectory and the protective effect of breastfeeding for obesity in children. They analyzed data between January 1, 2008 and December 31, 2016 from the National Health Information Database (NHID) of Korea.

The researchers followed 38,039 participants who were completely eligible for all health checkups from birth through 6 years of age. At each check-up period, the authors examined the association between birthweight status and growth development.

Infants were assigned to one of three groups by birthweight: the low-birthweight group, less than or equal to 2,500 grams; the normal-birthweight group, over 2,500 grams and under 4,000 grams; and the high-birthweight group, 4,000 grams or more.

During the follow-up period, about 10 percent of the low-birthweight infants and 15 percent of the normal-birthweight developed obesity or overweight. By contrast, more than 25 percent of the high-birthweight infants met the criteria for obesity or overweight.

The high-birthweight infants were highly likely to be overweight or have obesity compared with normal birthweight infants through 6 years of age, and the low-birthweight infants were highly likely to be underweight through 6 years of age.

But the risk of overweight or obesity decreased significantly if high-birthweight infants were exclusively breastfed for the first six months of life.

"The increase in the prevalence of childhood overweight and obesity, which began in the 1970s, has grown into a global epidemic. Obesity persists from childhood to adolescence and into adulthood and is a leading cause of health problems," the authors cautioned in their abstract.

The Ministry of Health & Welfare of the Republic of Korea funded the study.