The nutrients carbohydrates, protein, and lipids provide energy but water, vitamins and minerals do not.

Nutritionists recommend you get energy from a variety of foods:

  • 55 % from carbohydrates
  • 15% from proteins
  • 30% or less from lipids/fats

Food energy is measured in kilocalories (kcals), commonly referred to as calories. This terminology is technically incorrect, but is used so commonly that we refer to them as calories.

Fats, carbohydrates and protein can be seen with a microscope, but calories cannot be seen because it is not a thing. You burn energy, not calories, as calories are just a measurement tool.

A kilocalorie can be defined as the amount of energy needed to raise 1 kilogram of water 1 degree Celsius.

A food’s kilocalories are determined by putting the food into a bomb calorimeter and determining the energy output (Energy = Measurement of Heat Produced).

The table below lists the energy sources in the diet. Knowing these numbers allows a person to calculate/estimate the amount of calories the food contains if you know the grams of the different energy sources.

Energy (kcal/g) No Energy
Carbohydrates (4) Vitamins
Protein (4) Minerals
Alcohol (7) Water
Lipids (9)

As we can see, carbohydrates, protein, and lipids provide energy. However, alcohol can also provide energy. Remember that alcohol is not a nutrient but it does provide energy.

Originally published at allyfortisnetwork.wordpress.com