I've been doing my own flavor of intermittent fasting. Basically, three days a week I eat less than 500 calories (usually Monday, Wednesday and Friday.) Three days a week I try to eat sensibly and healthily (usually Tuesday, Thursday and Saturday.) One day a week (usually Sunday) I relax and eat whatever I want, although I try to show a modicum of restraint and not turn it into "let's see how much food I can cram down my gullet in one day."

On my fasting days I usually don't eat much of anything until supper, when I'll have a really large spinach salad with low fat dressing and a little bit of meat like chicken breast in it. I'll let myself have a little cream in my coffee, and when I get home from work a couple of olives and a pickle as a snack.

Nine years ago I used this approach to drop 60 pounds. I kept it off for about three years, then my life fell apart due to health issues with family members. I'm a stress eater, so I kind of stopped caring and started gaining the weight back at a rate of about 10 pounds per year. Six years later I'm still dealing with the stress due to the family members, but now have the unhealthy weight on top of all that. I accepted that I have started down an unsustainable path of weight gain. It was time to at least try and fix the situation. Knowing that the above method of eating was effective for me in the past, I went back to it.

Fasting takes discipline, but I actually find the fast days easier than the "sensible" days. It's simpler to give myself a mandate of "no food" than it is to get myself to "only eat a healthy portion."