Health nuts from Hugh Jackman to Tim Ferriss are trying 'intermittent fasting' - the dieting fad that lets you eat anything

An unusual diet is gaining traction among health nuts from Hugh Jackman to'4-Hour Workweek' author Tim Ferriss to startup workers across Silicon Valley. It's pretty simple, with no calorie counting or intense exercise regimen involved. Here's how it works in a nutshell: Just don't eat throughout the day.

When people practice intermittent fasting, they go without food for anywhere from 14 hours to several days. Some techies claim intermittent fasting helps them focus and be more productive, while others laud the diet as an easy weight loss hack.

Here's what you need to know if you're thinking about trying a fast.