It is a fact that some people can eat as much as they like and what they like without gaining an inch or an ounce. Also there are those who, having gained the weight, cannot shift much of it no matter how much exercise and healthy eating they do. However, and i speak as one to whom this once applied, the majority of obese people have arrived at that door through lack of exercise and poor diet. At my heaviest, i tipped the scales at 18 and a half stone. I didn't eat all day when working, would visit the pub immediately after work and quaff ale until i was hungry - always got the 'munchies' off beer - then call at the 'Chinese' on the way home. Having eaten said Chinese, i would normally have 2 bars of chocolate as dessert! And i smoked like a factory chimney. The inevitable heart attack happened, i changed my way, ate far more healthily, took regular exercise and lost just over 6 stone. Gained about 3 of that back, since, but still on a healthy diet. For many, obesity is caused by the wrong life choice.