INTERMITTENT FASTING

The Hidden Truth About OMAD Without Keto? [Does It Work?]

With keto being all the rage these days, people are brought into the community and exposed to so many new foods, methodologies, and even meal structure.

I don't think you could be on keto for any reasonable amount of time without hearing about intermittent fasting (which is also catching wind by the mainstream). Inevitably, people start going deeper and deeper down the hole and ultimately find out about one meal a day OMAD.

For one reason or another, you may enjoy the structure of OMAD, and maybe you're looking to switch up your diet or implement some more carbohydrates, but can you?

Can I do OMAD without keto? You can do one meal a day OMAD style of eating using whatever diet or foods you wish to use. There is nothing about OMAD that would require you to be in ketosis and vice versa.

In this article, I'm going to dive a little deeper into what exactly OMAD is, what to eat, muscle and fat loss, IF vs. OMAD, and much more.

Can You Do OMAD Without Keto?

Intermittent fasting (IF) is an umbrella term in which OMAD falls under. Technically speaking, what most people refer to as intermittent fasting or one meal a day (OMAD) is regarded as time-restricted eating (TRE) in the scientific literature.

After some time on a ketogenic diet, you may have started to do some research on different ways to speed up your weight loss, which ultimately let you down the path of IF.

Once you go down the rabbit hole far enough, most people end up trying things like OMAD or multiple day fasts.

Naturally, there comes a time where you may want to transition off keto and wonder if you can still eat one meal a day without being on a ketogenic diet.

And you can, without a doubt.

One meal a day isn't reserved for implementation with a ketogenic diet only. You can manage to lose or maintain your weight loss using any form of diet or with additional carbohydrates.

What Is OMAD

OMAD is short for one meal a day.

It's just another form of time-restricted eating that allows people to eat their total daily calories in one meal, versus spreading your meals throughout the day.

Think of your daily calories as a “budget” that you are given at the start of each day.

You could make small purchases throughout the day, OR you could make one big purchase at the end of the day.

Why people choose to eat one meal a day

You may have found it easier or more convenient to implement intermittent fasting than eating smaller meals throughout the day, or maybe someone, somewhere, told you that intermittent fasting with the holy grail for fat loss.

After all, who likes to eat like a bird all day when you can eat like a king or queen at night?

And who doesn't want to expedite their results?

Although, whether you eat all your calories in one meal versus four meals will not make a considerable difference in terms of weight loss. 1

Outside of some possible health benefits or as a dietary adherence strategy, IF will not speed up weight loss to any significant extent. If you'd rather eat smaller meals throughout the day, this is your permission to do so.

Besides, most people are busy during the daytime and have most of their social or family obligations that occur during the evening hours.

You may also generally be more hungry during the evening and/or hate going to bed on an empty stomach, at least that's what sealed it for me.

Therefore, there's nothing synonymous with OMAD and keto. OMAD merely is eating in a time-restricted fashion and eating all of your daily calories in one meal.

Hence, “One Meal” A Day.

Can You Eat Anything On OMAD

At the end of the day, the most significant determining factor when it comes to weight loss will be your total calories.

Yes, despite what other “keto gurus” led you to believe. Insulin isn't as evil as people make it out to be.

While different macronutrients play a small role, total daily calories will have the most significant impact on whether you lose weight or not.

Therefore, while it still makes sense to eat whole, nutrient-dense foods, you can still lose weight if you're managing your total daily calories.

… and that's whether that involves you sticking to a low-carb ketogenic diet, or a more moderate carbohydrate diet.

However, for many individuals, they find the structure of a ketogenic diet easier to adhere to, feel better, and they're not constantly starving compared to other types of diets. 2 3 4

What To Eat On OMAD

So what should you eat if you want to OMAD without keto? Well, that depends on what you like to eat (within reason of course).

What I mean by that is, a diet shouldn't be based solely on foods that someone told you are “good” or “bad.”

Instead, try to implement foods you enjoy, within reason of course, while achieving your goals. This may mean making healthier substitutes or lower-calorie alternatives, but it's all for the greater good.

After all, how can you sustain a diet based on foods you don't enjoy?

Easy, you can't.

So instead of asking WHAT to eat, you first need to figure out how much to eat, then fit in what to eat based on that.

The only big suggestion I have here is to set your protein intake, then eat a mix of fat or carbohydrates based on your preference.

To learn more about setting up macros, you can visit the keto macro calculator.

Will You Lose Muscle On OMAD

When you lose weight, the goal shouldn't be ONLY to lose weight, but to lose fat.

Losing muscle can lead to a variety of negative consequences, but within the context of weight loss, it just means your metabolic rate will be slower.

There's also a higher chance you'll not have the physique you had imagined once you do lose the weight.

Therefore, one must be mindful and aim to preserve as much muscle tissue when dieting as possible.

Whether you lose muscle on OMAD is primarily determined on a few key factors, those being:

How fast you're losing weight (0.5-1.5% body weight per week)
How much protein you’re eating (~1g/lb) 5
Proper stimulus (resistance training)
How lean you are (the leaner you are, the more susceptible to muscle loss)
Lifestyle factors (stress, sleep, etc.) 6

There's a little more wiggle room when it comes to intermittent fasting or OMAD and weight loss.

However, if muscle GAIN is a priority, you could gain muscle doing OMAD, but it wouldn't be the most optimal way to do so.

IF vs. OMAD

Whether you choose to do IF using an eating window, such as 16/8 (16 hours fasting, 8 hours feeding), or consolidate all of your calories into one meal is solely based on preference.

Neither the typical IF eating windows or OMAD is superior for weight loss.

Therefore, if you enjoy eating 2 or 3 meals versus one big meal, the result will be the same.

Of course, results would only be the same if you ate the same amount of calories and protein spread throughout the 2 or 3 meals as you would the one meal.

OMAD would only be more beneficial versus the typical IF protocols for weight loss if it allowed you to sustain a more significant caloric deficit.

Is OMAD Healthy?

Current scientific literature suggests that intermittent fasting, which OMAD falls under, has beneficial effects on cardiovascular biomarkers, may decrease inflammation, and promote longevity.

However, it may be more beneficial if your one meal or eating window was during the earlier half of the day versus the evening time.

This method of shifting your eating window to the morning is referred to as “early time-restricted feeding (eTRF).

During a 5-week crossover trial, researchers using a feeding window from 7 am to 1 pm.

Compared to a control diet, the early time-restricted feeding window led to less insulin resistance, lower postprandial insulin response, and better beta-cell function. 7

In another stud, they compared a 9-hour feeding window from 8 am to 5 pm versos 12 pm to 9 pm, but no significant differences were found. The eTRF group had a slightly better fasting glucose. 8

If you're still wondering if OMAD is safe and healthy, you have the green light. Most of the benefits are health-related versus weight loss related.

Intermittent Fasting Without Keto… Can you lose weight intermittent fasting without keto?

While keto may make intermittent fasting or OMAD more natural to adhere to, you can do both IF or OMAD successfully without a keto diet.

A ketogenic diet may make it easier to adhere to a long fasting window due to its effect on satiety, but it isn't required.

I should also note that IF or OMAD isn't required to lose weight either. If fasting for such long periods causes you more stress and you prefer to eat smaller meals throughout the day, I would suggest you do that.

Read: Intermittent Fasting Without Keto? [A Better Approach]

The Takeaway

OMAD or one meal a day is merely a time-restricted feeding method often used by those who enjoy bigger meals over two to six smaller meals throughout the day.

While there is no inherent benefit for weight loss when it comes to intermittent fasting or one meal a day, this style of eating allows people who prefer it to adhere to their diets, and it fits with their lifestyle.

A ketogenic diet is not required to successfully implement an intermittent fasting or OMAD approach so long as calories are controlled.

Will Intermittent Fasting Slow Your Metabolism? [The Truth]

Intermittent fasting (or time-restricted feeding, as referred to by science), has become more prevalent in this past decade. For those following a ketogenic diet, it's almost inevitable that you'll eventually hear of and/or try intermittent fasting to optimize your results.

But one can only wonder what prolonged periods without food regularly might do to their metabolism.

Will intermittent fasting slow metabolism? According to the current scientific literature, intermittent fasting does not have any measurable effect on the metabolism, which includes resting energy expenditure and thyroid-stimulating hormone. 9

In this article, I'm going to cover what exactly goes into total daily energy expenditure (how many calories you burn daily), some of the current literature on IF, metabolism while EXTENDED fasting, things you can do to keep metabolism humming, and much more.

Does Intermittent Fasting Slow Metabolism?

A common concern among people who want to try or already implementing intermittent fasting (IF) is whether or not it will slow down their metabolism, aka starvation mode.

After all, that would be counterproductive to your weight loss goals, so I get it.

Over the decades we've come across so many myths and misconceptions, to name a few:

Eat breakfast to “boost your metabolism.”
Eating small meals every 2-3 hours keeps your “metabolism burning.”
Don't eat after a specific time, because it will lead to fat.

I had these very same questions, which led me to go down the rabbit hole of intermittent fasting.

First, let me start by saying that starvation mode DOES NOT exist, nor can you permanently damage your metabolism, which I'll get to shortly.

While there are specific processes in your body that do begin to slow down (downregulate), it's not WHAT and WHY you may think.

How To Calculate Total Daily Energy Expenditure

So here's the deal, long story short, to effectively lose weight you must burn more calories than you consume.

Despite what some guru has led you to believe.

If you didn't believe that, you wouldn't need to worry about a slow metabolism, but you're here.

How many calories we burn throughout the day is what's referred to as your total daily energy expenditure (TDEE). Your TDEE consists of four main components:

Resting Metabolic Rate (RMR)
Thermic Effect of Food (TEF)
Physical Activity (PA)
Non-Exercise Activity Thermogenesis (NEAT)

What Is Resting Metabolic Rate (RMR)?

Your resting metabolic rate (RMR) is the number of calories (energy) you burn to maintain essential bodily functions, such as breathing, keeping your heart beating, and maintaining your body heat.

RMR is by far the most significant component of total daily energy expenditure 2 unless you happen to be a professional Ironman triathlete or Tour de France cyclist.

To summarize RMR, it's the number of calories you burn if you were to do absolutely nothing all day except sleep or lay in bed and not move.

RMR may be what most people consider to be their “metabolism.”

What Is The Thermic Effect Of Food?

The thermic effect of food (TEF) is the amount of energy (calories) required to eat, digest, absorb, and store food.

According to research, TEF accounts for nearly ~10% of our total daily energy expenditure (TDEE). 3

You can look at TEF as the number of calories it takes to digest the food you eat. Certain macronutrients, more specifically protein, require more energy to digest than carbohydrates or fat.

So one can argue that eating a more significant proportion of calories coming from protein would be an easy tool to increase this segment of your TDEE.

What Is Physical Activity?

Physical activity (PA) is the most self-explanatory of the four pieces of your TDEE.

Physical activity is any voluntary exercise you engage in. Lifting weights, going for a run, or playing a sport all fall under physical activity?

What Is Non-Exercise Activity Thermogenesis (NEAT)?

NEAT is all the activity you engage in daily that ISN'T physical exercise. NEAT includes activities like walking, tapping your feet when you sit, doing laundry, and even sex (that is unless you purposely engage in it for exercise).

Research shows that NEAT may vary by up to ~2,000 calories per day in individuals that are of the same height and weight. 4

To put that into perspective, a pound of fat has ~3,500 calories, so a little more than a pound of fat over two days.

This may explain the reason why you see someone who starts at the same height and/or weight as you lose weight slower or more rapidly than yourself.

They simply move around more throughout the day.

NEAT INTERMITTENT FASTING AND METABOLISM

NEAT also plays a significant factor in why you may believe that your metabolism is slowing down. Naturally, as you diet, your body decreases its spontaneous activity, thus reducing its average daily energy expenditure. 5

Research also shows that this adaptation to reduced NEAT can sometimes continue, even after we've stopped dieting, thus resulting in weight regain after you've returned to regular eating. 6

NEAT may ultimately be the culprit when one feels their metabolism has “slowed down” or their body is in “starvation mode.”

A good counterbalance may be to use a step tracker or other smart device to ensure a minimum daily movement or step count.

Intermittent Fasting Metabolism Study

There have been numerous studies on Intermittent Fasting (IF) or Time-Restricted Eating (TRE), as cited by the scientific literature, in both sedentary and athletic populations.

In the context of weight and fat loss, IF's primary mechanism of action is its ability to control calorie intake. Meaning, by restricting your eating window, people seem to eat less food overall naturally.

In one study, participants were told to delay their normal breakfast time by 1.5 hours and move their normal dinner times up by 1.5 hours. This simple shift in eating times, and with no other instructions, resulted in less food eaten, and thus weight loss. 7

Another study had individuals eat within a 10-12 hour eating window of their choosing.

Again, no other instructions were given (they could eat whatever and whenever they wanted as long as it was in a 10-12 hour window). 8

Can you guess what happened? Subjects spontaneously ate less, and thus lost weight.

Just to reiterate, these subjects were also not following a ketogenic diet.

Wondering if you can do IF without keto?

In terms of metabolism, this study following individuals using a 16/8 feeding window found a slight reduction in T3, but no changes in thyroid-stimulating hormone (TSH) or resting energy expenditure.

It would seem as though no studies can show any meaningful impact when it comes to slowing the metabolism.

Does Extended Fasting Slow Metabolism?

Most people who do intermittent fasting (IF) usually engage in a 16/8 fast to feast eating protocol. However, some specific individuals like to take things a little further and do much-extended fasts.

We're talking about 24, 48, 72, and longer fasts.

But do extended fasts slow metabolism? Extended fasts do not seem to slow metabolism, but quite the opposite. Resting energy expenditure increases during the early stages of extended fasting. 9

You read that correctly.

Extended fasting, at least during the first 72 – 84 hours, research has shown an INCREASE in metabolism and plasma norepinephrine.

Norepinephrine plays a central role in the regulation of energy metabolism, which may explain the increase we see during short periods of starvation.

This might be a way of the body, kicking us into high-gear to find food. Our ancestral biology is telling us to go and hunt some food before we die of starvation.

What Are The Drawbacks Of Intermittent Fasting

Now that we've established intermittent fasting, even extended fasting, doesn't seem to slow down the metabolism, what are the potential downsides of IF?

Decreased Muscle Protein Synthesis (MPS)

If muscle gain is of any concern, intermittent fasting may not be the most “optimal” protocol. Notice the word optimal; I didn't say you couldn't gain muscle.

While you can gain muscle by eating all your meals in a small eating window, you won't be doing your body justice in terms of building muscle.

Muscle protein synthesis (MPS) is the process of building muscle mass.

Think of muscle protein synthesis as money going into your bank account, and muscle protein breakdown (MPB) as debits drawn from your bank account.

Building muscle requires more money (MPS) going into the account, then money drawn (MPB) from the account.

To effectively stimulate MPS to near maximal levels requires ~20 grams of protein, while going up to 40g may result in a ~10% increase.

Now, the problem with intermittent fasting is the limited amount of times we can stimulate this process. MPS, once stimulated, experiences a refractory period where the muscle can no longer respond to incoming amino acids, referred to as the muscle full effect. 10 11

During this period of ~ 3 hours, MPS can no longer be stimulated.

You can see how IF, and consuming only one or two meals would not be ideal for stimulating this process. In fact, it's entirely possible to lose muscle on keto if you're not careful.

Food focus

Some people decide to give intermittent fasting a try but like to eat small meals throughout the day.

You may have read that intermittent fasting is the holy grail for weight loss. Still, the reality is both IF and continuous energy restriction (smaller meals throughout the day) will generally provide the same results. 12

Given you keep the calories the same.

If IF stresses you out, causes you to continually watch the clock like a hawk waiting for your eating window, maybe it's time to try a different approach. I'd argue to say you're doing more harm than good as there is very little to no benefit when it comes to IF and weight loss.

However, if you enjoy condensing your eating window, enjoy larger meals less frequently, and eating in a time-restricted fashion allows you to adhere to your diet much better, then keep doing it.

May lead to binge eating

There were times that IF opened the door to overeating, at least for myself. I would go the whole day without eating, so by the time it was time to eat, I was RAVENOUS.

Intermittent fasting led to my appetite getting out of control… sometimes.

If this sounds like you, maybe IF isn't for you either.

This is the case for many people who utilize programs like Speed Keto which adopts the one meal a day (OMAD) schedule of eating.

How To Keep Metabolism High While Fasting

While some metabolism downregulation is expected due to weight loss, not so much intermittent fasting, there are things we have within our power to change.

There are a multitude of reasons why you may not be losing weight or hit a plateau. Want to find out more? Check out my article on the 11 Reasons Why You're Not Losing Weight On Keto.

NEAT

As mentioned earlier, a significant proportion of our daily calories that IS in your control comes from non-exercise activity thermogenesis (NEAT).

People of the same body weight and height can vary by as much as 2,000 calories per day, which is nothing to scoff at.

NEAT is one of the biggest culprits, if not THEE biggest culprit when it comes to hitting a stall or plateau in your weight loss efforts.

The best way to keep your metabolism high while fasting is simply to MOVE MORE!

I'm a big fan of keeping a daily step count, but if that causes anxiety for you, that may not be ideal for you.

This is the part where I say, every little thing adds up, and that's because it does.

The best way to increase your NEAT is by building in small habits a little at a time.

Park further when you go to the store or the office
Take the stairs instead of the elevator
Walk (when you can) instead of driving
Take your dog out for a walk
Do some chores you've been putting off
Pick up the hobby you've always wanted to

The simple act of staying active throughout the day will burn more calories than hopping on that treadmill for 20-30 minutes, and more enjoyable at that.

Pedometer intermittent fasting metabolism slowdown

Eat more protein

Another tip is to increase your protein intake.

You're almost always better eating TOO MUCH protein than not enough protein.

Not only is protein considered the most satiating macronutrient 13, it also burns the most calories through digestion (thermic effect of food).

Just to illustrate the different macronutrients and their effect on metabolic rate:

Protein ~15-30%
Carbohydrates ~5-10%
Fats 0-3%

And while you won't be consuming extremely high protein intakes, chronic consumption of a diet high protein has proven to be relatively safe with no harmful effects on any measure of health. 14

Of course, if you have a pre-existing disease or impaired kidney function, this would not be ideal.

How much protein should you eat? A good rule of thumb is to eat 1 gram per pound of desired body weight. Meaning, If you weight 200 pounds but wish to drop down to 180, then you would consume 180 grams of protein per day.

Ideally, you would eat 1 gram per pound of lean body mass per day (lean body mass is your total weight – your fat weight).

Include resistance training

Aside from the numerous health benefits resistance training provides, having more muscle equates to a faster metabolism.

During periods of calorie restriction (dieting for weight loss), weight from both fat AND muscle tissue is lost.

Our goal during periods of weight loss should be not only to lose weight, but ONLY lose fat.

This means we want to spare all of the muscle we currently have or possibly increase it.

If you've never lifted weights before, you're missing out on a prime opportunity to lose both fat AND gain muscle, known as body recomposition.

Beginners who undertake weight training have a high probability of accomplishing both tasks in the short term, but most end up shortchanging themselves by trying to diet without exercising.

Additionally, including any type of exercise is often one of the predictors, those who successfully manage to KEEP the weight off employ.

It's said that 6 out of every 7 people who are overweight are able to lose weight at some point during their lifetime. Up to ~95 of these people end up regaining the weight.

What's more alarming is that one to two-thirds of these same individuals end up heavier than when they started.

Intermittent Fasting For Weight Loss

The number one reason that intermittent fasting has been shown to aid in weight loss is by causing individuals to eat less over time.

There is no inherent benefit to intermittent fasting over spreading out your meals throughout the day unless it helps you maintain a caloric deficit.

What Supplements Help Increase Metabolism

Very few supplements on the market are worth taking, at least when it comes to fat loss.

Wondering if you can take fat burners on keto and/or IF? The answer is yes, but let's hold onto that thought for a moment.

Most supplements, especially ones claiming to burn fat, are useless.

The real mechanism most supplements work is to help lighten your wallet.

Just take a look at my shark tank keto diet pill review, which is scamming hundreds of thousands of people.

And that's the truth.

Want to know what the most effective supplements are?

In short, the only ones that are likely to be useful and worth considering are:

Caffeine
ECGC (Green Tea Extract)
Yohimbine HCL (If you're already lean)

You'll have to read the other articles if you're interested in more information about these specific compounds and how they may aid in fat loss.

If you're looking for fat burners specifically, then check out this article: Can I Take Fat Burners On Keto?

If you want to know more about any effective supplement in general, then check out this article: The Best Keto Supplements Of 2020.

The Takeaway

Research has shown that intermittent fasting does not have a detrimental effect on metabolism. In fact, short periods of extended fasting have shown that metabolism increases.

However, metabolism does downregulate slightly through other mechanisms during periods of weight loss.

First, you're carrying a lighter body, so you burn fewer calories doing the same activities.

Secondly, your spontaneous movements (NEAT) generally goes down.

Lastly, to combat these adaptations, it's suggested that you remain active throughout the day and engage in resistance training as muscle is more metabolically active than fat.

Intermittent Fasting Without Keto? [A Better Approach]

When people hear about or adopt a ketogenic diet, they begin to dig around for ways to optimize their results or speed things along. Eventually, I want to say the majority of people who follow a ketogenic diet learn about intermittent fasting.

Intermittent fasting or IF may be used without the use of a keto diet. Intermittent fasting is a schedule of when to eat versus a ketogenic diet, which is more of what to eat or not eat. The two may be used together or entirely separate from one another with great success.

However, for one reason or another, you may find yourself wanting to transition off of a ketogenic diet, but still wanting to implement the intermittent fasting (IF).

In this article, I'll go over if you can still lose weight without keto, different intermittent fasting protocols, why IF may not be all that it's cracked up to be, and possibly a better alternative to IF.

Can You Lose Weight Intermittent Fasting Without Keto?

I get asked this question quite often from individuals who found keto and IF but want to move to a diet with more moderate carbohydrates.

Can you lose weight intermittent fasting without keto?

And the answer is… of course, you can.

You can lose weight without keto AND without intermittent fasting. You may have had trouble losing weight previously, and keto and/or IF seemed like the holy grail, but it was just another means to an end.

As the saying goes, there's more than one way to skin a cat.

You can look at both keto and intermittent fasting as tools you can implement when the time is right, but don't confuse that with them being THEE only tools you can use for weight loss, weight maintenance, or even weight gain if that's what you're after.

How To Lose Weight Without Keto

You may have been led to believe that eating VERY low-carb or keto was the only way you'd be able to lose weight. I get it, I was in your shoes, and I too believed that at one point, but I assure you that's not the case.

While lowering carbohydrates or following a ketogenic diet may help many individuals, as it did me, and possibly you, it's not the be-all-end-all.

Keto can be great for many reasons:

While keto may be great at helping you lose weight, and some people find it a sustainable lifestyle, there are just as many who do not want to stay keto forever.

I get it.

As much as you've been led to believe that carbohydrates are evil and calories don't matter, neither one is true.

Weight loss still comes down to the fundamental principle of calories in vs. calories out. (CICO) The hard part about calories in vs. calories out is that those numbers are always changing, which makes it hard to calculate accurately.

ENERGY DEFICIT VS ENERGY BALANCE IF WITHOUT KETO — While energy in is easier to calculate, energy out is much more dynamic.

Plus, most people don't want to have to count calories.

And you don't have to.

So I Have To Count Calories To Lose Weight?

Counting calories IS NOT required to lose weight, and you definitely can lose weight without counting calories.

But don't confuse not having to count calories with being the same as calories don't count.

There may be a benefit for specific individuals to count calories, and the research also shows a trend towards more weight loss and maintenance of weight loss with those who do track calories, but that’s a whole other discussion in and of itself.34

Which leads me to my next point, the adage of eat less move more IS also true, but we can all agree it is not helpful advice.

The reason you may have lost weight on keto, with or without exercise, and possibly without counting calories, is because ketogenic diets are known for suppressing appetite5, which causes you to eat less overall.

No matter how you put it, every diet that causes weight loss works through the same fundamental principle, it causes you to eat less.

Therefore, the only way to lose weight is to eat in a manner that allows you to remain in a caloric deficit consistently.

Whether that's keto or not.

How Intermittent Fasting Helps You Lose Weight

First, let's define what intermittent fasting is.

Intermittent fasting is an umbrella term to describe various meal timing schedules that involve periods of fasting (not eating or reduced calorie intake) with periods of non-fasting (eating).

What most people refer to as intermittent fasting should really be referred to as time-restricted eating (TRE). Intermittent fasting can encompass periods of dieting (calorie restriction), regardless of daily timing, with periods of not dieting.

On the other hand, time-restricted eating (TRE) is restricting your eating window to a particular time or hours in the day.

Makes sense, right? Time-restricted eating means restricting the time that you eat.

Intermittent fasting means times of not eating (fasting) OR eating less (calorie restriction) with times of eating (not fasting) or not dieting (not calorie-restricted).

I'm assuming most people will be eating within an 8-hour eating window or less, which I will intermittently (see what I did there) refer to as both intermittent fasting (IF) and time-restricted eating (TRE).

So how does time-restricted eating help you lose weight?

For the most part, time-restricted eating helps people lose weight through the same fundamental I spoke of earlier. TRE causes weight loss by helping you achieve a caloric deficit.

Calories in vs. Calories out

Had you eaten the same amount of calories you did during your 8-hour eating window, but spread throughout the day, there would be no statistically meaningful difference in weight loss. 6

Since that cat is out of the bag, how does IF or TRE help you lose weight?

For one reason or another, condensing the eating window works for some people.

Certain individuals find it easier to eat bigger meals less frequently, while some people prefer smaller meals, but more frequent.

In one study, participants were only instructed to delay their breakfast time by 1.5 hours and eat dinner 1.5 hours earlier, thus shortening their eating window by 3 hours. No other rules were given about what to eat or how much to eat.

A simple change in the time frame of when these people ate was enough to cause them to consume significantly fewer calories and, as a result, lose weight. 7

In another intervention, participants ate within an 8-hour feeding window, but at whatever time of the day they preferred. Again, no other rules were given, and over 16 weeks, participants lost more than ~6.5 lbs. 8

Maybe you're not hungry in the morning, that's great, skip breakfast and have bigger meals later in the day.

However, if skipping breakfast causes you more stress because you're starving when you wake up, then eat when you wake up!

There is no inherent benefit for weight loss in terms of TRE unless that benefit is allowing you to adhere to your diet better and eat less overall, which is the main benefit for people.

Many individuals like to be social in the evening or have bigger dinners, and many people want to go to bed on a full stomach rather than semi-hungry. IF allows these individuals to stay under their calories for the day, with makes it applicable to them in losing weight.

As you may begin to notice, the main benefit of intermittent fasting on weight loss is the ability to cause people to eat less by restricting the eating window.

Therefore, my advice would be to eat in a way that you enjoy and that you can adhere to.

In the end, the most critical overlying factor will be the total amount of food (calories) you eat, not the times that you eat it.

What Is Better Than Intermittent Fasting

If intermittent fasting, aka time-restricted dieting, is no better than intermittent fasting, what do I recommend?

Everyone's different has different needs and can tolerate different modalities. Without knowing YOU as a person and your history/background, it's almost impossible for me to tell you what to do.

BUT, here's what I do recommend for most people.

Instead of intermittent fasting, or in addition to, if you enjoy that style of eating, I recommend intermittent dieting (or intermittent fasting as per the scientific definition).

That means, alternate periods of dieting and actively trying to lose weight with periods of non-dieting and maintaining your weight, aka taking a diet break.

Now, when I say diet break, this doesn't mean a free for all. You should be eating a little more food, just enough to maintain your weight plus or minus a pound.

This period of increased food acts to help to give you a break both psychologically, but physically as well.

A study, known as the MATADOR study, took two groups of people who dieted a total of 16 weeks. The first group of people dieting for 16 straight weeks, the second group of people also dieted for 16 weeks BUT completed the 16-weeks in 8 x 2-week blocks.

Meaning, the second group dieted for two weeks, followed by two weeks of maintaining weight (more food).

In the group that intermittently took breaks every two weeks, greater weight and fat loss was achieved. Additionally, the same group also had a higher success rate of maintaining weight loss after the intervention. 9

While a break every two weeks isn't necessary, it's essential to realize that now and then, we have to take a break both mentally and physically from dieting.

It would seem as though taking periodic breaks also allows us to tackle the next few weeks energized and refreshed, thus providing a better outcome.

Besides, it's much easier to stay the course when mentally you will know there's a break every few weeks versus every few months, or *gasp* not at all.

Whether it takes you a month or six months to lose the weight, will it matter when you look back five years from now? I bet it won't. You'll be glad that you lost the weight in the first place, and managed to keep the weight off through smart decisions and building up healthy habits.

Dieting is a stress, and we can't be continuously stressed without eventually breaking.

Here is a generalized guideline of how often to take a break while dieting.

So Can You IF Without Keto?

You can implement intermittent fasting with keto or ANY other diet you choose to follow.

However, keto may allow some people to adhere to an intermittent fasting protocol easier due to the appetite-suppressing effects of a ketogenic diet, so you would have to try for yourself.

Intermittent fasting or time-restricted eating is just a method of eating that is convenient for some individuals or allows them to adhere to a caloric deficit, regardless of foods eaten.

A caloric deficit is the overlying determining factor whether you lose weight or not despite what other keto gurus may lead you to believe.

The Hidden Truth About Keto And Intermittent Fasting

Keto and intermittent fasting are all the rage these days. I mean, you usually don't hear about one without eventually hearing about the other.

But is there any benefit in combining the two for the purposes of weight loss?

There may be other benefits, weight loss aside, to combine keto and intermittent fasting, but is there any inherent fat loss benefit?

Can you combine keto and intermittent fasting?

Of course, you can combine keto and intermittent fasting, they go together like peanut butter and jelly. However, know that one also doesn’t require the other, and most people find it easier to implement intermittent fasting on a ketogenic based diet than a carb based one.

But we’ll get to that.

I am going to assume you know what keto is already, so we won't be doing an entire keto 101 in this article. If not, give my ketogenic diet guide a read through, but in general…

What is Keto?

Most websites and people would have you believe that keto is a “diet” or a certain type of “food,” and they would be right… to an extent.

In reality, ketosis is a metabolic state where your body essentially runs on ketones (fat) instead of glucose (sugar).

When you limit or eliminate your carbohydrates, your body has no choice but to break down the fat from the food you eat AND the fat on your body to create energy for your body and your brain.

It’s kind of like when you have a hankering for cereal and you run out of milk… so what do you do? You have to use water instead.

Basically, your body ends up running out of sugar and it’s forced to use what’s left… your fat stores.

Blasphemy, I know… but don’t pretend like you’ve never done that in your lifetime. Besides, you’re on a keto diet now so you ain’t about that cereal life anymore.

What is intermittent fasting?

In the most general of cases, intermittent fasting is combining periods of eating with periods without eating. Therefore, Intermittent fasting is not a diet per se; instead it's a pattern or schedule of eating.

When I say intermittent fasting is not a diet it's because IF doesn't change what you eat, it changes when you eat. That said, weight loss is the most common reason people give intermittent fasting a shot.

Examples of different intermittent fasting schedules

There is no one way to implement intermittent fasting, so I've outlined a few popular methods down below.

DAILY

One of the most popular ways to implement intermittent fasting is a daily fast of 16 hours followed by an 8-hour eating window. It really doesn't matter when you start your eight-hour eating window, but most people tend to start it around noon or early afternoon.

The reason most people have their feeding window in the afternoon is that, in general, people find it easier to skip breakfast, rather than dinner. Besides, if you went 16 hours without food and you can spend the first eight hours or so asleep… you would probably find it easier too.

On top of that, allowing for dinner makes it more convenient from a schedule standpoint. You can eat with your family or go out during social events and not be the only person in the room not eating

… because you're fasting.

Personally, I prefer this schedule because I like to go to bed on a full stomach.

As far as daily scheduled intermittent fasts go, people start to either shorten the eating window or even lengthen it slightly. Some might even go as far as to take all the calories for the day and eat it in one big meal.10

Remember, there are no hard or fast rules… if you find yourself slightly hungry before your “eating window,” then go ahead and eat. Vice versa, if you aren’t hungry and want to remain fasted, then remain fasted.

I’ve used this method of intermittent fasting on and off for over 10 years now, but I’m not fanatic about it to the point that it runs my day. If my friends or family go out to breakfast or some friends invite me over to watch the game and nosh on some wings, guess what? I don’t care that it’s outside of my “feeding window.”

WEEKLY

This schedule of intermittent fasting is generally a good way to introduce yourself to intermittent fasting. You pick one day out of the week and simply don’t eat.

It’s really that easy.

If going an entire day from the time you wake up to the time you go to bed seems daunting, try fasting after dinner (6pm for example) from the previous night until dinner (6pm) the following night. In the end, you still technically will have fasted for at least 24 hours and ends up like the (OMAD) one meal a day mentioned in the daily section.

Perhaps one of the biggest benefits of doing a weekly fast is getting over that mental barrier of fasting in the first place. If you’ve never fasted before, this may seem like a daunting task, but successfully completing your first 24-hour fast can help you realize it isn’t as frightening as your head makes it out to be.

ALTERNATE DAY

Alternate day fasting may be the most challenging schedule from a mental standpoint since you will be going without food for about ~36-hours at a time.

For example, you would eat normally on Monday until dinner, then begin your fast until Wednesday morning. Then, you would repeat the process by eating normally Wednesday and beginning your fast Wednesday after dinner and not eating until Friday morning.

Hypothetically, this would yield the most benefits since you are going long periods without food more frequently. Alternate day fasting would likely yield the most weight loss as well since you are going longer periods without food and more likely to have greater caloric deficit.

Assuming you don’t eat like an asshole on the days you do eat.

As I said, myself and many other much prefer the 18-hour daily fasts since it’s typically much easier to simply skip breakfast most days. If you do choose to combine keto and intermittent fasting then experiment with the different schedules and see how you feel.

Intermittent fasting. Not to be confused with intermittent dieting or intermittent energy restriction.

In short, intermittent dieting or intermittent energy restriction is NOT the same as intermittent fasting. Intermittent dieting is when you include brief periods, typically days or weeks, where you intentionally aim to MAINTAIN weight between periods of weight loss dieting.

These may be commonly referred to as refeeds or diet breaks.

But we’ll cover that in another article on why it may benefit you in the long run when it comes to losing weight.

Keto and intermittent fasting – They go to gather like peanut butter and jelly.

Keto and intermittent fasting for weight loss.

You may want to combine keto with intermittent fasting to accelerate your weight loss, but probably not for reasons you may have been led to believe. Research suggest that an 8 hour feeding window produces mild caloric restriction and weight loss, without calorie counting. 2

In layman's terms, it caused people to eat less overall. I mean, it makes sense right? You are essentially giving yourself less time to eat.

Which leads me to my second point…

Calories still matter. On a keto diet, when intermittent fasting, or combining keto and intermittent fasting… calories still matter. BUT, as the study suggested, intermittent fasting MAY be a way for you to eat less without really having to count calories.

AGAIN, as long as you don’t eat like an asshole during your 8-hour or however long eating window.

Personally, I can still easily manage to overeat in such a short time frame. However, I am an endless pit, and most normal people will find it difficult to cram too much food in such a short period of time

Thus making it a viable option if you can eat “sensibly” during your feeding window.

Reasons why keto and intermittent fasting work well together.

People are more satiated on a ketogenic diet

People tend to eat fewer calories on a ketogenic diet… SPONTANEOUSLY, as in without trying to restrict calories.3 This is important to note since hunger is a primary reasons people fall off most weight loss diets.

There is no conclusive reason to as why this occurs, but one theory is that ketone bodies (our primary fuel source on a ketogenic diet) may suppress appetite.4Sumithran et al., 2013

Pair intermittent fasting with keto and you have the benefit of:

Less or no hunger during your fasting window
Increased chance of weight loss without counting calories

On the flip side…

IF may ease your transition to a ketogenic diet

Intermittent fasting may help transition your body into a state of ketosis over doing a ketogenic diet alone.

During your fasting window, insulin and glycogen decrease, 5 naturally leading your body to start burning fat for fuel. This is one of the driving reasons people even on a carbohydrate-based diet implement intermittent fasting.

I also mention in my article How long does it take to get into ketosis? that intermittent fasting or just plain fasting will help speed up your transition into ketosis.

Intermittent fasting and Keto – Weight loss aside, here are some benefits.

You can type in intermittent fasting in google or your favorite social media platform and you’ll hear things like “autophagy” and IF made me poop rainbows and dream about unicorns.

Don’t get me wrong, you do you… and if you love doing it and you see results, then, by all means, keep doing it!

But if there comes a point where you’re stressing out about if you should eat, what can you eat, can you drink this, but I want this for breakfast, then you’re just better off not worrying about it. In the end, there’re bigger things you can focus on instead of watching the clock for when you can eat.

Up until recently, many of the intermittent fasting benefits you’ve heard (or haven’t heard) were weak at best. Many of the studies which reported benefits could easily be attributed to the weight loss participants experienced versus the actual intermittent fasting.

However, there are recent findings that may suggest intermittent fasting (also known as time-restricted feeding) does have benefits even WITHOUT weight loss.6Sutton et al., 2018

The only caveat, the feeding window would be more in line with your circadian rhythm. Meaning, you would eat according to your internal clock.

To simplify, you would have your FASTING window in the evening. Basically, eat during the first 8 hours of the day, generally when the suns out.

Which is probably the opposite of what most people are doing.

This schedule of eating is referred to as Early time-restricted feeding (eTRF) and has been shown to:

Increase insulin sensitivity
Lower blood pressure and oxidative stress
Lower the desire to eat in the evening (so maybe skipping dinner or making it super early might not be as bad as you might think)
Improve health EVEN in the absence of weight loss

The only problem with this is people are social beings and we eat for reasons beyond hunger, which is a problem it and of itself. It’s also much easier to fast during the day because people are typically busy at work and can focus on other things besides food.

It’s also just my humble opinion, but I think most of the benefits of eTRF stem from the fact that you’re eating earlier in the day versus the actual time restriction.

A large majority of the population suffer from circadian arrhythmia. 7 In today’s society, we tend to stay out (or just up) late, drink alcohol, expose our eyes to artificial light in the evenings, etc. Eating earlier may be a way to re-align our circadian rhythms.

If eTRF sounds like something you want to give a shot, you have my blessing.

Not that you needed it.

That said, intermittent fasting for me makes my day simpler.

Intermittent fasting allows me to eat one less meal, which also means cooking one less meal and therefore stressing about one less meal. When I wake up, I don’t have to worry about breakfast, but can get to other more important tasks at hand.

Like coffee. 😉

I also like to eat more substantial meals.

I’m the type of person that likes to eat HUGE meals and go to bed on a full stomach, whether that’s good or bad is a whole other topic of discussion we’ll save for another day. I’m not advocating you eat huge meals or go to bed on a full stomach, it’s just my preference and what works to keep me adherent to a caloric deficit.

… and remember, in the end a caloric deficit IS required to lose weight. Intermittent fasting can be used as a tool to achieve a caloric deficit whether you want to count calories or not.

Who should try an intermittent fasting Keto approach?

The jury is still out on whether there is an INCREASE in fat loss by using intermittent fasting versus traditional caloric restriction. A systematic review 8 was published in December of 20189Cioffi et al., 2018 that found no difference.

Both intermittent and continuous energy restriction achieved a comparable effect in promoting weight-loss and metabolic improvements.

– Cioffi et al., 2018

So the jury is still out on whether or not intermittent fasting is MORE effective than if you were to spread your meals throughout the day. This is also assuming you ate the same amount in the ~8-hour window or ~16-hour window.

That said, I would try intermittent fasting if:

You enjoy less frequent but LARGER meals
You don’t necessarily find yourself that hungry in the mornings (or evenings)
It allows you to adhere to your diet over the long term
You simply want to experiment

The bottom line on Keto and intermittent fasting

You need to be up front and honest with yourself if choosing to utilize intermittent fasting because context is everything. Don’t say that you’re doing it for health, autophagy, [insert reason you give your friends], when in reality it's that you think it burns more fat.

I do believe there are health benefits to intermittent fasting and fasting in general, but I’d be skeptical to assume there is any inherent fat loss benefit to restricting your eating window.

At the end of the day, intermittent fasting isn't magic when it comes to weight loss. If combining keto and intermittent fasting works for you and fits your lifestyle, then by all means…

Implement it.

However, if trying to implement keto and intermittent fasting makes everything much harder, stresses you out, or makes adhering to your diet more difficult, then it's not a worthwhile trade-off.

Keto and intermittent fasting F.A.Q.

Can you do keto and intermittent fasting together?

You can definitely do keto and intermittent fasting together. In fact, keto will make intermittent fasting much easier to adhere to due to its satiating nature.

Do I have to eat keto while intermittent fasting?

No, you do not have to eat keto while intermittent fasting.

Does intermittent fasting cause ketosis?

Intermittent doesn't directly cause someone to go into ketosis. That said, During the tail end of longer fasts it is highly likely that the body is beginning to produce ketones.

Do you fast on a keto diet?

Fasting is up to you whether or not you want to include it for the health benefits or diet adherence.

Is Intermittent Fasting better than Keto?

Intermittent fasting and keto are two entirely separate things. Intermittent fasting is a schedule of when to eat. Keto is a metabolic state achieved by what you eat.

Can I drink coffee during intermittent fasting?

Yes, you can drink coffee or any non caloric beverage during your fasting window.

How often should you intermittent fast on keto?

How often you intermittent fast on keto is dependent on your preference.

How much weight can you lose with intermittent fasting?

How much weight you can lose while intermittent fasting is dependent on your total caloric deficit. The recommendation is to lose between 0.5 – 1.5% of your total bodyweight per week. The more fat you have to lose the more you can expect to lose without risk of losing lean body mass.

How long is intermittent fasting?

The duration in which you intermittent fast is dependent on the method you choose to implement whether that's daily, weekly, or alternate day fasting.

How long does it take to get into ketosis while fasting?

From my experience, it typically takes between 24-48 hours to get into ketosis if completely fasting.

How long does it take for your body to go into ketosis?

How long it tales your body to go into ketosis depends on your previous diet, your activity levels, and what you are currently eating.

Can you go into ketosis in 24 hours?

Yes, it is possible to go into ketosis within 24 hours by fasting. While not always the case, you can typically start seeing low levels of ketones between 24 – 36 hours after starting a fast.

What is a fat fast?

People commonly refer to a fat fast as eating a diet composed of 80 – 90% fat for 4-5 days and limited to 1000-1200 calories broken down in 3-4 meals.