This list is a categorization of the most common food components based on their macronutrients. Macronutrients can refer to the chemical substances that humans consume in the largest quantities (See Nutrient);

Macronutrients that provide energy

There are three principal classes of macronutrients: carbohydrate, protein and fat. Macronutrients are defined as a class of chemical compounds which humans consume in relatively large quantities compared to vitamins and minerals which provide humans with energy. Fat has a food energy content of 9 kcal/g proteins and carbohydrates 4 kcal/g. Water makes up a large proportion of the total mass ingested as part of a normal diet but it does not provide any nutritional value. Ethanol provides calories but there is no requirement for ethanol as an essential nutrient. Even though macros and calories are different concepts, they are dependent on each other. While macros refer to the three types of main nutrients that you need - protein, carbohydrate, and fat, calories, on the other hand, refer to the nutritional value of your meal.

Carbohydrates

Protein

Essential and non-essential amino acids

Fats

====Saturated (i.e., stable) fatty acids====

Monounsaturated (i.e., semi-stable) fatty acids

Polyunsaturated (i.e., unstable) fatty acids

Essential fatty acids

Macronutrients that do not provide energy

Oxygen

Oxygen is essential for life.

Water

Water is also essential for life. It provides the medium in which all metabolic processes proceed. It is necessary for the absorption of macronutrients and micronutrients but it provides no nutritional energy.

Fibre

Dietary fibre from fruits, vegetables and grain foods. Insoluble dietary fibre is not absorbed in the human digestive tract but is important in maintaining the bulk of a bowel movement to avoid constipation. Soluble fibre can be metabolized by bacteria residing in the large intestine. Soluble fibre is marketed as serving a prebiotic function with claims for promoting "healthy" intestinal bacteria. Bacterial metabolism of soluble fibre also produces short-chain fatty acids like butyric acid which may be absorbed into intestinal cells as a source of food energy.