I agree with John, fasting is more a lifestyle than diet. It is great for maintaining, and many people use it for weight loss too. I fast a little differently from John. "Fasting" for me, involves 500 cal/day for female, twice weekly, and eat regularly (hopefully healthy) on the other 5 days of the week. You can break your 500 cals into two meals or just eat one. You can drink tea, water etc but no other cals during day.
It is not really very hard after the first couple weeks and it's nice not to have to count calories.