Step aside, Paleo and goodbye gluten-free; the latest diet trend doesn't just have you cutting out food groups, it has you cutting out food altogether.
Fasting has been around for thousands of years, mostly practiced historically for religious reasons, but modern dieters still turn to "just saying no" to food of any sort as a quick weight loss fix. Unfortunately, (according to WebMD) medical experts tend to agree that complete fasting (as in, not eating anything) is not a good weight loss strategy and should only be undertaken with a doctor's supervision.
The new trend, however, doesn't take fasting quite that far. Known as "restriction" or "intermittent fasting," science is starting to back up the idea that it's not what you eat, but when that matters most.
A study in the journal Cell Metabolism reports that when test mice were restricted in the times they were allowed to eat (and not restricted on calories, fat, or anything else) the result was leaner, healthier, more alert mice. The theory as to why this might be has to do with your hormones and an insulin-like hormone released when you eat that changes the way your body functions.
The very act of eating causes your brain to produce this hormone, so the only way to counteract it is not to eat. The research suggests that skipping meals and "starving" yourself a little every day, or a couple of times per week helps to keep your metabolism functioning properly.
A popular version of this is called the 5:2 diet, which is becoming popular in the UK, in which you eat three normal meals per day, five days a week and then, on two consecutive days, eat no more than 600 calories total.
And a researcher at the University of Illinois in Chicago recommends "every-other-day fasting;" in essence, you can eat whatever you want on the A days (yup: whatever you want) and on the B days, eat only 600 calories. In that study, subjects on the every other day diet improved their cholesterol and blood sugar levels, lost weight, and cut many other disease risk factors.