A lot of fitness gurus are pushing the idea of intermittent fasting to help people achieve rapid weight loss. It seems like an easy, straightforward solution - fast one day per week to lose weight, and eat normal food the rest of the time.
Unfortunately, the research on the topic is a bit spotty. Some studies show that people who do IF tend to lose weight, while others show no difference at all.
The biggest problem I see with IF is that it is very hard to maintain over the long term. This means that most people will eventually gain all their weight back.
Intermittent fasting is great for short term dieting, but for long term success it doesn't hold up. This article explains why.
I do this from time to time