What is the nutritional importance of starches?
Starch is a member of the carbohydrates food group, which all have a caloric value of 4 kcal/g.
The study by Hardy et al., 2015  demonstrated the importance of carbohydrate consumption in human evolution. It supplies the body with energy and sustains metabolic functions (brain, red blood cells, fetal development, etc.).
Nutritionists agree that carbohydrates should be an important part of our diet. The European Food Safety Authority (EFSA) recommends that the intake of total carbohydrates, including carbohydrates from starchy foods (generally in the form of pasta, bready, tubers, or root vegetables) should range from 45-60 % of the total energy intake for both adults and children.
When consuming starch, the energy is released as our digestion breaks it down to its essential building blocks of glucose, using a series of enzymes first through our saliva, then further in our intestines.
The human body depends on the availability of glucose for essential parts of metabolism.
 Hardy et al., 2015. The Importance of Dietary Carbohydrate in Human Evolution.