Dieting During Pregnancy Can Make Baby Obese

New research shows that women who count calories during pregnancy could be sentencing their unborn offspring to a lifetime of obesity. Scientists have discovered that a mother’s nutrition during pregnancy can strongly influence her child’s risk of obesity many years later.

An international study, led by University of Southampton researchers and including teams from New Zealand and Singapore, has shown for the first time that during pregnancy, a mother’s diet can alter the function of her child’s DNA. The study will be published in the printed version of the journal Diabetes on 26 April 2011.

It is thought that a lack of food in the womb alters the programming of the baby's fat cells leading to weight problems later in life. Researchers have established a link between a mother's diet while pregnant and the probability that her child will be obese. The process, called epigenetic change, can lead to her child tending to lay down more fat. Importantly, the study shows that this effect acts independently of how fat or thin the mother is and of child’s weight at birth. This chemical process increases the likelihood of obesity at the ages of six and nine years. Epigenetic changes alter the function of DNA without changing the actual DNA sequence inherited from the mother and father. Such changes can also influence how a person responds to lifestyle factors such as diet or exercise for many years to come.

Professor Sir Peter Gluckman reports that an unbalanced diet can increase the risk of childhood obesity. He added that it is not just women who should be mindful, as it is likely obese fathers change the DNA in the sperm, ultimately influencing how the baby develops its control of blood sugar and fat deposition after that baby grows up.

This study 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.