Fat...
Fat with 9 calories per gram
Most of Gram+ bacteria and for Gram- ones, Segnilliparus spp.
In food, there are three macronutrients that provide energy. They are fat, carbohydrates, and protein. Fat is the nutrient that provides the greatest amount of energy at nine calories per gram. Protein and carbohydrates provide only four calories per gram.
The most energy rich nutrient is fat. There are two other nutrients that produce energy for the body and they are protein and carbohydrates.
The most calorie-dense substance is pure fat, which contains 9 calories per gram.
Carbohydrates and fats are the two most commonly used molecules for energy in the body. Carbs burn at 3.75 kilocalories/gram and fats are roughly twice as energetic
Fat has the most calories per an ounce. There are 9 calories per a gram, so an ounce of fat has 255.06 calories.
Carbohydrate's I think.
Lipids store more energy per gram than carbohydrates or proteins.
Fat. More calories =more heat=more energy.
The forgotten nutrient and the most important is water.