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What is 16:8 Intermittent Fasting?

What is 16:8 Intermittent Fasting, and Should I Do It? Here's What You Need to Know

If you've heard about the benefits of intermittent fasting (IF) such as weight loss (including stubborn belly fat), decreased sugar cravings, more energy, improved mental clarity, reduced inflammation, disease prevention, and better sleep, you're bound to be inspired to try it. For beginners, the 16:8 protocol (also called Leangains) is a great method to start with.

What Is It?

Made popular by fitness expert Martin Berkhan, this method of IF involves a 16-hour fasting window and an eight-hour feasting window. An example would be to skip breakfast and then eat from noon until 8 p.m. During the feeding window, two to three meals are consumed, consisting of healthy, whole foods.

How Does 16:8 Help With Weight Loss?

Certified dietitian Leslie Langevin, MS, RD, CD, of Whole Health Nutrition says that intermittent fasting could be another tool in your belt to help with weight loss or to break through a weight-loss plateau.

Leslie says, "It gets your body out of 'storage mode' and mobilizes fat stores for energy." This means that without having the constant source of food (fuel) you'd get from eating all day, your body will dip into the fat it already has stored. That's why people find so much success losing weight with intermittent fasting. Because this is healthy and easy to sustain every day (and for years to come), the 16:8 protocol is the method Leslie recommends to her clients.


You can set up your eating and fasting windows based on your schedule. If skipping breakfast doesn't work for you, maybe eat from 7 a.m. until 3 p.m., and skip dinner instead. You can also alter your eating window if you have plans or a party to go to. You're allowed to drink black coffee and tea during your fasting window, and the caffeine can help curb hunger, making fasting effortless.

Since you're consuming all your daily calories within a shorter window, another pro is that you can sit down and eat larger meals, feeling more satiated than if you were eating three small meals throughout the day. You have more leniency with the foods you eat as well, so you can choose higher-calorie or higher-carb foods you may have denied yourself before. And even if you skip breakfast, you can still eat the breakfast foods you love, you'll just be delaying your meal until lunchtime.

Once you get past the first week of fasting, you won't even feel hungry, and you'll wonder why you were eating that meal all these years! You'll save money and time buying and preparing food and be able to devote your brain power to other areas of your life. You'll feel less bloated, more clear-headed, and lighter in mind and body. The 16:8 protocol is easy to maintain in the long-term, especially to help maintain your weight once you reach your goal.


The first week or two sucks. There's no getting around the fact that you'll feel hungry, irritable, low in energy, and a little sad that you can't eat when everyone else is eating. But once your body adjusts, you'll feel amazing.

If you have a family, skipping meals may be tough, so you'll need to choose the easiest schedule. Since dinner is a big deal at our house, my eating window ends at 7 p.m. to allow for family dinners. You may also have to change your exercise routine. It may be too long to wait to eat at noon if you work out at 5 a.m.

One major negative to doing any form of intermittent fasting is the comments you'll get from other people who don't understand and who are used to the typical eat-all-day lifestyle we were all taught. So you may want to keep it to yourself for the first few weeks. Once people see the positive results and start asking what you've been doing, you can get on your IF soap box.


Like any new way of eating, there is an adjustment period. The best advice is to not dive right into 16:8. Begin first with 12:12, where you eat from 8 a.m. until 8 p.m., for example. Then gradually shorten your window, eating from 9 a.m. until 8 p.m., then push it to 10 a.m. and so forth until you're comfortable fasting 16 hours.

Make sure to get enough sleep, at least seven hours each night. Since you might feel lethargic and hangry in the first couple of weeks, you may want to go less intense at the gym, or trade workouts for walking, just until your body adjusts.

Remember that just because you skipped one meal, doesn't mean you can eat as much as you want during your feeding window. Choose healthy, nutrient-dense, whole foods. Eat until you're satiated but not stuffed, and focus on getting protein, healthy fats, complex carbs, and plenty of fibre.

Before starting any new diet plan, including intermittent fasting, be sure to check in with your doctor first.

Image Source: POPSUGAR Photography / Lexi Lambros
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