How much weight can you lose on a 96 hour fast vs intermittent fasting?

Scientifically speaking this is how much you can lose on a 96 hour fast:

The first thing you need to find out is how many calories you burn per day. You can either use a Fitbit, apple watch, or any calorie tracker of your choice. For me the Fitbit is extremely useful as is the apple watch. They both give very similar readings but the Apple Watch has a battery life of about 18 hours which means it ends up being about 10-20% off on a daily basis. The Fitbit doesn’t have this problem and if I had to recommend one I’d go with the Charge 5.

If you google “calorie calculator” you can enter some basic information and it’ll give you an average estimate of how many calories you burn per day. If you want a complete breakdown of how many calories you burn, macros, and a full fitness assessment check out the products I offer above. So let’s get down to the science.

One (1) pound of subcutaneous fat contains 3500 calories. This means that in order for you to lose 1 pound of body fat you need to create a 3500 calorie deficit. If you have a 500 calorie deficit per day this means you’d lose 1 pound of body fat every 7 days.

When you fast it means you are consuming zero calories per day. If you don’t exercise you are burning whatever your Basal Metabolic Rate (BMR) is. Let’s start with a typical woman example.

Using the calorie calculator I linked above, let’s calculate the following scenario:

Scenario 1:

A woman who is 30 years old, is 5’3, and weighs 140 pounds has an approximate BMR of 1490 calories per day. A 96 hour fast is 4 days which means that over this period of time she’d create a 5,960 caloric deficit. This amounts to a total fat loss of 1.7 pounds. If you include water loss from glycogen and fat loss her scale weight loss would be anywhere from 2.4 pounds.

Scenario 2:

A man who is 30 years old, is 5’10, and weighs 220 pounds has an approximate BMR of 1964 calories pe day. This means that over a 96 hour period he’d create a 7,856 caloric deficit. This amounts to a total fat loss of 2.24 pounds. If you include water loss from glycogen and fat loss this will amount to about 3.2 pounds on the scale.

Some elements that need to be considered when looking at total weight loss on a body weight scale is glycogen depletion and the emptying of your bowels. This can add significant scale weight loss but it’s not fat loss. The weight lost from glycogen depletion and emptying of your bowels you’ll get back once you start eating again. So if you want to think about it in terms of how much permanent weight loss you can expect is the fat loss not the weight scale loss.

Intermittent Fasting (IF) is a powerful tool but it’s not something you need or have to do.

Intermittent fasting should be used strategically. 24 hour and longer fasts can provide great benefits such as autophagy, but per my experience, it is not an end all solution to obesity. To defeat obesity you must lead a nutritionally healthy lifestyle filled with physical activity.

Let’s break down intermittent fasting with the following topics.

Why do I intermittent fast?

I practice a 12 hour fast because it helps me keep my calories under control. I follow a very simple strategy which I will discuss below. As an active person considering that I’m a personal trainer and I love to compete in anything fitness related my caloric demand is pretty high. Despite the high levels of activity I am also a big eater. I love to eat! I’m not a very big guy and weigh about 180 pounds. I burn approximately 2700-3500 calories a day depending on how much I train.

By fasting 12 hours or more I reduce the amount of meals I have per day making it easier for me to control my calories. It’s usually easy for me to hold off until the afternoon before my first meal. The problem arises once I start eating. I open the flood gates and it’s non-stop eating until I go to bed. If I start eating early in the morning then I’ll easily surpass 3200 calories consumed. I save this for the days I know I am going to train hard and possibly have two – 2 hour training sessions. On my easier days and recovery days I wait as long as possible before my first meal.

On a side note, the above paragraph was written years ago. As of 2021, I have the developed the ability to control my hunger. I now eat breakfast at around 7:30-8:00 am and only eat 3 meals per day with my last meal around 6 to 7pm. I have zero issues controlling my hunger. This is from the previous years of practicing a 14-16 hour fast while eating for only 8-10 hours. I am constantly preaching that the body adapts to everything including your eating patterns.

Time frame guidelines for different intermittent fasting strategies:

12 hour fast:

This should be a minimum as a general health approach. Whether you eat your last meal at 8pm and fast until 8am the next day, or 5pm to 5am, it should be part of your daily life. In my life this is the approach I take when I have a very active day. It keeps me on target for a 3200 calorie intake day without overeating.

18 hour fast:

Some people have very busy lives and tend to not eat for long periods of time. As daily practice, in my opinion, this should be the maximum fast with 2-3 meals during the 6 hour eating period. On my days off or very low activity days I do a 14-18 hour fast. It isn’t too hard for me and it helps me stay at around 2500 calories.

24/1 hour fast:

Eating once a day, as healthy benefits as it may have, I wouldn’t recommend it for most people unless they have a very low activity lifestyle. It’s definitely a powerful tool for people wanting to lose weight, but for those seeking performance, I’d steer away from it. Your body needs energy! Unless you can eat 3000 calories in one sitting as an athlete, I’d stick to 12/12 or 16/8. If you don’t eat enough calories your body can enter starvation mode and steer away from health. If you do 1/24 make sure that you eat enough calories, take your vitamins, and any other necessary health supplements.

24-48 hours:

This type of fast I’d do once every 6 months more or less. More then anything to reset the body,  detoxify, and maybe lose a few pounds after a period where you may have gone a little rogue, it’s not something I’d do too often. As a weight loss strategy, you can do a 24 hour fast once a week and stick to a 16/8 the rest of the week while maintaining a 500-800 calorie deficit, preferably around 500.

48-96 hours (and longer):

Technically, some people have fasted for more then 7 days. Most people do not need to go this long. I’ve done up to 96 hours and it’s not as difficult as some may thing. I’d start with shorter fasts, like 48 hr before attempting a 96 hour fast.

As all things, make sure you always consult with a physician before attempting any type of fast exceeding 24 hours. A few tips, drink a lot of water. Do not try to take shortcuts by using artificial sweetners. Executing a fast without shortcuts has fantastic benefits such as autophagy, sugar regulation, detoxification, and more.

My 96 hour fast personal experience:

Step 1 – Strategy:

The first thing I am doing is strategizing. My schedule has Tuesdays, Thursdays, and Sundays off. I run a YouTube Live workout class Mondays, Wednesdays, Fridays and Saturdays. My last meal will be Sunday night. Monday I am going to do my YouTube class which is around a 70 minute workout for Chest Shoulders and Triceps. Later in the day I am going to go for a 6.5 mile walk. Essentially I am going to deplete my glycogen stores extremely fast and I’ll probably be in a ketogenic state within 24 hours. It’s also a great way to maximize my calorie deficit since I’m still energized and my body has no idea it’s going into a 96 hour fast. I also decrease the time it takes my body to enter autophagy which means my body will start recycling useless protein such as excess skin. I’ll be drinking coffee and a glass of natural lemonade with a pinch of salt and a little tabasco sauce. I plan to still workout and I’ll be drinking an energy drink but only when I train. I honestly don’t believe my zero sugar zero calorie energy drink will destroy my fast especially since I’m overwhelming my body and burning a lot of calories. In addition to everything aforementioned I’ll also be taking my fat burner twice a day and a multivitamin once a day.

Supplements:

Liquids:

  • Coffee
  • Natural fresh squeeze lemonade (2 limes with a pinch of salt, about an ounce of apple cider vinegar, and a couple grams of tabasco in about 16-20 ounces of water).
  • To be honest: I will drink a zero sugar beverage such as Kirkland Zero Vitamin Water with dotFit Super Creatine XXXL or a Reign Pre Workout drink before and during my workouts ONLY!.

Step 2 What to expect:

My scale weight is 181.2. I am going to use a net 179lbs as my variable to figure out these estimates. My BMR at 179lbs pounds is around 2000 calories per day. My active calories for a workout are around 500-600 calories per 70-80 minute workout. Every 6.5 mile walk helps me burn around 900 calories. My walks are always with a 15-30lb vest. If we add it all up 2000+550+900 = 3,450 calories. One pound of fat is about 3500 calories so on Monday I’m expecting to burn close to 1 pound of fat. Typically you’d lose about 1 pound of water weight per pound lost. I’m also burning glycogen. My body holds about 280 grams of glycogen when full. Every gram of glycogen carries 2.7 grams of water. After some math this results in about 2 pounds if I were to burn up all glycogen. However, your body will produce some glycogen so you’re not always empty. I’ll say that my glycogen depletion will result in about another pound of weight loss on the scale. My bowels will be empty as well and I usually eat about 3 pounds of food per day of which let’s say half gets consumed. I don’t think I’ll be completely empty by day 2 but let’s say I lose another half a pound. On day 2 I expect to wake up, 2+1+0.5 = 3.5 pounds, lighter. So on day 2 I expect to weigh 177.7 lbs.

On day 2 I expect to lose weight only from fat loss. It’s a day off so I’m only going to be burning my BMR which is around 2000 calories. This is equal to (2000/3500) 0.57 lbs. If we include water weight I’ll keep it simple and say I’ll lose another pound. At the beginning of day 3 I estimate my scale weight to be 176.7 LBS.

On day 3 I expect to do my YouTube class which will be another 70-80 minute class. It is not advisable to workout during a fast but I’ll play it by ear and proceed unless I feel terrible. If I do the workout my total calorie burn for the day will be approximately 2550 calories. This equals about (2550/3500) 0.72 lbs of fat loss. If we take water loss into consideration I expect to lose about 1.5 lbs of scale weight. On day 4 I estimate my weight to be 175.2.

Day 4 will be similar to Day 2. If all things remain the same I expect to lose another pound of scale weight. This will bring me down to 174.2 lbs on the morning of Day 5 when I’ll be finishing the 4 day fast.

In summary I expect the following:

  • Fat loss will be about 3.5 pounds.
  • Lean body mass loss due to fasting I estimate to be about 2.25 lbs.
  • Total weight loss after 96 hours will be about 7.71 lbs on the scale.
  • On Friday I will be doing a Glycogen Supercompensation where I’ll be consuming an extraordinary amount of carbs in comparison to what I can store. Because I’m completely glycogen depleted and I’ll start eating after I workout my body will be primed to absorb extra glycogen. That is what I hope.
  • Since I’m finishing the fast on Friday I expect to gain about 5-8 pounds back by Saturday morning. So my scale weight will be between 179-180lbs. I expect my new walking around weight to be around 178-180 pounds but hopefully without gaining any fat due to the Glycogen Supercompensation. In other words, I expect my lean mass to go from 156lbs to 157-158lbs.

Final Results from my 96 Hour Fast (Actually 111 hours):

Body fat: Using the Parillo Method, Day 1 (Monday) I had a body fat measurement of 13.73%. On Day 4 (Friday Morning) I had a body fat measurement of 12.86%. This results in a little under 1% drop and the summary in terms of fat loss and lean body mass is as follows:

  • Fat loss = 2.2 lbs: My estimate was that I was going to lose about 3.5 pounds of fat. According to body fat this was not the case. Does this mean that the math is wrong? No it does not. It could be a flaw with the body fat test. The calipers may not be calibrated correctly. There could human error when it comes to pinching in order to get the site measurements. It could also mean that my metabolism is not as fast as I estimated. Another explanation is that my body may have also broken down and recycled more useless protein through the process of autophagy and thus it’d be protein breakdown not fat breakdown. In the end it is an estimate and the bottom line is that I did lose a significant amount of body fat. What I’ll do is modify my formulas to narrow the flaws of the estimates and get them to reflect and compliment each other. I will also take into consideration autophagy.
  • Lean body mass loss = 2.8 lbs: My estimate was that I’d lose about 2.25 lbs of lean body mass. It seems as if I lost a little more. What this indicates is that I may have the capacity to store my glycogen then I calculated. It means I have more muscle mass then I thought. This also will result in yielding less fat mass loss. Which is what happened. In the end I must take this into consideration so that my formulas can be more accurate.
  • Total weight loss = 7.6 lbs: I used 179 lbs as a net weight to take solid waste into consideration on Monday when I weighed in. The scale weight was 181.6. If I use the net weight I lost 5 pounds exactly. According to the measurements I should have lost about 5.71 lbs. Again, I subtracted 2.1 pounds to get a net of 179 lbs. This could easily mean that I was hold 1.5 pounds of solid waste not 2.1. This is human error and again it’s just an estimate. In the end I believe I have a very good grasp of what’s going on. Usually you want estimates to be conservative and the results to be better then expected. In this experiment I was very close to matching and with a few modifications I think I’ll be close most of the time. It’ll never be perfect.
  • In regards to the Glycogen Supercompensation I woke up on Saturday morning at 178 lbs. I was expecting to be around 179-180. I still have another very high carb meal left so the official walking around weight measurement will be Sunday morning and then keep track of my average weight during the upcoming week. All in all I believe I will be very close.

Conclusion to 96 hour fast:

I am very happy with my estimates vs my results. I will be making some slight adjustments to get more accurate numbers. My goal from this point forward is to fast for 36 hours once a week as a strategy to get myself into contest shape. I will be following up with that. Check out my instagram and my facebook page to keep up with my progress.

How I intermittent Fast as part of my life:

intermittent-fasting-schedule-weight-loss
Intermittent Fasting Benefits

Although I’ve done a 96 hour fast before, I wouldn’t practice any fast longer then 12 hours. This is because I’m already very lean, I carry a lot of muscle, and I’m very active. I also train with high intensity, large volumes and heavy loads. I can’t be fasted if I want to perform to the highest of my abilities.

Recommended diets for intermittent fasting:

Keto:

This is a high fat, moderate protein, low carb diet. The main reason this diet became popular was to maximize weight loss in ketosis. Fats ad proteins have been shown to be more satiating and play much more important roles then carbs. Carbs although useful for performance are not really necessary. However, you can still gain weight in keto if you don’t watch your calories.

Custom Keto Diet

Fat Cycling:

Very similar to keto you don’t have to maintain such high percentages of fat. You can reduce your fats to about 50% of your calorie, eat enough protein to provide maximum repair and recovery for the muscles, and you can eat carbs strategically to help you with maximum performance.

Fat Cycling Diet – Keto ish Weight loss system

Fitness Adaptations Intermittent Fasting Routine:

Sleep – 11:00PM – 6:30AM

7:00AM

At this time I have breakfast. I have a very specific breakfast that includes high fats, a protein cookie, protein shake, a banana, and milk. It is a very balanced meal, but it is strategically designed to help me perform my workout at 11am, but also carry my until my next meal which I usually consume around 2pm. If I want to lean out and lower my calories, I’d push this meal to after my workout or as my second meal. What ends up happening is I eliminate a meal usually my 4th meal.

Lately I been using myproteinbite cookie as the cookie, but sometimes I use a fat snax. It all depends on what I am in the mood that day, whether it’s a chocolate chip cookie, which fat snax is my favorite chocolate chip and double chocolate chip, or snickerdoodle which is what I get from my protein bites.

On average this meal adds up to about 900 calories due to the high fat content. Because of the high fat content and good amount of protein, I do not need to eat until after my workout.

Buy them here:

Here is a video of my breakfast, and a quick guide as to how I weight my food. In my opinion, this is the perfect breakfast.

https://youtu.be/9e5KO7sg6Ms

10:30am

Around this time I prepare my preworkout with about an ounce of apple cider vinegar. I sip on it and I also take my fat burning pills so that I can have a great workout. Both, the pre-workout and my fat burner increase my energy and improve my focus. If you’re caffeine sensitive, mix the apple cider vinegar with AminoBoostXXL, an amino acid drink from dotfit. Check out the performance supplements here, including the preworkout and the aminos: Pre workout drink for energy

Braggs apple cider

12:30 PM (I workout from 11-12pm on Youtube Live so join me, Get in Shape with Fitness Adaptations)

Around this time I’m wrapping up my workout and most of the time I’ll have a protein cookie. My protein cookie of choice is from myproteinbites.

2pm:

At this time I’ll have my first meal (not including breakfast). To make it as simple as possible, I usually eat around 4-6 ounces of meat or fish, 150 grams of carbs total (rice and beans, potatoes, casava, don’t matter), and 2 eggs. This meal adds up to about 700 calories.

Lately I been eating two slices of toast, with butter, two eggs, and 2 slices of bacon. It adds up to about 640 calories.

5pm

At this time I’ll eat my 3rd meal. Very similar to my 2pm meal (the 1st version). I usually keep track of what I’m eating on myfitnesspal, and how many calories I’ve burned on my fitbit, and I’ll make a decision if I want to eat just a little less, a little more, or keep my meal size the same.

7pm

At this time down goes my 4th meal (again very similar to meal 2 and 3 but a little smaller). If I’m trying to lean out I’ll usually skip this meal. I may have a snack instead to ensure I hit the caloric deficit I desire.

In regards to snacks I usually have a 300 calorie snack. I may skip it if I’m too high on my total intake. If we add up all the calories my normal caloric intake is 900 + 650 +650 + 500 + 300 = 3000 calories.

I will not eat again until the next day. Many times, I workout again, maybe an easy 45 minute cardio session, I may have a small snack such as another myproteinbite or fat snax. Sometimes, post workout, I also might have a protein shake, 2 scooops, with coffee instead of the protein cookie.

Intermittent Fasting Conclusion and Tips:

I ain’t hard! It’s only hard if you don’t have desire or discipline. Ideally, you should avoid the amino acids during your fasting window exceeding 24 hours if you want all the main benefits of a fast. There is no point in fasting unless you are getting all the benefits. Coffee and green tea, without any sugar are okay.

Frequently Asked Questions about Intermittent Fasting:

How long should I do intermittent fasting?

The truth of the matter is that you should intermittent with a purpose. Different time frames have different benefits. If you need to lose weight you should IF fast for as long as it takes for you to reach your goal but I’d avoid doing fasts that are longer the 7 days. You must also understand the health benefits vs the risks. The first thing you need to do is consult with your physician and get his/her blessing. Daily IF fasts such as 16/8 which means you fast for 16 hours and you eat during an 8 hour window is actually a good approach to living life. You can do it for as long as you live. 3 – 7 day fasts and longer cannot be done too consecutively because your body needs nutrition. It also depends on other variables such as whether or not you’re a very active person. This can be dangerous.

What are the benefits of 16 hour fasting?

There isn’t a significant benefit to a 16 hour fast. The only benefit is giving your digestive system a break. However, a 16 hour fast can help you eat less and lose weight because you’ll lower daily caloric intake. Please understand, doing a 16 hour fast does not guarantee weight loss. You must be in a deficit. If you still eat the same amount of calories that you did before you IF, you will not lose weight. You will maintain exactly where you are currently. My advice if you want to lose weight is that you speak to a professional who can create a nutrition program designed to help you lose weight.

What are the benefits of 48 hour plus intermittent fasting?

I am not citing any studies with this answer so please do your due diligence. A 48 hour fast can help you lose about a pound of pure fat. How much fat you lose depends on how heavy you are, your sex, and your activity level. On the scale however you may lose up to 5-15 pounds due to water weight and the discharging and emptying of your bowels. Typically, around 48 hours you may also experience autophagy which is the recyling of useless protein which can result in the tighetning of your skin.

Should you intermittent fast every day?

A 12/12, 16/8, and 20/4 can be done on a daily basis. The one thing I’d caution against is undereating. Even though you are eating less frequently throughout the day you can enter starvation mode if you don’t consume enough calories. When it comes to long IF periods, let’s say you do a doctor supervised 10 day fast, even though you are feeding for a long period of time, your body will not enter starvation mode. Starvation mode is what bodybuilders do which I’m totally against for 12 weeks or longer.

Why am I gaining weight on intermittent fasting?

Weight loss happens when you burn more calories in a day then you consume. All foods have calories. If you eat 800 calories per meal, and you eat 3 meals over an 8 hour period, that’s 2400 calories which your body will intake. If you only burn 1800 calories you have a 600 calorie surplus. At this rate you will gain a pound of fat about every 6 days. Watch your calories.

How much weight can you lose in a month with intermittent fasting?

This depends on your caloric deficit. It doesn’t matter if you do a 16/8 or 20/4 or eat once a day. If you consume 1800 calories a day and you burn 2300 calories a day, you will lose about a pound of fat every 7 days. At this rate you’d lose a little more then 4 pounds in 30 days (one month). Take water weight into consideration and the scale may reflect about 6-8 pounds. It all depends on how big your deficit is. Track your calories consume vs calories burned.

How long does it take for intermittent fasting to work?

Intermittent fasting begins to work immediately. If you do a 48-96 hour fast you will lose 1-2 pounds of body fat depending on your current weight, sex, and activity level. If your goal is weight loss then there you go. However, if you do a 20/4 for example, but in that 4 hour windown you eat 2500 calories and you only burn 2000 per day, you will gain a pound of fat per week. It comes down to caloric balance.

How do I start intermittent fasting?

The idea of intermittent fasting is to not eat during a fasting window. If you plan to do a 48-96 hour fast then all you need is plenty of water or black coffee or tea. If you are doing a 16/8 or 20/4 as a lifestyle change then I’d recommend getting a professional nutrition plan that takes into consideration your goal. The nutrition plan should include your caloric intake vs output. It should tell you more or less how long it’ll take you to reach your goal if you’re trying to lose weight, and make an adjustment to maintain once you reach your goal.

What can I drink during intermittent fasting?

You can drink water if you are okay with it. You can also have black coffee or plain tea. The idea is to avoid anything that will take you out of the fast. This includes BCAAs, sugar free drinks, sugar alchohols etc. Avoid them! Don’t try to justify having them for any reason. Either do it right or don’t do it at all. However, if your goal is to only lose weight and you don’t care about the authophagy and other benefits of a fast, then yeah do the bcaas and the zero sugar drinks. You’ll still lose a lot of weight because you are technically not intaking any calories. However, you are not fasting.

How many days a week should you do intermittent fasting?

You can do a 16/8 fast 4 times per week and a 20/4 twice a week, and wrap it up with a full 24 hour fast on the 7th day. You can do this for as long as it takes for you to reach your weight loss goal. On the 16/8 fast I’d keep my caloric deficit small at about 300-500 calories per day. On the 20-4 I’d increase that deficit to about 1000 calories. And of course, on the 7th day you will have a deficit of whatever your body burns naturally. This is just a guideline. It’s a good strategy if you need to lose weight fast. In my professional opinion, you should do this for a couple weeks to get your body to adapt to fasting and then maintain a 16/8 or 20/4 fast for the rest of your life. Just make sure that you understand your body’s needs.

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Build your body step by step with the Perfect Body Shape Formula. First figure out, how much should I weigh for my height? and use these other sub steps included in the process:

Related steps:

Step 2, find your body fat by using this How to calculate body fat percentage | Skinfold caliper vs BMI article (this will be used to calculate current body fat mass and current lean mass).

Once your nutrition is programmed, then learn to workout. How should you be working out to get your ideal body type? How heavy? How many reps? How much rest? If you want to workout from home check out Gymming at Home – Essential Equipment to get my recommendations for tools, equipment, and workout schedule for my YouTube workouts. Make sure you check out my norditrack treadmill reviews if you are interested in starting off your journey by walking or jogging the weight off. I give you tips and guidelines to get the best results.

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One of the most important tools to help you on your journey are tools that will help you track your daily goals. Start with the best fitness tracker with heart rate monitor, whether it’s to monitor calories burned using a fitbit charge 4 or measure the stress levels of each workout and recovery using a whoop bodybuilding. After your workout, make sure you clean up. Check out the microfiber duster mop slippers.

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