Intermittent fasting (IF) is not a kooky eating trend:  are starting to understand that eating and restricting food according to circadian rhythms can result in weight loss and help those at risk of diabetes steer clear of the disease. Besides contributing to a slimmer body and a stronger immune system, intermittent fasting can also help your skin through detoxification.

Sameera Khan is a registered dietitian/nutritionist in the field of obesity. She’s also a physician assistant, podcast host, and nutrition professor.

In her book, Regain Be Gone, written for those who have experienced extreme weight loss and don’t want to gain it back, Khan describes intermittent fasting as a way to get all the nutrients you need in a limited timeframe while manipulating your metabolism. “Intermittent fasting or time-restricted eating tends to be effective for a lot of people because it is a passive way to lessen calorie intake,” she says. “And to lose body fat, you need to have a calorie deficit or use up more calories than you consume.”

Khan says IF helps your skin because, by restricting calories, you’re increasing your stem cells, which help boost cell growth and tissue homeostasis. Also, IF plays a major role in tissue homeostasis, anti-inflammation and cell growth. Acne, too, is often an “inside job.” Khan suggests pairing fasting with the elimination of trigger foods (typically, dairy and sugary foods, or foods that turn into sugar such as white bread, potato chips, and white rice). “At the end of an intermittent fasting cycle, one can identify foods that trigger the sensitivity of the skin by introducing back one food at a time and identifying the culprits,” Khan says. She also notes that a rare inflammatory skin disorder, Prurigo pigmentosa, can also be alleviated through IF.

Why IF Works

While human trials are still underway and not showing as many dramatic results as the studies of animals, IF has been shown to work, either by reducing caloric intake, improving metabolism, or both.

When you’re fed and full, your insulin is elevated, signaling the body to store excess calories in your fat cells, Khan says. But while you’re in a fasting state, your insulin is low and the body begins to burn fat for energy.

There are many versions of IF, and it’s OK to try several of them until you find one that works for you. The simplest schedules, Khan says, are the “12:12” or “16:8” strategies. In plain language, that means you’re restricting your eating hours to a 12- or 8-hour window per day. “The longer fasting period includes sleeping time, obviously, but you can still drink zero-calorie beverages like water, coffee and tea, as long as you don’t add sugar,” she says.

If you choose 12:12, you can set your eating window to start at 8 a.m. and end at 8 p.m., for example. With a 16:8 schedule, you’ll compress that, eating only between the hours of, say, noon and 8 p.m. There’s also a 5:2 version, which allows for normal eating five days of the week, but for the other two, you only consume 500-600 calories.

“This schedule may not be suitable for all, so the key is to select an eating window that is closer to your natural hunger period,” Khan says. “If you typically eat early in the day rather than late, move your eating window earlier. Also, consider your training or exercise schedule. We tend to be hungry right after training, so what you can do is eat a light, small meal before and after a workout so you stay in a neutral, not-hungry state.”

Another thing to note: Those with health issues including diabetes, eating disorders, mental illness or who are nursing or pregnant should not attempt IF without medical supervision.

Khan’s Steps for IF Success

Khan suggests starting your IF journey with these three steps:

1. Start by eating an early dinner and avoiding snacks for a few hours before going to bed. Push the first meal of the day back by an hour or so.
2. Plan your post-fast meal to contain protein, a vegetable, and a fruit. Avoid overeating and eat as if you never fasted.
3. Try scheduling your fast on a busy day so you benefit from not having to look for food. You will be distracted and less likely to have the urge to eat.

As with any health initiative, let common sense reign. IF isn’t a miracle cure for all that ails you. If you binge on high-sugar, bad-fat foods during your eating window, you won’t see the same results as if you followed a Mediterranean diet. You can also follow up with CoolSculpting to get rid of that last of your stubborn fat, then optimize results with ZWave and Alastin TransFORM Body Treatment.

“Intermittent fasting is an awesome fat loss tool and nothing else. It is basically how frequently you choose to eat and when,” Khan says.