Why is food transformed into nutrients?
The digestive tract transforms the food we eat into smaller elements, called nutrients, that can pass through the intestinal wall.

Some nutrients can pass through the wall of the digestive tract to be absorbed by the body directly. These include vitamins, minerals and some simple carbohydrates. Other nutrients are more complex and first have to be transformed. Lipids, for example, are transformed into fatty acids. Proteins are transformed into small peptides and amino acids. Finally, complex carbohydrates, such as starch, are transformed into simple carbohydrates such as glucose.