Intermittent fasting (IF) is having a seriously buzzy moment in the wellness world. Researchers and proponents say that various fasting techniques can help you live longer and ease symptoms of various health issues ranging from improving insulin sensitivity to helping to repair cells. But IF is *also* quickly becoming one of the trendiest ways to lose weight.

What is IF exactly? It centers around eating and fasting for specific periods, so you're blocking out specific times when you do not consume food. “Intermittent fasting is when you allow yourself to eat only during a specified window of time each day,” Alissa Rumsey, RD, a NYC-based dietitian and owner of Alissa Rumsey Nutrition and Wellness, previously told Women’s Health. (So maybe you eat between noon and 8 p.m. every day, or eat super low-calorie a couple of days a week.)

There’s no “right” way to do IF, and many variations exist. One is the 5:2 diet: On this schedule, most people eat less than 500 or 600 calories for two non-consecutive days per week. (So, you might have a 500-calorie day on Tuesday and Thursday, and then eat normally on Monday, Wednesday, Friday, Saturday, and Sunday.) With the 5:2 diet, you don’t need to eat certain foods—you just limit how much you eat during certain periods of time.

Another of the most popular variations is the 16:8 diet. "The 16:8 diet is where you eat for about eight hours of the day and then fast for the rest of the day," Dana Hunnes, PhD, RD, a senior dietitian at Ronald Reagan-UCLA Medical Center, previously told WH. Basically, during your 16-hour ‘fasting’ period, you limit yourself to black tea, coffee, or diet soda. Then, for the next eight hours, you can eat whatever you want (no calorie counting needed). That's it. Lots of fans also blend IF with the keto diet.

The thing is, intermittent fasting involves periods of not eating (duh, you get that). So it's not a great idea for everyone, such as pregnant women or people with a history of disordered eating. While weight loss can happen as a result of intermittent fasting for some, you should absolutely talk to your doctor about it first if you're curious.

Want hard evidence of IF's possible weight-loss effects? Just ask these 26 women below who tried IF (and some who paired it with keto!) and loved it—not to mentioned loved their weight-loss results.