The blood that is received from the intestine contains carbohydrates, fats, and vitamins and other nutrients dissolved in it from the food you've consumed.
For example, people living with anorexia usually restrict the amount of food they eat, while bulimia nervosa is an eating disorder characterized by recurrent binges and purges.
Much of what a pregnant woman encounters in her daily life—the air she breathes, the food and drink she consumes, the chemicals she's exposed to, even the emotions she feels—are shared in some fashion with her fetus.