The 16:8 intermittent fasting protocol is the single most popular method of intermittent fasting because it’s highly flexible, relatively easy to start for beginners, and is a sustainable long-term approach to weight loss.
I don’t typically recommend 16:8 because from my experience there are better protocols to run if you know what you’re doing. This is however perfect for newbies and is a far superior approach to diet than what most people are doing!
So without further adieu, welcome to the single most comprehensive guide to 16:8 intermittent fasting on the internet!
What is 16:8 Fasting & How Does it Work?
In an 16:8 fast, the day is split into a 16 hour fasting window (typically around 7pm-11am) and an 8 hour eating window (11am-7pm). During the fasting window, you’re not allowed to consume any calories whatsoever and must consume all meals for the day within the eating window. This restricted eating window has been thought to have numerous health benefits.
Pretty self-explanatory right? Also,16:8 doesn’t technically come with any restrictions on what you can and can’t eat, so long as it’s within your eating window.
There are however a number of best practices you should keep in mind if you want to get reap the most benefits.
What Are The Benefits Of 16:8 Fasting?
Practicing intermittent fasting has a long list of benefits including fat loss, increased cognitive abilities, reduced inflammation, increased lifespan, and most importantly, less dishes to clean up!
This section of the article will look more specifically at the benefits of 16:8 fasting in comparison to other approaches to diet scheduling.
It’s The Perfect Introduction To Fasting For Beginners
If you’ve just discovered fasting then this is a great way to get your toes wet before moving into more advanced protocols that could yield better results. It’s the most similar type of fasting to what you’re probably used to doing, assuming you eat a few meals a day with snacks in between.
For most people, the major difference will be skipping breakfast which isn’t too challenging.
Massive Flexibility & Yummier Foods!
One of the cool things about 16:8 is that you can customize it however you like. You can move your 8 hour eating window around to suit your lifestyle and work schedule. Some people choose to fast from 7pm-11am whereas others will do 1pm-5am, it really doesn’t matter.
Compared to a normal diet plan, with a well constructed 16:8 diet you’re effectively just skipping a meal – so you can afford to be a little less strict on what foods you choose to include in your diet.
That doesn’t mean you should smash an entire tub of ice cream after dinner every night, because that will quickly defeat the purpose of fasting for health or weight loss, but you should be able to occasionally treat yourself and not feel too guilty about it.
Hunger and cravings can make things tricky at times when you’re living a fasting focused lifestyle.
However, since 16:8 allows a pretty generous 8 hour eating window, if you select the right types of foods, you should experience very minimal hunger!
It’s The Best Fasting Protocol For Athletes & Bodybuilders
One of the biggest problems I had with intermittent fasting as an athlete was losing muscle mass on certain fasting protocols.
When you fast for any extended period of time, the result is a drop in muscle protein synthesis, making it tougher for your body to repair and rebuild muscle tissue.1https://academic.oup.com/jn/article-abstract/112/10/1862/4754977?redirectedFrom=PDF
These effects are least noticeable in 18:6 fasting because athletes have more opportunities to consume high protein meals throughout their eating window, keeping muscle protein synthesis ticking over at an acceptable rate.
If you’re doing 20:4 or OMAD (one meal a day) fasting, you’re simply not able to spike muscle protein synthesis as often as you need to in order to hang onto all of your hard earned muscle.
One of the most common myths about fasting is that it actually promotes the maintenance of muscle mass because of an increase in growth hormone. But the reality is that with the lack of evidence supporting this combined with the findings of very recent research, there’s simply no proof of this being the case.2https://www.nature.com/articles/ejcn2015195
If you ask anyone who’s got actual hands-on experience fasting over long periods of time, the overwhelming amount of anecdotal evidence would tend to suggest that intermittent fasting has negative effects on lean body mass retention.
I remember 3 years ago personally doing a keto OMAD fasting protocol for 2 months. I was eating a single extremely high protein, high calorie meal everyday. I remember sitting there everyday just gorging on bacon and eggs and beef and fish for almost 2 hours every day.
I ate so much that I was barely in a calorie decific at all!
I was still working out 5 days a week but noticed I was losing muscle like crazy. I was getting plenty of protein in during my eating window, but still lost an unbelievable amount of muscle during that protocol, which is why if I had to recommend a fasting protocol for athletes, it would be something like 16:8 and not OMAD!
It Can Cause Faster Weight Loss Than Typical Calorie Restriction Diets
I should probably make the disclaimer that “individual results may vary”, based on your approach to fasting.
At the end of the day weight loss comes down to no. calories you eat – no. calories you burn. That’s true whether you’re fasting or on a normal calorie restriction diet.
The reason 16:8 fasting can be better for weight loss than typical dieting is because you’re physically not allowed to eat until a certain part of the day, the thinking is that this may cause you to eat less throughout the day.
It Can Make You Sharper Mentally
This has to be my favorite ‘side-effect’ of fasting. When you’re in a fasted state, you will no doubt experience bouts of laser like focus and the ability to think deeper without getting distracted for longer.
As someone who works online for a living, starting my work day off in a fasted state made a hugely positive impact on my career.
Studies have shown that the hunger hormone ‘ghrelin’ is actually able to stimulate brain cell development which may be one cause of improved cognitive function when fasting for short periods of time.3https://www.newscientist.com/article/2128695-hungry-stomach-hormone-promotes-growth-of-new-brain-cells/
Personally, I find I perform better cognitively on an empty stomach in part because my brain and body aren’t busily processing that food.
Have you ever eaten a huge carb rich meal for lunch and 30 minutes later just felt like you could pass out and sleep for hours? When you’re fasted, there’s no chance of falling into a food coma!
Admittedly, 16:8 isn’t the best fasting protocol for improving cognitive function because you’re missing out on tapping into the process of autophagy (your body’s cell/DNA clean-up system) which only really starts to kick in closer to 48 hours into a fast.
It Gives You More Time In The Day
One of the most understated benefits of fasting, in my opinion, is how much extra time you get in the day when you’re not having to think about cooking or cleaning up dishes.
Again this effect is more noticeable when you get closer to the ‘one meal a day’ type protocols where in some cases you’re getting hours of extra productive time in your work day because you literally don’t have to spend time eating!
If you’re a workaholic or someone who just wants some extra time for whatever side project you’re working on, you’ll definitely come to love this aspect of fasting!
What Are The Disadvantages Of 16:8 Fasting?
There are a few small drawbacks to be aware of when considering 16:8 vs other fasting and non-fasting approaches to eating.
Average To Slow Weight Loss
You’re not likely to lose as much weight as you could on a more aggressive fasting protocol.
If losing weight fast is your goal, there’s definitely going to be more effective approaches than 16:8. However, if you’re simply looking to make a step in the right direction, 16:8 is definitely still a great place to start.
It Still Requires Strict Diet Adherence For Best Results
The most common misconception beginners have is that they think they can get away with eating whatever, so long as it’s in the eating window, and still lose weight.
Unfortunately that’s not how weight loss works. If you’re only burning 2,000 calories each day, but you’re eating 2,500 calories in your 8 hour eating window, you will obviously gain weight.
In a protocol like OMAD (one meal a day), you actually can eat just about anything you like and you’ll lose weight – simply because it’s really difficult to eat more calories in a single sitting than you burn in a day.
It’s Occasionally Inconvenient
If your eating window is 11am – 7pm and a friend asks if you’d like to go out for breakfast with them at 9am, what do you tell them?
“Sure I’ll sit there and watch you eat!”
Perhaps your work schedule only allows for a quick lunch break at 1pm and you’re not getting home until 6pm. If that’s the case, you’d likely have to shift your eating window back a few hours.
It’s great that 16:8 is so flexible and that you can do this, but really any fasting protocol can get in the way of life sometimes.
16:8 Intermittent Fasting & Working Out
Exercising during either the fasting or eating window of a 16:8 protocol is highly recommended. Daily exercise is a large component of weight loss and is safe and advisable while following a 16:8 IF plan.
Yes, you should work out while fasting. You can workout after a meal or in a fasted state; there are benefits and drawbacks to both.
Unfortunately the research is inconclusive on whether working out fasted burns more fat than working out after a meal. So really you should just work out whenever is most convenient for you based on your schedule.
Who Should Do 16:8 Intermittent Fasting?
16:8 Intermittent fasting is appropriate for a wide variety of people aiming for moderate fat loss. It’s a highly effective introductory fasting protocol for people wishing to incorporate fasting into their routine without having to make major lifestyle changes.
It’s not only effective for overweight people but very popular among athletes looking to shed some body fat but maintain as much lean body mass as possible. Really anyone of any age can get started with this protocol.
Teeneragers and children should make sure they’re still getting plenty of calories in during their eating windows in order to facilitate proper growth and development.
Who Should Not Do 16:8 Intermittent Fasting?
The two groups of people who 16:8 fasting may not be appropriate for are athletes wishing to gain lean body mass, and pregnant or breastfeeding women.
Due to the reduced frequency of meals, there is a major dip in muscle protein synthesis throughout the day, making the repair and building of muscle tissue very difficult.
If your goal is muscle development, you’ll be fighting an uphill battle on any fasting protocol.
The second group of people is pregnant and breastfeeding women. While there is actually no research that calls into question the safety of fasting in these groups of people, it’s probably not going to be the optimal approach and you should do so with a high degree of moderation and caution.
My 16:8 Fasting Tips For Success
Having done 16:8 personally for over 3 months in the past, I have some valuable ideas that you should be aware of if you want to get the most out of this protocol.
Calories Are King – Control Caloric Intake
You want to avoid the trap of thinking that just because you’re fasting you’re going to lose weight. It doesn’t work like that. You need to be in a caloric deficit to see any weight loss at all.
Calculate your total daily energy expenditure (TDEE) to work out how many calories you should be eating to maintain your current body weight. And then subtract 200-500 calories from that amount depending on how aggressively you want to lose weight.
Then all you need to do is plan out a few meals to reach that calorie target and stick to it!
This should be made easier by fasting since you probably only need to eat about 2-3 big meals in the 8 hour window.
Choose Low Caloric Density Foods To Avoid Getting Hungry
This is the secret sauce.
The single best way to lose fat and without running into serious hunger issues, is to choose ‘high volume, low calorie’ foods. Foods like this are high in fiber which naturally contain way less calories for the same amount of food volume.
My recommendation is to try to include as many of the following foods into your diet as possible.
- Lettuce and salads (hold the dressing)
- Watermelon, cantaloupe, strawberries – Absolutely incredibly low calorie fruits. You can eat a ton of them without consuming a ton of calories. Also a great way to get the vitamins, minerals, and other goodness you’ll need.
- Popcorn (without the salt or butter) – It sounds kind of goofy, but if you can find plain, unflavoured, unsalted popcorn, this is the ultimate snack when you’re trying to lose weight. This is an often used trick of bodybuilders are cutting weight in preparation for a show. When compared to more popular forms of carbs like bread or rice, popcorn contains not only less calories, but it’s actually really difficult to eat too much of it because it’s so light and fluffy. It’s like eating air. This forces you to eat it slowly. When you eat things slowly, you give food a better chance to settle in your stomach before sending the signal to your brain that you’re getting full.
If you base your 16:8 IF diet around the above foods, you’ll almost certainly never get hungry because you can eat a massive amount of food and still be in a caloric deficit.
We also want to avoid high fat foods if possible – 1 gram of fat contains 9 calories, whereas 1 gram of carbs or protein contains only 4 calories. Mathematically, you can consume more food (which will make you feel fuller for longer) if you only eat carbs and protein.
Opt For A Keto Diet For Maximum Fat Loss
When you starve yourself of carbohydrates, you can engage a metabolic process called ketosis which is where the body shifts gears from burning glucose to burning fat as its primary fuel source.
Studies have shown that being in ketosis can increase the rate of fat loss compared to typical calorie restriction methods.4https://pubmed.ncbi.nlm.nih.gov/12679447/ It’s not for everyone, but well worth trying out if you’re looking for big results.
Keto is pretty simple to follow and involves eating only protein and fat, and barely any carbs. It’s also a very popular diet plan to use while following any intermittent fasting protocol – they go hand in hand.
You’ll be able to easily find plenty of great resources with keto recipes and food ideas online.
Don’t Expect Too Much
As I’ve said many times earlier, 16:8 is a beginner fasting protocol. The weight loss results you get out of it are going to be almost completely determined by how big of a calorie deific you’re in and not so much the fact that you’re fasting 16 hours a day.
For excellent results, you still need to be extremely disciplined in which foods you choose and you need to give it time.
It’s quite common for people to start 16:8 and actually gain weight at first.
People often miscalculate how many calories they should be eating, or simply cheat and eat outside their eating window.
The formula for success is really simple. Eat less calories than you burn + eat only in the eating window. If you do that, it is physically impossible not to lose weight!
16:8 Intermittent Fasting Schedule Example
The most popular schedules for 16:8 intermittent fasting have the eating window starting at around 10-11am extending through til 6-7pm, as this aligns with our natural circadian rhythms.
I’ve shown this visually below so you can get an idea of what your weekly schedule would look like following the 16:8 protocol.
The freedom is completely yours to place your eating window wherever suits you best.
You can’t however break the window into 2 smaller 4 hour eating windows, for instance, as this will interrupt the metabolic processes we’re trying to engage by fasting for 16 consecutive hours.
Best Alternatives To 16:8 Fasting?
The best alternative to a 16:8 fasting protocol will be heavily dependent on the requirements of each individual. For many, the next logical step will be increasing the duration of the fasting window to an 18:6 or 20:4 protocol. For others, not fasting at all may be more appropriate.
If you found that 16:8 wasn’t a great fit for you, you need to ask yourself what went wrong. Why wasn’t it wasn’t working out?
Did you struggle to stick to the eating/fasting windows? Do you simply eat too much? Here are some common complaints and logical next steps to take.
[blockquote align=”none” author=”Jenny”]I found I wasn’t quite getting the weight loss results I wanted. The weight simply didn’t come off like I thought it would.[/blockquote]
- If adherence to your eating/fasting windows wasn’t an issue, you probably ate too many calories during your eating window. You could try 16:8 again, this time eating less overall calories.
- You could also opt for an 18:6 or even 20:4 approach. By further narrowing the eating window, it will be more difficult for you to overeat.
- You could try 16:8 or 18:6 but this time eat a keto diet.
[blockquote align=”none” author=”Joan”]I heard that fasting could help with my skin condition. I tried 16:8 for a month but didn’t notice any difference.[/blockquote]
- Consider attempting a prolonged fast such as a 3, 5, or 7 day water fast. These extended fasting protocols engage powerful bodily healing processes which deeply cleanse and repair damaged organs, including the skin.
[blockquote align=”none” author=”Jimmy”]I did 16:8 for 3 months and found I was losing fat like I wanted to, but getting weaker in the gym.[/blockquote]
- If your goal is to get bigger and stronger while still losing fat, forget about fasting for the time being. Eat 5-6 meals per day, each with at least 20g protein in them throughout the day (to maximize muscle protein synthesis), while maintaining a very slight (100-150g) caloric deficit.
Below are a few commonly asked questions about the 16:8 fasting protocol. If you have any additional questions, please ask them below in the comments and I’ll get back to you ASAP!
How much weight can you lose on a 16:8 diet?
Following a 16:8 fasting protocol, if also in a 500 calorie daily deficit, you can expect to lose roughly 1lb (0.45kg) per week.
There is roughly 3,500 calories in a pound of fat. If we’re burning 500 calories more than we’re eating each day, every 7 days we’ll burn close to 1lb of fat.
Of course we can increase or decrease the rate of fat loss by changing how many calories we eat each day.
It should also be noted that when we start losing weight, our basal metabolic rates will slow down, meaning eventually we’ll need to cut additional calories in order to continue losing weight at the same rate.
Merely fasting alone doesn’t help us burn more calories, but it does speed up metabolism somewhat which will enable us to continue losing fat consistently without having to make as frequent calorie cuts.
Fasting also promotes insulin sensitivity which will help prevent us from storing additional body fat.
What can I drink when doing 16:8 intermittent fasting?
Water, black coffee, black, green, or herbal tea, as well as diet soda are acceptable to drink on an 18:6 fast because they contain virtually no calories.
That being said, it’s best to avoid the calorie free carbonated drinks altogether if possible. Really you should mostly be drinking water during your fast. A small splash of milk in your unsweetened tea or coffee is also acceptable.
How long to do 16:8 fasting?
Intermittent fasting is a lifestyle choice that can be practiced for the rest of your life. There is no reason to stop an intermittent fasting protocol unless you feel as though you could improve results with a different approach.
This isn’t a 10 week program or a fad diet. Intermittent fasting is a lifestyle choice and you can do it for as long as you like!
Tell Me About Your Experience With 16:8!
Hopefully I’ve equipped you with everything you need to know to start 16:8 intermittent fasting as soon as possible. If you’ve already begun or have been doing it for a while, I’d love you to share with me how it’s going, what you’re struggling with, and what you like most about it.
Don’t hesitate to drop a comment below!