"There IS a reason we crave to eat and, once large, have trouble finding the engery and motivation to exercise."....................DenisetoAlaska
To this I say, "The difficult takes a long time to achieve, the impossible a little longer."
Metablolism changes throughout life. People who were once skinny are now fat without changing any of their eating habits. But the laws of physics do NOT change. The laws of conservation of energy do NOT change. And these laws state that for every calorie consumed, a calorie must be burned, or a portion will be stored.
I sympathize with obese people because their condition, whether self-inflicted or not, brings difficulties to their lives. However, there is a cure for it and they have an alternative.