About five years ago -- while working at a major magazine -- I witnessed a coworker engage is some especially unusual eating behavior. Some days she'd have pasta for lunch and gobble up every cookie on the freebie counter. Other days, she'd pick at a pile of grapes on her desk.

Within a month, she'd dropped two dress sizes. "Oh, it's the EOD diet," she said. "Every other day. You eat whatever you want every other day, and on alternate days you eat less than 500 calories -- I have grapes." Hmm …

She stuck with the diet for months -- hoarding desserts in the office fridge for her "eating" days -- and dropped a considerable amount of weight. But I wondered if it was actually a realistic way to live -- or a healthy one.

Well, the latest best-selling diet book is based on the same principle -- and some researchers think it works, and that it's good for you. It's called The Fast Diet, and it promises the same freebie-table-cookies-gorge-fest my coworker enjoyed, plus only two days a week of fasting (instead of three or -- ugh -- four). The key is spacing out the days to keep your body from going into starvation (fat-storing) mode. And some scientists think this type of diet may even help with cognitive function and delay aging. Can we say, "sold"?

But it's not all good news: "Anyone with disordered eating -- they know who they are -- may take two days of fasting to mean an entire month of fasting," nutritionist Dana James said in a wellandgoodnyc.com article about the book. She also said that eating anything you want is a stretch, and that you should stick with healthy food.

What do you think? Would you try The Fast Diet?

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