Not so long ago in Medical News Today there was an interesting article, detailing how much change in the gastro-intestinal tract of a pregnant woman. The interesting thing is that change starts in early pregnancy and continues throughout the period of carrying a child.
First of all, the digestive tract increases and adapting to the new status of women, increasing the absorbability of food, which for the most part the majority of mothers are so hard to lose weight after the baby is born. The body, despite the fact that the birth had already passed and the need to "eat for two" is no more, continues to benefit from increased amount of food energy.
This theory is confirmed by long-term monitoring of fruit flies. In these insects after fertilization, the intestine sharply increases, and the body accumulates fats, thanks to the surge of hormones. It is noteworthy that found in fruit flies, the hormone has the same effect on insects just like thyroid hormone in humans. Thanks to him, is responsible for regulation of human demands for energy and changes in the metabolism of fats. By the way it also affects fertility. In particular, in flies it regulates changes in the digestive tract and the number of eggs in one clutch.