My solution was the Aktin's Diet. It used to be very fashionable to bash it but an awful lot of recent studies have validated the basic approach. In the short term, you cut out nearly all carbs- initially you'll only eat about 20 grams per day. As you lose the weight you will start adding back the "good carbs," but to keep the weight off you really have to lose the bad ones. There's no diet I know of that allows you to eat a bunch of candy, soda pop, Dominoes pizza and milkshakes for every meal. The more processed foods you cut out the better off you'll be. Stick to real food, things that are identifiable on the plate.

I lost over 100 pounds this way, and have kept most of it of for around 10 years. Occasionally, maybe every couple years, I have a phase where I stray from the path a bit and put on maybe 15-20 pounds, but at the heaviest I've been I was still around 75 lbs lighter than my heaviest point pre-Atkins. It's harder to keep weight off as you get older and often more sedentary, but I find it's been easier to eat healthy. Partly it's just years of evidence of just how bad some of those foods are.

It's astonishing how much better you feel just taking 10-15 pounds off. Losing 100 pounds feels miraculous.