Nothing beats eating less calories than you expend. The rest is mumbo jumbo.
A fatso torturing himself in the gym is a heart attack in a making.
Yes and no. Some people really gain weight eating little more than 1,000 calories a day and actually reach a plateau at which they cannot lose more weight eating even less than that. Many fat people merely eat everything in sight, but there are some whose metabolism is such that keeping weight down is difficult to virtually impossible. This can be a serious problem, because being overweight puts health in serious jeopardy.