Think fast

5 popular intermittent fasting methods and how they work

Here’s what they do to your body.


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Supporters of various intermittent fasting techniques swear by their method for everything from weight loss to cardiovascular health (though both of those claims are still being examined by scientists).

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But is there really a difference between methods like alternate day fasting, 5:2, and 16:8?

Here’s what studies have to say about 5 intermittent fasting methods:

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But wait — intermittent fasting isn’t for everyone. Before making a major lifestyle change, you should talk to your doctor.

Okay — now back to the list.

#5. 16:8

Eating within an 8 hour window daily and no eating in the other 16.

#5. 16:8

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Studies suggest modest weight loss in middle-aged adults on this eating pattern over the course of 8 weeks and a decrease in fat mass in athletes.

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Ultimately, 16:8 may offer any slight advantages to eating normally throughout the day, but more research is needed.

#4. 5:2

Eat normally 5 days a week and eat less food 2 days a week.

#4. 5:2


People with diabetes who tried this routine versus continuous calorie restriction saw comparable control over their blood sugar and similar weight changes.

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This and other studies suggest a 5:2 diet is a good alternative to traditional “eat fewer calories overall” diets.

#3. Alternate day fasting

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This is just what it sounds like: abstain from eating every other day.

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A 2016 review on studies of alternate day fasting day suggests it might be easier and more effective for fat mass loss than traditional calorie restriction.

#2. Eat stop eat

Fast once or twice a week for 24 hours.


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Periodic fasting is similar to 5:2 but requires complete abstinence from food on two days.

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The American Heart Association found this method less effective than alternate-day fasting for weight loss, but more studies need to be conducted overall.

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This method allows small meals of fruits or vegetables in the day and then one large meal at night.

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This method has been researched less, but a 2009 study on eating one meal a day found that, compared to the same amount throughout the day, one meal reduced fat mass but increased blood pressure and hunger.

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