Let’s take a look at energy expenditure.

I have often wondered about the effects of very low calorie diet. It's a fact almost all fail, starvation even medium term does not sound like a good idea to me. Have you ever wondered where the energy goes from the food (our fuel) ends up, and what is it used for. I found it interesting our liver burns up more energy than we use in physical activity such as work etc. I think this gives a good indication why exercise is not the best way to lose weight.

About 70% of a human's total energy expenditure is due to the basal life processes within the organs of the body. About 20% of ones energy expenditure comes from physical activity and another 10% from thermo genesis or digestion of food. So, with 70% of energy being used just to stay alive and only 20% of ones energy available for physical activity.

Chart taken from and more info here

Eddie