Maternal diet during pregnancy and offspring obesity

The number of overweight and obese people has increased dramatically in recent years, and the World Health Organization formally recognizes obesity as one of the greatest health challenges of our time. For the first time in history, there are now more overweight than underweight people in the world. The increase in the number of overweight children is particularly worrisome and poses many health risks to the young generation. In Austria, approximately every fifth child is overweight, and every tenths child is obese. For many years, adult lifestyle factors, in particular lower levels of physical activity and unhealthy dietary habits together with a genetic susceptibility have been believed to be the primary causes of obesity. In recent years, however, it is increasingly recognized that the obesity risk could be programmed before birth. For example, it is well known that children of mothers with excess weight gain or gestational diabetes in pregnancy have an increased risk to become obese in later life. In addition, animal studies suggest that the mothers diet during pregnancy has an impact on their offsprings weight development. One underlying mechanism could be epigenetics (modifications to DNA that can turn genes on or off) in which one-carbon nutrients could play an important role. Unfortunately, findings from animal studies are not necessarily generalizable to human populations. In the planned project, I propose to analyze data from almost 5,000 mother-child pairs from two large, well- known U.S. studies, the Nurse Health Study II and the children enrolled in the offspring cohort named Growing Up Today Study. In both studies, mothers and children fill in questionnaires every two to four years, telling what and how much they eat, what medicines they take, what their weight is, what illnesses they have and whether they exercise regularly or take any vitamin supplements, among other things. The overall objective of the proposed project is to examine the associations between maternal diet quality and the intake of one-carbon nutrients (including vitamin B6, vitamin B12, methionine and folate) during pregnancy and weight development in the children until early adulthood. The hypothesis is that children born to mothers with greater adherence to healthful dietary patterns and greater intake of one-carbon nutrients have a lower risk of developing overweight or obesity and are leaner compared to children of mothers with less adherence or lower intake of these nutrients. This research is important because it could potentially provide novel strategies for interventions with the ultimate goal to break the intergenerational vicious cycle of obesity. The project will be carried out at the Medical University of Vienna, Center for Public Health, Department of Epidemiology and includes a research visit to the Channing Division of Network Medicine at Harvard Medical School home of the NHS2 and GUTS2 cohorts.

Obesity is caused by many factors, including early life environments as well as genetics. Studies suggest that the diet of mothers during pregnancy is related to the risk of obesity in their offspring. We studied the association between healthy eating patterns during the time surrounding pregnancy and the weight development of children and found no evidence that the mothers overall dietary pattern was related to the weight of their children. However, mothers who ate more choline, a nutrient mainly found in meat, fish, dairy, and eggs had children with higher birth weight and the children had a slightly higher risk of having overweight and obesity later in life. In addition, people differ in their genetic background and therefore genetic risk to develop overweight and obesity. We have shown that some people have a genetic predisposition to snack and overeat, and they have a harder time staying normal weight.