Do fats supply the most calories per gram?

Fats provide around 9 calories per gram with Proteins and Carbohydrates supplying about 4 calories per gram each.

Alcohol is the second highest provider of calories on a per weight basis. Alcohol will provide around 7 calories per gram. Not only that but your body will burn the alcohol first in preference to fat. This means that the fat gets stored away in all those places that you do not want it stored away in.