I left a link to a website which has some info from Joel Fuhrman's book. It also has a quote from the New England Journal of Medicine telling that fasting is excellent for weight loss. It also has an MD explaining that the fatter someone is, the less their metabolism slows down while fasting. The body is smart enough to know to slow down metabolism in a thin person but not in a very fat person.
Also the site has info on the stats of a study of people who did fasting to lose weight telling about the results later on. It was from HUP (U of Penn) hospital which is currently ranked as 3rd best hospital in the country behind Harvard U and John Hopkins U. Joel Fuhrman got his MD from U of Penn.
My chiropractor called him when he was having problems. He had him fast for 12 days (supervision over phone) and switch to a vegan diet. His health problems were gone in 3 months and he lost over 50 pounds.