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.

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.

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.

Test, Analyse, Review

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

More like this in the Diet and Nutrition section

  13 comments for “16-8 Hour Intermittent Fasting

  1. Ariel
    November 10, 2017 at 7:13 pm


    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

  2. Tina
    February 6, 2018 at 11:28 pm

    Can you drink during your fasting time?

  3. MotleyHealth
    March 6, 2018 at 12:12 am

    Yes Tina, fasting refers to food, not water.

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