Maternal obesity and child weight gain
Childhood obesity is a serious health problem in the United States. About 15 percent of children between ages 6 and 11 are heavier than 95 percent of their peers. Recent research published in the New England Journal of Medicine found the incidence of obesity in children between the ages of 5 and 14 years was four times as high among children who had been overweight at the age of 5 years as among children who had a normal weight at that age.
“Obesity is an epidemic that is increasing the incidence of some cancers, and it starts in childhood,” says Bernard Fuemmeler, Ph.D., M.P.H., professor and associate director of cancer prevention and control in Virginia Commonwealth University’s Department of Health Behavior and Policy. More than two-thirds of adults are considered overweight or obese, as are one-third of children and adolescents ages 6 to 19. Although science is advancing in understanding factors contributing to the obesity epidemic, an area of increasing focus in the field has been on how early periods in the life cycle shape a child’s risk for obesity later in life.
An expert in identifying biological and behavioral contributors to health risk behaviors, Fuemmeler is conducting a study, “Maternal Obesity, Child Executive Functions and Child Weight Gain,” to better understand why children are prone to gain weight early in life with the goal of identifying factors that contribute to this pattern. “If we can identify them,” he says, “we can intervene before children become obese.”
The study looks at whether a link exists between a mother’s pre-pregnancy obesity, her child’s impulsiveness and how her child approaches food and eating. Study participants are mothers who were recruited between 2005 and 2011 from prenatal clinics at Duke University while in their first trimester of pregnancy. The 2,000 women are racially representative of women in the Southeast (38 percent black, 44 percent white, 13 percent Hispanic, 5 percent other). Initial data collected from the women’s first trimesters through their offspring’s infancy included pre-pregnancy weight at the first prenatal visit; gestational weight gain; pregnancy and birth complications; and survey responses regarding nutrition, stress and lifestyle behaviors.
From this existing cohort Fuemmeler is recruiting mothers and their children to conduct detailed assessments of neurodevelopment, appetite regulation, diet, physical activity levels and growth among 400 children at age 4-6 and again, two years later, at age 7-9. “We’re trying to track these children over time to see how lifestyle factors in pregnancy and shortly after birth might influence their health and development,” he says.
Blood specimens collected from the children’s mothers during their first trimesters and from cord blood at birth are being used to assay immune markers and genes important to brain development and growth.
The study’s primary hypothesis is that a mother’s pre-pregnancy obesity and excessive weight gain can disrupt neurodevelopment in such a way as to affect a child’s self-regulation, Fuemmeler says. Poor self-regulation can lead to eating impulsively and when not hungry, which can lead to obesity.
The study is funded through 2020 by the Eunice Kennedy Shriver National Institute of Child Health and Human Development, a component of the National Institutes of Health. “We’d like to follow these kids into adolescence if we can,” Fuemmeler says.
In piecing together risk factors for childhood obesity, Fuemmeler hopes the study will help disentangle the associations between maternal pre-pregnancy obesity, childhood appetite regulation and child weight gain. By understanding how developmental factors shape individual differences that predict childhood obesity, “Maybe we can create tailored prevention programs that shift children’s weight trajectory toward more healthy outcomes,” he says.
Pregnancy and the early period after a child is born are times when many women are receptive to making lifestyle changes, Fuemmeler adds. “Maintaining a healthy weight during these times could not only improve the mother’s health, but may contribute to her child’s health in important ways and curtail the obesity epidemic.”