Among the nutrients, the amount of kilocalories per gram that each provide are shown below.
|Energy (kcal/g)||No Energy|
As can be seen, only carbohydrates, proteins, and lipids provide energy. However, there is another energy source in the diet that is not a nutrient……alcohol. Just to re-emphasize, alcohol is NOT a nutrient! But it does provide energy.
The following table lists the energy sources in the diet from lowest calories per gram to the highest calories per gram. 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 Sources (kcal/g)
Carbohydrates → 4
Protein → 4
Alcohol → 7
Lipids → 9
Bomb Calorimeter – https://www.learner.org/courses/chemistry/text/text.html?dis=U&num=Ym5WdElUQS9PQ289&sec=YzJWaklUQS9OeW89
Bomb Calorimetry – http://www.youtube.com/watch?v=ohyA9amFfsc