Occasional 24 Hour Fast

Start with a 12-hour fasting window, then gradually work your way up to 14 hours, then 16 hours. Drink black coffee, tea, carbonated water, and plain water to fill you up during your fasting. The rationale behind a weekly 24-hour fast is that consuming fewer calories will lead to weight loss. Fasting for up to 24 hours can lead to a metabolic shift that causes your body to use fat as an.

1. Occasional 24 Hour Fast
2. Occasional 24 Hour Fasting

I’ve had amazing results over the last 2 years or so using a combination of:

• Heavy weightlifting just 3 times per week
• And intermittent fasting

I’ve built strength and muscle, along with shedding at least 15 or more pounds of body fat.

But right now, as I write this, I’m about 4 months into a bulk.

Using intermittent fasting on a bulk is a great way to stay lean and moderate your calories, but no matter how you slice it, there’s always a little bit of fat gain when building muscle.

And I’m a little fluffier right now than I’d like to be!

I wanted to know if doing a 24 hour fast would help me lean out and burn some fat while still continuing on my path to gaining strength and muscle — (in other words, a 24 hour fast while bulking!).

So I decided to try a 24 hour fast and write down my results before and after (plus pictures).

But first, I needed to know a lot more about long, extended fasts and how they affect your body.

(By the way, did you know you can use a simple breath sensor like this one to detect if your body is in ketosis, aka fat-burning mode, during a fast?

What actually is fasting? (24-hour fast definition)

There’s a lot of confusion out there about what’s actually considered “fasting.”

Occasional 24 Hour Fast

So let’s clear that up right now.

Fasting is any prolonged period of time over around 8 hours without food.

So, technically, just having dinner and going to sleep (usually) constitutes a fast!

Around this 8 hour mark, the last food and calories you ate have been digested and processed.

(Many of those calories, and especially carbohydrates, are turned into glucose and stored in the liver and muscles to use as energy.)

Somewhere around 8-12 hours without any food or calories, your body will run out of these glucose reserves.

At this point, your body begins to tap into other sources, primarily body fat, for new energy.

During a 24 hour fast, then, that means your body’s running on mostly burned body fat for somewhere between 12-16 hours before you eat again and provide more material for glucose production.

In much longer fasts (beyond 72 hours without food), your body may enter starvation mode and begin slowing down its metabolic rate (how fast it uses energy) and tapping into muscle tissue for energy.

(That’s not a good thing!)

Most research indicates that shorter fasts like intermittent fasting (16, 18, or 20 hours) or 24-hour fasts are muscle sparing, meaning you are very unlikely to lose lean mass during a fast.

Your body far prefers to burn glucose, first, then body fat for energy.

What are the benefits of a 24 hour fast? (Or why I decided to do it)

First, let’s run through the science-backed benefits of fasting (whether that’s a shorter 16-hour fast or a longer 24-hour one.)

According to Healthline, fasting can:

• Reduce inflammation
• Reduce insulin resistance (keeps blood sugar levels steady)
• Improve blood pressure, cholesterol & other health markers
• Boost metabolism & how many calories you burn
• Provide a surge of growth hormone
• Improve appetite regulation
• Lead to a loss of water retention & water weight

There are some cool side bonuses of fasting, like the fact that it forces you to hydrate thoroughly (zero-calorie liquids are all you can have!).

It also helps you distinguish between actual hunger (lack of nutrients) and boredom or psychological hunger, which could lead to a healthier relationship with food.

Then there are the anecdotal benefits of fasting like:

• It can help improve your skin and clear acne
• It’ll improve your energy and focus
• Some people swear fasting fights disease

For my purpose, the benefit of fasting that I’m most interested in is fat loss and fat burning.

Again, I’m going into this from the perspective of someone who wants to continue gaining strength and muscle while staying lean.

I want to test out whether it’s possible to burn off body fat during a fast and keep it off when you resume eating in a calorie surplus the next day.

(If it clears my skin and gives me more energy, that’s just a bonus! Losing a little water weight sounds pretty good, too.)

You can tell your body is converting fat into energy while fasting by using a handheld sensor like this one that detects acetones in your breath.

What are the risks of a 24 hour fast?

There are definitely drawbacks of doing a long fast, like, oh, I dunno, the fact that it sounds hard!

After all, eating is fun. Not eating for a whole day sounds kind of not fun.

But in general, most sources that I’ve read agree that 24-hour fasts are completely safe.

The exception would be if you have an existing medical condition related to blood sugar, blood pressure, or cholesterol, all of which can be altered by dieting.

You should consult with your doctor before doing a 24 hour fast if that’s the case, and especially if you live with a condition like diabetes.

For most of us, though, our bodies are completely capable of burning through glucose and then a little bit of body fat for one measly day.

Occasional 24 Hour Fasting

As long as you stay well-hydrated and eat nutritious foods before and after the fast, there’s very little concern to be had.

Will your body go into “starvation mode” during a 24 hour fast?

It’s highly unlikely.

Starvation mode is (mostly) a myth.

The idea is that, during fasting or dieting, your metabolism slows down so much in an effort to survive (and not starve to death) that it becomes impossible to lose more fat.

Sounds… reasonable?

This can (maybe, sort of) happen, but it’s not at all caused by eating a few hundred calories less per day or doing a short fast.

Starvation mode, in reality, is what happens when you’re actually starving to death and have been deprived of nutrients to a severe degree.

That’s when your body starts eating away at its own muscle tissue in order to survive.

This would most likely take your body several days (or more) without any food at all, and it wouldn’t happen until you chewed through a substantial amount of body fat first.

This, ACTUAL starvation mode, is really dangerous for obvious reasons, including the fact that muscle breakdown of this level can release toxic proteins into your system.

There’s plenty of evidence out there of people who do regular two or three-day fasts without any negative health issues, so you’re definitely not going to starve doing a short, one-day fast.

Preparing for the 24-hour fast and the “rules”

Alright.

It’s time for me to get ready to do a full one-day fast, and there are a couple of things to think through.

Namely, what am I allowed to have during my 24-hour fast?

Based on some research and my own thoughts, I’ll be able to drink:

• Black coffee
• Naturally flavored zero-calorie sparkling water
• Water (duh)
• Green tea

I’m going to try like hell to avoid artificially sweetened drinks like diet soda. They can be a nice treat during a fast but sometimes they can make your hunger cravings worse when you’re done.

The other thing I need to prepare is my post-fast meal.

I’m going to start fasting after dinner on Day 1 and resume eating at dinner on Day 2.

Since I’m trying to hit my normal bulking calories (or at least come close), I have to choose Day 2 dinner really carefully. It’ll be hard to get enough calories in that day in such a condensed amount of time.

Of course, I could cram in lots of junk calories easily, but to properly hit my macros I really need a dinner that will be:

• Calorie dense
• Protein heavy
• Have some whole grains & veggies

I’m thinking of cooking up some big old chicken breasts for a massive bomb of protein, and topping it off with some pasta (heavy on the sauce and oil for caloric density) and veggies for dinner.

After a large dinner, I’ll try to eat some sweet but protein-rich foods like protein-fortified oatmeal, milk, and/or Greek yogurt.

The last rule is that I’m not allowed to just sit on my ass (or sleep!) all day. I have to get up and at least go for a walk or be active in some way, though I won’t be fasting during a normal workout day.

What happened before, during & after my first 24 hour fast

Here’s a timeline!

1 pm Wednesday – I work out. It’s leg day! I have a good workout and leave the gym feeling pretty good. I weigh in at 138.4 pounds (at 5′ 5″) fasted before my work out.

8 pm Wednesday – Dinner. Spaghetti with chicken meatballs. I eat up knowing my eating-window is about to close for a long time!

9 pm Wednesday – I finish off a post-dinner snack of protein oatmeal and a big glass of milk. I have to force this down a little, and I’m stuffed. Normally I would eat this post-dinner snack a half hour to an hour later, right before bed.

(Note: I really wanted to stop eating earlier in the night than this, but alas, life happened and the schedule got pushed back some. Now I have to make it really deep in the day on Thursday without eating.)

I round out the day somewhere around 2250-2500 calories for bulking.

7 am Thursday – I wake up. I’m about 10 hours into the fast at this point, which is nothing. Though I stopped eating slightly earlier than I normally would at night, I feel pretty much normal.

730 am Thursday – Black coffee! This is how I always start my day with intermittent fasting.

1030 am Thursday – I’m feeling my first hunger pangs. This is pretty normal during a fast, and I find that hunger comes and goes in waves throughout the day before you eat. However, this is a little earlier than normal for me to be hungry.

I’m keenly aware of the fact that I don’t get to eat for a long time, and it’s a weird feeling. It’s easy to underestimate how much you look forward to eating delicious food just because it’s fun.

At this point I’m 13.5 hours into the fast, give or take.

11 am Thursday – I keep myself busy with work and drinking regular water. So far this is a pretty normal day, as I don’t usually eat anything until around 1 pm or so.

I also check my weight again as a gauge. I’m still exactly 138.4 pounds.

1 pm Thursday – I drink a sparkling water (naturally flavored, zero calories… an off-brand La Croix basically). This is pretty much normally what I would do at this time during my usual 16/8-ish fasting.

130 pm Thursday – I’m not particularly hungry, but I am definitely feeling like I want to eat. I usually eat at this time, give or take. My brain is definitely telling my body that it’s time to eat and that eating will bring me happiness.

Have to just ride the wave and focus on something productive.

We’re a little over 16 hours into the fast at this stage.

230 pm Thursday – I am peeing like crazy, which makes sense. First, I’m drinking a lot of water, and second, peeing a lot is usually a sign of ketosis (when your body begins burning fat for energy and releasing its glycogen stores).

I can feel another wave of hunger.

3 pm Thursday – The hunger (or food cravings) have subsided a lot. But I’m still peeing like a madman.

During this phase of the afternoon, I took my dogs out for a walk at some point to get moving and distract myself.

330 pm Thursday – I decide to treat myself with another black coffee to get me through the afternoon.

At this point the actual hunger is not that intense at all, but the desire for just some kind of flavor or something to do with my mouth is getting stronger.

5 pm Thursday – I’ve just been chugging water and peeing, chugging water and peeing. This has got to be the most hydrated I’ve been in a long time.

The hunger is coming back on. At this point this is the deepest into a fast I have ever been at 20 hours.

I’m going to be ready to seriously crush dinner in a few hours.

6 pm Thursday – I grab another sparkling water. Again, it’s not the hunger getting me (though that’s starting to ramp up), it’s just the desire for something other than just plain water.

I’ve now been fasting for 21 hours.

830 – 9 pm Thursday – The rest of the evening is pretty uneventful, except I am SUPER looking forward to a post-fast feast.

The hunger is there but it’s not overwhelming by any means. I keep busy with my usual end of day stuff and drink lots of water. Surprisingly, my mood and energy levels are really good.

Right around 9 pm it’s finally time to eat!

I ditch my original idea of pasta in favor of something quick: I decide to eat an entire frozen spinach pizza and an extra large chicken breast on the side for more protein.

(I have a toddler and life doesn’t always go exactly according to plan!)

I take it slow at first, starting with just three slices and the chicken breast.

It’s such a bizarre feeling; I can feel the hunger creeping on even as I’m eating.

It’s like there’s this huge void in my stomach that’s dying to be filled!

I end up eating almost the entire pizza (my wife has one slice), the chicken breast, and a glass of wine.

(Side note: When she comes home she mentions I look extremely lean and that my skin looks clear and well-hydrated.)

That’s around 1200 calories total and about 60 grams of protein or so.

10 – 11 pm Thursday: After letting things settle for a bit, I need to take in some more calories.

Before bed I finish off with:

• A protein bar (230 calories and 20g of protein)
• A small glass of milk (100 calories and 7g of protein)
• A Greek yogurt dessert bar (100 calories and 10g protein)

At this point, I’m pretty stuffed and it’s time to get to bed. I’d love to take in a few more calories and some more protein, but I think it’s time to call it a day.

The total tally for my meal(s) after the 24 hour fast is roughly 1650 calories and 100g of protein.

(Conveniently enough, the bulking workout program I’m currently on actually calls for one low-calorie day per week to stay lean.)

Still, I worry that this is a little low and might affect how I feel in the gym tomorrow.

Friday morning: I wake up feeling pretty normal, though I slept like a rock and it takes me a while to shake off the cobwebs.

I also feel a little bit more depleted than normal, which makes sense after a deep fast and a low-calorie day.

I feel lean but not overly so. I did stuff a lot of food into my face in a really short amount of time (1600+ calories in 2 hours, yeesh!)

I weigh in at 138.0 pounds, that’s just under a half pound down from the previous day.

I suspect I might weigh less than that later in the day as my body “processes” all the food I gave it late the previous night..

Friday afternoon: Time to work out. I’m fasted, as usual, and haven’t eaten since 11 pm Thursday.

(I do hit some Kino Octane [Amazon link], my favorite pre-workout for intermittent fasting.)

To be honest, it’s not my greatest lift ever. It feels like my top-end strength is there but the endurance just isn’t.

I definitely feel a little bit more drained than usual. I think this has more to do with the low calorie intake on Thursday vs the actual fast itself.

At least, that’s the theory.

I get in a decent workout when all is said and done. I’ve had far better but I’ve also had worse.

Before and after my 24-hour fast photos

Alright, alright. I know you want to see the results (if there are any to see).

Here’s a quick shot of my face before and after doing a 24-hour fast.

(Excuse my bedhead! I took these first thing in the morning the day before and the day after.)

I think there’s noticably less puffiness in my face in the After shot, and maybe even a more consistent skin tone. Am I imagining it? What do you think?

And here’s the body and midsection. Again, I think the difference is VERY small, maybe imperceptible. (After all, the scale shows about .4 pounds difference, which is practically nothing), but I do think there’s more leanness in the After photo, especially in my lower stomach area.

(That’s where my body loves to hold fat.)

It’s not much, but it’s definitely an incremental improvement in terms of leanness.

It could be fat, it could be water retention, it could be both, but I definitely think I came out of the 24 hour fast a little bit leaner.

(Here’s the full shot before and after. I have to say I nailed the posing here. I’m standing in the exact same spot and posing the exact same way before and after. Anyway, I could be imagining it but I definitely think I look like, 10% puffier in the Before shot.)

Will I do it again and would I recommend a 24 hour fast?

Getting through a full 24 hours without eating was not nearly as hard as I thought it would be.

(It helps that I’ve been bulking and eating plenty of calories… It would probably be harder to do a 24 hour fast on a cut when you’ve been eating in a calorie deficit for a while.)

I really thought I’d be famished by the end and tempted to break the fast and start refeeding early.

But I found that a 24 hour fast is really not that different from other forms of intermittent fasting.

Hunger comes and goes in waves. You may be starving one minute, but if you hydrate and focus on something else it will fade.

I learned that hunger is SO much more psychologically driven than anything else.

Eating is fun. It triggers the pleasure centers of your brain. It can be social. It breaks up the day and can be a reward for a job well done.

But does your body really need to eat every time you feel hungry? Probably not. Most of us will never even come close to the point of needing food to prevent starvation.

I can definitely see myself doing this again to flush my system and shed a little, tiny bit of fat at once, but I can’t see myself doing it super frequently.

Eating is truly one of life’s great pleasures, and while I enjoy intermittent fasting, I don’t want to feel like I’m depriving myself on a regular basis.

But I’d recommend anyone who’s interested in fasting give an extended, 24-hour fast a try because:

• It’ll (surprisingly) help you improve your relationship with food, hunger, and your own body’s signals
• You’ll hydrate like crazy and “flush your system”
• You will burn a little bit of fat and come out looking a tad leaner
• You’ll feel great about your ability to exercise discipline and self-control
• It will force you to eat fewer calories (if that’s your goal)

Related: Should you do a 24 hour fast while bulking?

It’s hard to say based on a sample size of one time.

For me, I just found it too difficult to get all the calories and protein I needed in a severely restricted eating window.

It’s hard enough to eat in a surplus when you’re eating all day, let alone cramming that many calories into like a 3-hour window.

I think the long fast and the low calories definitely led to a less-than-great workout the next day.

BUT… I do think it helped me lean out a bit, so in some respects, it might have been a decent trade-off.

What I might try, instead, is incorporating some longer fasts (18-20 hours or so) occasionally into my week, especially on rest days.

That gives me a little more time to eat enough and should give me some of the additional benefits of a longer fast.

If you want to try a 24-hour fast on a bulk, just make sure you structure your day with enough time to get all of the calories you need. And plan your post-fast meals ahead of time to get the right macros!

Related: Can you do a 24 hour fast every day? How about once a week?

You can do a 24-hour fast every day, and a lot of people do!

That’d be pretty similar to the style of eating known as OMAD, or One Meal a Day.

A lot of dieticians and health experts don’t advise sticking with an OMAD diet over a long period of time. Conservationists, however, tout the benefits of eating only once a day (especially plant-based) for resource consumption and environmentalism.

You could easily do a 24-hour fast once a week. And, in fact, this might be a great idea to stay lean while you’re bulking or just occasionally “flush” the system out.

Try it once to see if you can tolerate it, and if you have any health concerns, DEFINITELY talk to a doctor first.

Wrapping Up

Trying a 24-hour fast was definitely a cool experience, and I felt proud of myself for making it through at the end.

I do think there were some solid benefits, like waking up a little leaner the next day, and getting super-hydrated from all the water.

24-hour fasts or OMAD probably aren’t 100% ideal for bulking, but for weight loss they can be a great strategy to kickstart fat burning.

Let me know in the comments if you’ve ever tried it, or if you’re considering giving it a shot!

(If you’re interested in fasting, especially as part of the Ketogenic diet, consider getting a Keyto breath sensor to better track your progress and get helpful biofeedback.)

Hope this was helpful!

You will always read various articles emphasizing the value of healthy eating and role of good lifestyle practices on health. There is no myth when someone tells you that you need to change your habits to improve your health.

One of the most common practices that people normally do is not to eat for a whole day. Sometimes it is done on purpose. Other times it is a part of weight loss regime or the so-called diet practices. Either way, it is causing more damage than the benefit to you and you may not know it.

Want to know how it harms you? Read the complete article to find the answer.

Is it normal to not for the whole day?

Absolutely not. Not eating for the whole day, 24 hours is not a normal practice. People forcing the dietary tips to be tried on you will tell you that it is a form of intermittent fasting and you should definitely try it.

Intermittent fasting is a non-eating practice in which you starve your body for some time. Not eating anything for the day is the most severe form of intermittent fasting and is never recommended.

RELATED: 16 Ways to Lose Weight Naturally

In 24 hour intermittent fasting, you are only allowed to take the calorie-free drinks such as coffee, tea, water etc. When this time is over, you can start eating normally until the next fast begins.

The intermittent fasting is helpful to lose weight. It also adds positivity in health by promoting metabolism, cardiovascular health and what not. But it is not recommended to do daily. It is only safe when you are doing only twice a week. Anything more than this will bring damaging effects to the health.

Intermittent fasting looks easier when you read it. Instead of reducing the calories of the food, you rather fast and then eat your regular food. This idea sounds interesting but it also has severe side effects that may hit you. It may also cause complications in people that have underlying medical conditions and still trying to do intermittent fasting.

That is why you need to consult your doctor first before you plan to start a diet. The doctor can advise you on your individual benefits and risks for the diet. Avoid reading open discussion threads online as the results may vary from person to person.

What happens inside your body when you fast?

Your body will take time to realize that you are following a 24-hour fasting period. You will be good before the body realizes this. The first eight hours of the fast will be easier. The body will be busy in digesting the last food intake of you. It will use the stored glucose as energy and it will function normally considering that you will be eating soon, adding fuel to it.

After these eight hours, your body will not have any more food to digest. Now it will begin to use the stored fats inside the body for energy. The body to create energy for whole time span when you aren’t eating sometimes uses the stored fats.

RELATED: The Myth Of Intermittent Fasting Explained

If your fast is lasting for more than 24 hours, it may lead to your body’s natural mechanism of protein conversion to energy as well.

What are the benefits of 24 hours fast?

Unfortunately, there is currently no research to tell if it has any benefit for the body. More than the actual thing, it is the psychological effect that makes people do this 24 hours long fast.

More research is required to tell if it has any benefits for the body or not. For now, there are only limited known benefits such as;

It makes you lose weight

If you are fasting for once or twice a week in which you are eating reduced calories you are more likely to lose weight gradually. It is more convenient to follow a restricted calorie diet every day for long term. The food intake at the start of the diet may benefit your body by supporting the metabolism, digestion and in this way promoting the weight loss.

It maintains cholesterol and sugar level

If you make fasting a regular habit, it will improve how your body metabolizes cholesterol and sugar. All these changes made to the metabolism makes you less risky for developing chronic conditions related to cholesterol and sugar such as diabetes and cardiovascular disease.

Reduced risk of coronary artery disease

By following a 24 hour fast helps to reduce trimethylamine N oxide level in the body. If there are higher levels of this compound in your body, it brings an increased risk of coronary heart diseases.

Other benefits

The 24-hour fasting also helps in following ways

• It reduces inflammation
• It reduces the risk of certain types of cancers
• It reduces the risk of neurological conditions (Alzheimer’s, Parkinson’s etc.)

What are the common side effects of 24 hours fasting?

One of the most frequently asked questions regarding 24 hours diet is if it has any side effects to show up. People believe that fasting for such long hour leads to side effects and it increases the complications after long term.

It is better to talk to the doctor before you start a 24-hour long fast. It will help to predict the unforeseen health complications for future. This is significantly important when you have any underlying medical condition or a genetic disease.

Who should not fast for 24 hours?

You should not do 24 hours and basically any type of fasting without consulting your doctor if;

• You are underage
• You have an eating disorder
• You have diabetes
• You are pregnant
• You are breastfeeding
• You are recovering from surgery
• You are taking certain medicines daily

Remember if you fats for more than two times per week, it will increase the risk of heart arrhythmias and hypoglycemia in you. For more potential benefits, there is a requirement for more research.

Intake of water during the fast

It’s important that you are making your body hydrated when fasting. As you are not eating anything, the body may deprive of water at this time. Water is essentially required for the body systems to work i.e. digestion, regulation of body temperature, joints, and tissue health, energetic boost etc.

RELATED: Coconut Oil For Weight Loss- Yay Or Nay?

Increase your water intake especially when following a 24-hour long fast. The daily water intake may vary from person to person. On average, men should drink 15-16 glasses of water per day and women should drink 11-12 glasses of water per day. If you are drinking more than that, it is perfectly normal.

What to eat before and after the fast?

There is no specific time to follow 24-hour fast. You can perform it anytime that you want. You just have to prepare your body for it in advance, at least a day before. Eating healthy and regulated meals is the key to prepare the body before time.

Try to eat these foods before you start fasting.

• Protein-rich foods (Nuts, butter, beans)
• Dairy products (yogurt)
• Fruits
• Vegetables
• Whole grain starch

Drink plenty of water and other calorie-free beverages during the fast. Make sure that caffeinated drinks may make you dehydrate so always balance your water intake if you are taking caffeinated drinks more than twice a day.

After you finish your fast, start eating healthy again. Avoid the overeating after the fast. It is better to start eating in small meals to get your body system back to work.

The final word

A 24- hours fast need careful administration. It is not as easy as it looks like. Talk to your doctor before you attempt to do it. Your doctor will be able to tell you the individual benefits and cautions if any. It is better to fast by following a safe way.