Pregnancy diet linked to childhood obesity

An international study has found an association between lower consumption of carbohydrates during early pregnancy and the activity of a gene thought to be linked to increased fat levels in children.

Researchers led by a team from the University of Southampton said the findings indicated a mother's diet during pregnancy may influence the risk of obesity in her child in later life. They found that epigenetic changes in the DNA of children at birth allowed researchers to predict their body weight later on in childhood.

Women were asked to fill in a food questionnaire during pregnancy. Their children's fat levels were measured at either age six or nine. The findings were then compared with DNA extracted from the children's umbilical cord blood.

The study found associations between eating low levels of carbohydrates during the early stages of pregnancy and epigenetic changes in the child's DNA, which are in turn associated with a heavier weight. Studies in animals have already shown that diet during pregnancy can be linked to epigenetic changes in DNA. However, this is the first time such a link has been seen in humans.

Keith Godfrey, Professor of Epidemiology and Human Development at the University of Southampton, said: 'We have shown for the first time that susceptibility to obesity cannot simply be attributed to the combination of our genes and our lifestyle, but can be triggered by influences on a baby's development in the womb, including what the mother ate'.

The epigenetic changes occurred in the RXRA gene. This is the gene responsible for making a receptor for retinoic acid, which is involved in the way cells process fat.

Measuring the changes in this gene allowed researchers to predict the weight of the child later on in life. The study suggests these epigenetic changes on the RXRA gene have a greater effect on the weight of a child than their birth weight, and are not dependent on the weight of the mother.

Professor Mark Hanson, of the British Heart Foundation, said: 'It strengthens the case for all women of reproductive age having greater access to nutritional, education and lifestyle support to improve the health of the next generation, and to reduce the risk of the conditions such as diabetes and heart disease, which often follow obesity'.

Further research is required to determine the significance of the association between the mother's diet during pregnancy and the epigenetic changes, and also the extent of the correlation of these epigenetic changes with a child's weight. The research was published in the journal Diabetes.