|Losing weight isn't that difficult. Keeping it off is where most diets fail.|
The first problem with dieting is that it's seen as a temporary event. If you view dieting this way you"re likely to gain any lost weight back.
To keep weight loss off you must make life time changes to your diet and exercise regimen.
To keep weight off you must monitor your weight every day. The difference is instead of losing a pound a week you want to stay below a certain weight. My current goal weight is to be below 160 pounds. Now I've gained four pounds in one day so if I want to stay below 160 I must not eat like crazy unless I'm below 156 pounds. To make sure I stay below 160 I'll set my goal at 0.2 pounds less. This way if I gain four pounds I'll be at 159.8 pounds, still be below 160.
Nothing should change with your weight loss method except your daily target. Manage against this number and you'll never gain weight back.