16-8 Hour Intermittent Fasting

16-8 hour intermittent fasting

16 8 Diet
Eat for 8 hours, then no eating for 16 hours

According to Hugh Jackman, the 16-8 Intermittent Fasting method of eating is “all the rage“. This system of eating is easy on paper – you eat all your meals in an 8 hour window, and then “fast” for the next 16 hours. Does this system really work? Is it really a fast? Will it help you lose weight faster? Let’s take a closer look at the 16-8 Intermittent Fasting method, often just called 16-8 IF, or the 8 hour diet.

First of all, let’s look at a typical eating pattern:


  • Breakfast around 7am – 8am
  • Lunch around 12pm – 2pm
  • Dinner around 5pm-8pm

An average person eats 3 times a day with some snacks mid-morning and mid-afternoon, with around 12 hours of eating followed by 12 hours of fasting (not eating).

The 16-8 method just squeezes the eating window down to 8 hours and stretches the fasting period. So if you follow a 16-8 fast you will probably skip breakfast and then have a large lunch, say at 12pm, then eat every 2 hours until 8pm, and then fast:

  • Lunch around 12pm
  • Protein based snack around 2pm
  • Protein based snack around 4pm
  • Dinner around 6pm
  • Protein based snack around 8pm

There are now several branded diets which use this eating method, one of which is the Leangains system which was created by Martin Berkhan. He has a degree in Medical Sciences and Education, but taught himself about optimum nutrition, partly through trial and error, while weight training to build muscle.

16 8 Fasting – Not Just About the Timing or Fasting

Following a 16-8 diet is not just about the timing. What you eat also needs to be chosen to meet your specific goals, whether you are looking to bulk up muscle or cut down fat. Read Peter Attia’s approach to diet to learn more about why you should be avoiding certain foods completely. Also take a look at how some top pro-bodybuilders eat before competitions.

Most people who follow this eating plan have 2 main goals:

  • Goal One: Losing Fat
  • Goal Two: Gaining Muscle

Diet, as in what is eaten, is as important, if not more important, than the timing of meals. Key rules are to limit sugar, cutting out all refined carbs and eating low GI and highly nutritious vegetables and fruits. Also lots of protein is taken, with some meals being just a protein shake or BCAA supplement.

Variations on the Theme

There are also many variations on the theme. There is no biological reason to not eat for exactly 16 hours. In fact, some people are talking about 18-6, 19-5 and 20-4 intermittent fasting now. A 4 hour window is very restricted, but you can still manage a large meal at 12pm, a snack at 2pm and then another large meal at 4pm, and get enough energy to fuel muscle growth. However, it will become harder to manage. Some people reduce the eating window to just 4 hours, and do a 20 hour fast, while others make a compromise and reduce to 6 hours, doing a 18 6 diet fast.

Intermittent Fasting 16 8 – Is It Really A Fast?

Although this is really academic, it should be noted that this is not really a fast in the strict meaning of the word. Although there is no actual minimum time set for an official fast, it is generally accepted that to fast means to not eat for a whole day, and not to consume 5000 plus Calories over the course of two-thirds of a day.

Even the 5:2 intermittent fasting method, which sets 2 days a week with only 600 Calories a day, is not a real fast, as 600 Calories is a lot more than no food at all. Real fasts are of course not suited to those who are trying to get fitter and more muscular, and do not provide a sustainable method of weight loss either – in short, they are mostly pointless.

Combining 5:2 and 16:8

Some people are also combining the two IF diet methods with good results. This is usually done by following a 16-8 diet during the week (when working Monday to Friday) and then the 600 Calorie “fast” over the weekend.

Old Advice?

Is this all really new though? For many years weight loss experts have said that eating no carbs after 6pm is a good way to control weight. It may be possible that just by avoiding all carbohydrates (even healthy low GI fruits and vegetables) for 12-16 hours a day you induce ketosis and burn more fat.

16 8 Diet Results – Test, Analyse, Review


Many people ask, does the 8 hour diet work? Really the same rules apply to a 16-8 diet – you should keep a diary and log all meals and measure your vital statistics (e.g. waist, chest, thighs and total weight) and check your progress each week to see if you are on track to meet your weight loss or fitness goals.

Whatever diet plan you chose to follow, do not fly blind – set yourself specific goals, have a plan and measure your progress, and then adapt to changes as you progress. This is the key to maintaining a healthy body weight in the long-term.

More Resources on Intermittent Fasting

The power of intermittent fasting – BBC News, 5 August 2012

16:8 Intermittent Fasting (IF) – 4 week experiment – Bodybuilding.com, 2012.

Intermittent fasting and Leangains – LeanGains.com, April 14, 2010

19 Comments on “16-8 Hour Intermittent Fasting”

  1. Russell Bell says:

    Intermittent fasting has worked wonders for me and allowed me to get to a single digit bodyfat level very quickly. I had always been fit but had trouble with stubborn fat and water retention. I like to do 16 – 8 for my fasts and I follow a cyclical ketogenic diet while fasting. If my goal is to build muscle quickly while getting lean, I’ll follow a carb backloading diet while fasting. These two methods have literally changed my life. Awesome post

  2. JR Hoffman says:

    “Real fasts are of course not suited to those who are trying to get fitter and more muscular, and do not provide a sustainable method of weight loss either – in short, they are mostly pointless.” Complete and utter rubbish. Simply look at research on fasting, OP. Do your homework before making such ridiculous statements such as this.

  3. MotleyHealth says:

    Feel free to give examples JR. By real fasts we are talking about not eating anything for at least 24 hours, usually a few days. Weight loss is no problem, but there is always a risk of muscle wastage when fasting. Taking 500 Calories a day or protein powders does not count as real fasting. IF is not a “real” fast, as food is taken every day.

  4. I agree with JR. If you do the research you will realise that short term fasting cycles do not put you at risk of muscle wastage. Since your post is dated 2013 I hope you’ve had some time to look into it properly. The benefit is that you will use all of the glucose in your system and then turn to fat stores for fuel. There are other benefits as well including reducing insulin resistance, detoxifying your body through the elimination of dead and damaged cells as well as many others leading to the reversal of high cholesterol and metabolic syndrome in many people. You would have to fast for weeks on end to have muscle wastage occur. These brief periods of fasting will give you the benefits without the potential damage of long term fasting.

  5. I found out about the 16:8 eating plan a month ago and have found great success with it. I am down 9 pounds and the good news is, I don’t think about eating anymore. Once I put that piece of fruit in me around 11:30/12:00 noon to break the fast I start my meals; a healthy breakfast and then a snack which is usually a piece of fruit or some cottage cheese and then dinner. I don’t crave sweets anymore and feel so much better now. I am a pretty active 58 year old female whose weight has been hovering about 20 pounds too much the last 10 years. For some reason which I assume it is my metabolism has slowed down those 20 pounds have been a bear to shake off. I feel this is a very promising way of eating for me and hope others will give it a try.
    Susan, Richmond, VA

  6. MotleyHealth says:

    Hi Susan, it always gets harder as we approach our goal weight. Just stay healthy, keep active and you will get there.

  7. I never heard of the 16-8 and just on my own started my own version, mainly because it’s easy for me to not eat during the day. I never had more than snacks then anyway. Mine is no food before 5pm, and only from 5 to midnight. So it’s a 17-7. But I eat whatever I want, especially carbs. Lost about 15 so far from 175 to 160 over 2 months. Honestly most days I do start growling early afternoon but that’s shrinking my stomach. So then when I do eat I don’t really load up like I used to. Probably consuming between 1600 and 2500 calories. this is just stage 1. Now that I got this down next stage is to eat healthier. Just need to go down another 15 to be lean and I’m prepared to get there in 10 months. Of course I started running again 5 days a week to help speed the metabolism and burn a few calories.

  8. MotleyHealth says:

    Interesting Mike. Are you exercising too? What time and what type of exercise?

  9. Hello, I was just wondering if this diet still works if I do it 5 days a week instead of 7, and are you allowed alcohol at all during the 8 hours?

  10. MotleyHealth says:

    Hi Olivia, it will still work, while you are fasting. No, alcohol is not allowed – alcohol = energy.

  11. Helllo,

    My mate just started this diet this week and I wanted to try it as well. The first two days were very hard to follow but I did it. My question is during that window mine is 11am-7pm what are the best options to make a good choice of food to eat and if my goal is to loose weight.? Please advice thank you

  12. Can you drink during your fasting time?

  13. MotleyHealth says:

    Yes Tina, fasting refers to food, not water.

  14. On the 16/8 fasting I prefer breakfast and lunch what times can I use? I am a morning person so not having dinner is great for me

  15. MotleyHealth says:

    Hi Sharon, you can eat between 6am and 2pm, or 8am and 4pm, which hopefully gives a convenient time for the two meals.

  16. Hello, are you allowed to drink alcohol during your feeding window?

  17. MotleyHealth says:

    Yes Olivia, if you wish

  18. i have a question. im so new to this and i dont get the 16-8 but right now its 11pm i was counting the next time i eat . so would that be around 3pm?

  19. MotleyHealth says:

    Hi Jazz

    You have an 8 hour window for eating everyday. When you eat depends on your lifestyle really. For example, if you have breakfast at 8am every day, then you last meal of the day would be 8 hours after that, which is 4pm.

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