Is Childhood Obesity Determined During Pregnancy?

Numerous recent studies have shown that a child’s likelihood of developing obesity may be determined while he or she is still a fetus.

Rockefeller University scientists have found that eating a high-fat diet during pregnancy may cause changes in the fetus’s brain, in turn causing the child to overeat and develop obesity early in life.

Senior author Sarah F. Leibovitz explained that the study, published in the November 12 issue of The Journal of Neuroscience, showed that “short-term exposure to a high-fat diet in utero produces permanent neurons in the fetal brain that later increase the appetite for fat…This work provides the first evidence for a fetal program that links high levels of fats circulating in the mother’s blood during pregnancy to the overeating and increased weight gain of offspring after weaning.”

In a study published in Endocrinology, researchers from the University of New South Wales and France’s National Institute of Health and Medical Research found that overweight pregnant rats were more likely to give birth to babies with more body fat, putting them at increased risk for developing diabetes and obesity later in life. A University of New South Wales news release reported that “obese mother rats fed more milk had pups almost twice as heavy as those born to lean mothers with regular milk consumption at weaning age.”

Margaret Morris, professor of pharmacology, at the University of New South Wales, noted that “as brain control of appetite is likely set early in life, nutrient availability in the fetal or early post-natal period may contribute to adult obesity.”

In another study, conducted at the University of Buffalo, scientists found that obese mother rats “programmed” their babies while in utero to develop adulthood obesity. A University of Buffalo news release reported that these results “have shown for the first time that the metabolic programming occurs in the fetal hypothalamus.” The researchers found that “levels of the hormones insulin and leptin also were elevated in fetuses of these obese mother rats, abnormalities that have been correlated with increased appetite and insulin resistance (a prelude to diabetes), as well as obesity and hypertension.”

Though these experiments were performed in rats, they provide a clear indication of the importance of healthy weight and diet for pregnant women.

Mulchand Patel, PhD, senior author of the University of Buffalo study, observed that “While these studies were done with rats, there is good reason to think the mechanism would be similar in humans…The fact that more than one-third of women of child-bearing age in the United States are expected to be overweight or obese during pregnancy, based on a 2003 study, does not portend well for good health of their offspring.”