Overall, experts agree, breastfeeding is a healthy way to a healthy baby, as the antibodies in a mother’s milk fight off viruses and bacteria.
However, a new study on mice suggests that a mother who isn’t careful about her food intake might end up doing more harm than good to her baby.
A study presented on March 18 at ENDO 2018, the Endocrine Society's 100th annual meeting in Chicago, suggests mothers who overeat while breastfeeding may increase the risk of their kids becoming obese and going through early puberty.
"Formula feeding is well known to increase the risk of obesity in children. Our findings suggest, however, that when breastfeeding mothers do not eat a moderate and healthy diet, there can also be increased risks of various health problems in the offspring, including obesity, diabetes, advanced puberty and reduced fertility," lead researcher Mengjie Wang, MD, MS, a graduate research assistant at the University of Toledo College of Medicine and Life Sciences in Toledo, Ohio, said. "This idea must be tested in humans to know whether it applies to our species."
To determine how being overweight affects the onset of puberty, Wang gave mice a high-fat diet from the date they gave birth to when they weaned their pups.
The biological changes between this group and a group of mice on a regular diet were compared for the same amount of time.
Wang found overfeeding the mothers during the crucial breastfeeding time significantly affected puberty. "These results show that the breast-feeding phase is a critical window that influences when puberty happens," Wang said.
Tests also showed those on a high-fat diet while breastfeeding had decreased litter size and impaired pregnancy rate in both female and male mice. The researchers also found these mice suffered from glucose intolerance and insulin insensitivity – which point to risk of diabetes.
"Our results reinforce the findings of previous studies that childhood obesity causes advanced puberty and metabolic disorders in adulthood," Wang said.
