A new study published today in eLife has shown that the traditional idea of pregnant women needing to ‘eat for two’ may not be necessary because the body is in fact able to absorb more energy from the same amount of food.
Carried out by the Medical Research Council based at Imperial College London, the study used fruit flies, because of their similar metabolic responses to humans, to demonstrate that during pregnancy the intestine can grow dramatically causing the mother’s body to store more fat.
Dr Irene Miguel-Aliaga, head of the Gut Signalling and Metabolism Group at the MRC Clinical Sciences Centre, and lead author of the study, said “Previous studies have shown that eating for two during early pregnancy is unnecessary. Our research suggests that this is because the digestive system is already anticipating the demands that the growing baby will place upon our body.”
Indeed, the study has indicated that a fly hormone, called ‘juvenile hormone’ triggers changes in the intestine and fat metabolism in a similar way to human thyroid hormones, which are used to regulate the body’s energy demands. The study also suggests that if hormone levels fail return to normal after birth, a mother’s intestine may remain abnormally large, so she will continue to extract extra energy from her food - which is why some women may find it particularly difficult to lose weight after pregnancy.
Dr Jake Jacobson, co-author of the study, added “Many of the fly genes that we studied exist in humans. Flies also utilise and store fat like we do, and their metabolism is controlled by similar hormones.”
Dr Joe McNamara, Head of Population and Systems Medicine at the MRC, added: “Studies in fruit flies have been very valuable in providing insights into human physiology. This research points to a new scientific explanation why eating for two during pregnancy is not necessary, and may even be harmful, as a growing body of evidence indicates that a mother’s diet can impact a child’s propensity to be obese in later life. The important next step will be to reproduce these findings in humans.”