There are a lot of diets and methods for weight loss, but one of them that stands out among the rest is intermittent fasting. Instead of coming with a long list of foods that can or cannot be consumed and a number of calories that must be stuck to, intermittent fasting is less about what to eat and more about when to eat … and, most importantly, when not to eat.

Though there are several different methods of doing intermittent fasting, they always involve going a period of time without consuming anything but calorie-free liquids before breaking the fast for a limited period. In combination with exercise and making other healthy choices, this can definitely be a viable way of healthier living — and aside from weight loss, it can potentially come with a whole list of other health benefits, too.

Read on for the key points to know about intermittent fasting before jumping in headfirst to this popular method of weight loss and eating. It’s definitely not for everyone — especially when it comes to those of us who love to snack all day long — but for some, it really has been a game-changer.

Intermittent Fasting Isn’t a Diet

Because intermittent fasting doesn’t come with guidelines about what to eat, it’s not a diet — it’s classified as an eating pattern. It’s all about when the eating takes place, and those who take place cycle between patterns of fasting and eating, according to Healthline.

It Can Help With Weight Loss

Healthline reports that intermittent fasting helps weight loss along by not only reducing the number of calories that are taken in throughout the day, but also by burning more, too — this method is thought to increase the metabolic rate while causing less muscle loss than other methods of weight loss, which can definitely be a bonus.

The 16/8 Method is the Most Popular

Many people choose to start intermittent fasting with the 16/8 method, which is the simplest. According to what dietitian Dana Hunnes told Women’s Health, the 16/8 method includes eating for eight hours of the day while fasting for 16 — and those 16 would normally include the sleeping hours.

“Recent studies indicate that you might lose weight on this diet because when you fast, you are burning more fat for energy than you are carbohydrates,” she said.

The Eat-Stop-Eat Method Includes a 24-Hour Break

Another method of intermittent fasting is the eat-stop-eat method. With this method, people would fast once or twice a week, and during each fast, they’d abstain from food for a full 24-hour period. These fasts should not take place on consecutive days, and on days between the fasts, people should aim to take in 2,000 to 2,500 calories.

The 5:2 Method is Very Simple

The 5:2 Method of intermittent fasting is simple, and it’s popular because of that. For five days of the week, people using this method eat as they normally would, and for the other two days, they’d keep to eating just 500 to 600 calories per day. There are no specific foods that should make up those days; that’s up to the individual person.

OMAD Is Another Method

OMAD — or “One Meal a Day” — is another method of fasting in which people eat all of their calories in just one meal a day (duh). There are no restrictions on how many calories may be eaten during that meal, just that it makes up one hour of the day, while the remaining 23 hours of the day are for fasting. This is controversial, though, and experts have told Women’s Health that many doctors don’t recommend it as it’s considered a starvation diet.

Liquids May Be Consumed

During a fast, intermittent fasters are allowed to drink liquids that are calorie-free. This would include black coffee and tea without milk or sugar, water, and sparkling water without anything added to it. Staying hydrated while fasting is important, and it can help pass the time.

The Timing Matters

According to researchers at Harvard, the time in which we break our fast may effect how many calories are burned. According to Dr. Deborah Wexler, it’s best to eat earlier in the day, between 7 a.m. and 3 p.m. or 10 a.m. to 6 p.m., and to avoid breaking the fast right before going to bed.

Certain People Shouldn’t Fast

Intermittent fasting isn’t right for everyone. According to Everyday Health, people who should avoid fasting or who should consult their doctors before they do include pregnant and breastfeeding women, people who have struggled with eating disorders, people with diabetes or other chronic illnesses, elderly people, and underweight people.

It Has Potential Health Benefits

Besides the benefit of weight loss, there are other potential health benefits that come with intermittent fasting, like improvements in heart health, memory, and physical performance in athletic activity.

“Many things happen during intermittent fasting that can protect organs against chronic diseases like type 2 diabetes, heart disease, age-related neurodegenerative disorders, even inflammatory bowel disease and many cancers,” neuroscientist Mark Mattson told Hopkins Medicine.

It May Help Reduce Blood Pressure

According to Scientific American, a study of prediabetic men showed that reducing eating to a six-hour window each day ending at 3 p.m. showed better insulin sensitivity and blood pressure — go figure!

It Comes With Drawbacks

Intermittent fasting isn’t a magical weight-loss solution — it can be really difficult to stick to, and as Harvard researchers told CNN, in the beginning, people become hungry and find it difficult to concentrate because of that hunger. Feeling like they overcame something also makes them want to reward themselves, which can lead to overeating when they break their fast, too.

The Body Adapts to Fasting Quickly

If intermittent fasting is difficult from the beginning, there’s good news: According to Dr. Mattson, the body does adapt.

“Patients should be advised that feeling hungry and irritable is common initially and usually passes after two weeks to a month as the body and brain become accustomed to the new habit,” he told CNN.

It All Goes Back to Natural Selection

As epidemiologist Benjamin Horne told Time, the reason intermittent fasting works goes back to natural selection and evolution.

“You think back to long ago, when food gathering and production were not what we have today, and people would go extended periods of time without eating,” Horne said. “The people who survived to have children were individuals who were able to survive those periods, so just from that perspective, you would expect fasting would have an effect to improve health.”

Always Discuss With a Doctor First

Before making any dramatic diet or lifestyle change like intermittent fasting, make an appointment to hash things out with a doctor who knows if this is a solid choice, based on personal health history. It’s definitely better to be safe than sorry, especially when health and well-being are at stake!