A nutrient is a compound that is needed for normal function of the body.
There are six groups of nutrients:
- vitamins - compounds essential for normal physiologic processes in the body
- minerals - elements essential for normal physiologic processes in the body
Other compounds (for example alcohol) are not nutrients.
By needed amount:
- Macronutrients (nutrients needed in larger amounts): carbohydrates, proteins, lipids, water
- Micronutrients (nutrients needed in smaller amounts): vitamins, minerals
- Containing energy: carbohydrates (4 calories/gram), proteins (4 calories/gram), lipids (9 calories/gram)
- Containing no energy: water, vitamins, minerals