Nutrition is the science of how the body uses food. You could say that nutrition is life. We all need food and water to live. In addition, to live well, we also need food with the proper nutrients.

In this section we briefly introduce a few concepts related to nutrition. There are also sections with additional details in areas such as the digestive system, calories, carbohydrates, fat, protein, vitamins, minerals.

Energy and Nutrients

Energy provides the ability to do work. Almost every bite of food provides energy, even when it does not give nutrients. The amount of energy in food is measured in calories, which is the amount of heat produced when food is burned, metabolized, in the body’s cells.

Nutrients are chemical substances that our body uses to build, repair and maintain tissues. Nutrients also empower cells to send messages back and forth to conduct essential chemical reactions.

Food provides two groups of nutrients:

• Macronutrients. Protein, carbohydrates fat, and water. The daily requirements for macronutrients typically exceed 1 gram.
• Micronutrients. Minerals and vitamins. The daily requirements for micronutrients are smaller than for the macronutrients.

An essential nutrient cannot be manufactured in the body, i.e. we need to get it from food or supplements. Also, an essential nutrient is linked to a specific deficiency diseases. For instance, if we do not get enough vitamin C, we develop the vitamin C-deficiency disease scurvy.