New research from the Baylor College of Medicine in Houston, Texas suggests that women who are overweight or obese before and during their pregnancy will ‘pass on’ their obesity to their unborn child. A pregnant woman who is obese will be in possession of chemicals in her womb that affect the function of the unborn child’s genes. These genes will cause the baby to be heavier than normal and will begin a cycle where each generation will become progressively heavier.
Dr Robert Waterland, the American scientist who led the study, said: "There is an obesity epidemic in the U.S. and it's increasingly recognized as a worldwide phenomenon. Why is everyone getting heavier and heavier? One hypothesis is that maternal obesity before and during pregnancy affects the establishment of body weight regulatory mechanisms in her baby. Maternal obesity could promote obesity in the next generation.”
The results were obtained by conducting trials on mice that were specially bred to have a genetic disposition to overeat. These mice were then separated and put into two groups. One of the groups was given a standard diet while the other was given a diet that was supplemented with various nutrients. These nutrients, which included folic acid, vitamin B12, betaine and choline, resulted in a process called "DNA methylation" - a chemical reaction that silences genes which it is thought lead to obesity.
It was found that the mice that were fed the ‘normal’ diet gained weight with each generation while the mice that were placed on the nutrient rich diet stayed approximately the same size. The researchers put this result down to the fact that DNA methylation plays an important role in the development of the hypothalamus, the part of the brain that is responsible for controlling appetite.
Karen Lillycrop, a doctor from Southampton University said that the findings were ‘interesting’ but said that they were not conclusive in proving that the epigenetic effect was responsible for the effects seen the trial mice. She said that although the combination of nutrients and folic acid had prevented the unborn mice from gaining weight there would be risks if humans were to be given similar amounts of supplements.
In a week where doctors stressed that potential mothers and fathers significantly increase their chances of conception by being a healthy weight, it does seem that there are many gains to me made by losing weight.