However, fasting isn’t for everyone. Here are the pros and cons of the two main types of fasting.

  1. Alternate-Day Fasting: On fast days, you can eat only 500 calories. Alternate days have no food or calorie restrictions. Pros:

Eat what you want, every other day.You only have to count calories on your fast days.The method is well-tested and proven safe and effective in numerous human trials.Fasting every other day decreases cholesterol, triglycerides, and blood pressure.You’ll burn more body fat than you would with daily dieting.

Cons:

Limiting yourself to 500 or fewer calories every other day may leave you with low energy on fast days.You might get headaches and have difficulty sleeping for the first week or more.Your fast days may interfere with your social life, and they’ll be tough to maintain if you’re cooking for a spouse or your family.

MORE: 5 Safe Ways To Try A Fasting Diet (And Why You’d Even Want To In The First Place) 2. Time-Restricted Eating: Limit eating to an 8- to 10-hour window—for example, between 9 AM and 7 PM. Pros:

Eat what you want during your window.No calorie restrictions: Mice on this diet lose weight even if they eat the same number of calories as mice allowed to eat throughout the day.The diet appears to reduce inflammation and improve brain function and blood pressure control.If you schedule your eating window for early in the day—say between 7 AM and 5 PM—that’s when your metabolism and blood sugar control are at their highest. This may help you burn calories more effectively and stay healthier.

  MORE: 7 Tricks For Eating Less Without Even Realizing It  Cons:

The limited window for eating can interfere with your social life.The most effective version of this diet—eating earlier in the day—would be difficult to maintain with a spouse and family.There are no studies in humans yet