Will Intermittent Fasting Cause Me To Lose Muscle?

This video is a free preview of my 6.5-hour course called Intermittent Fasting: Fast Weight Loss That Lasts. This link will take you to the full course:

In this video, Dr. O explains why smart Intermittent Fasting does not cause you to lose muscle.

Medical and Health Disclaimer:

This Video Presentation is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or symptom. Never disregard professional medical advice or delay in seeking it because of something you have read or seen on this informational and educational Video Presentation. Your use and reliance on this Video Presentation is at your sole risk. If you believe you may have a medical emergency, call 911 immediately.

[GrowGrayMatter]

This video is a free preview of my 6.5-hour course called Intermittent Fasting: Fast Weight Loss That Lasts. This link will take you to the full course:

[Grod]

Probably the best video I've seen on the subject so far. Most videos are a one-size-fits-all approach. The only downside to the calculations are that one would have to get a dexa scan to get an accurate body fat %. Don't know how accurate online calculators and myfitness pal is, as far as calculating maintenance calories

[EZ_man_]

I am 6'2" 305 right now.. Back on a keto ride for a couple weeks already, and lost about 10-15lbs. Done IF quite a bit over the years, 16:8 20:4 and omad.. but had not really heard about ADF.. I am at 28 hours right now.. Thanks for the intel!

[barbstevenson]

Thank you Doc. It looks like I have quite a few pounds to lose before I have to worry about being too lean for alternate day fasting. I appreciate you.

[travisshaffer]

This is a good video. You explain stuff that most “diet pushers” never discuss.
They should.

[lawrencetorrance]

Great video, thank you. There has been talk lately of a different study that found intermittent fasting destroys muscle more than regular feeding, when calorie intake was held constant. But I think that study was done on people who were not overweight.

[tankthearc]

i do 18 hour daily fasts with great results, lifter too. but im wondering can i do a 3 day fast without losing muscle?

[norm]

Just the VIDEO I've been searching for! Thanks!!

[thetennisplayerdietitian]

Could I eat the extra 433 kcal (1700-1266) on my Eat days and just do alternate day fasting with zero food in between? I’m doing heavy weightlifting 4 x a week and walking 10K steps a day and eating 1g per lb bw of protein

[dougburrell]

What a great source, thank you. So this is related to only ADF? For example: I can get 2371 k from fat so I would eat normally every other day then adjust my fast day depending on level of activity.. So if my activity was moderate for the day then I would consume 721 k on the fasting day. Is that correct?

[romi]

Thank you so much for simplifying the calorie question. On which site can I calculate my maintenace calories?

[victorycall]

These videos have enhanced my understanding of how the body fuels itself during fasting. Yes, the body utilizes its fat stores, but it is understandable that the body can only mobilize so much of its fat so quickly. After doing my Navy bodyfat measurements and the maintenance calories calculator, I need 2312 calories per day for maintenance, and my bodyfat can supply 838 calories. So on a "fasting" day I should still be eating 1474 calories to avoid losing lean mass... in other words, not fasting at all. I generally do OMAD or 2MAD eating, low carb / high protein, and I want to maximize my time in autophagy to stave off neurodegeneration. I did a 4-day fast a year ago and it went great, I said "I'm going to do this quarterly." Then 3 months later I started a fast again, and I felt like such garbage after 2-and-a-half days I called off the fast. Now in retrospect I understand that during my second fasting attempt, I had less bodyfat stores to pull from, and I would have started pulling from my lean mass, hence feeling like garbage. It sounds like daily OMAD is the most prudent eating style for me now.

[MattCardJacket]

Hey, Doc, fascinating.Thanks for sharing it. Because this is dynamic in nature, how often should I reassess and adjust? Is weekly not necessary; perhaps every two weeks (assuming I can lose between 1 and 2 pounds a week and that it's all fat)? I'm 65, former athlete, 195lbs, 23% BF, bradycardia (below 40 in sleep). Maintenance is about 1800 cals. do compound lifts 2 to 3 times per week (bench, squat, military and deadlift), walk 10ish miles a week with a few sprints. Thanks again.

[اناليبي-فز]

Thank you for this info it solved the mystery for me 🎉

[drmustafa]

the calculation will chance with each pound loss. Besides to increase body's resistance to chemotherapy or reduce insulin resistance the priorities change. preserving weight in cancer patients can become a real challenge. I wish there were more randomized clinical trials. Since these will remain limited for some time, navigating through mayhem of the body is a mammoth task..
Another point is that autophagy related calorie gains. another one is metabolic rate varies between individuals.
Blood glucose is maintained even in prolonged (days to weeks) water only fasting. there is more to body than some simple calculations. when considering all other organisms, even beyond body...

[Celinekho]

00:32 🤔 Fat isn't just fat; it contains 13-16% lean mass. Losing fat might show as lean mass loss, complicating weight measurement.
02:38 🔄 The key is understanding the energy your body fat can provide; excessive diet restrictions lead to immediate fat-free mass loss.
03:20 📊 Calculating energy transfer rates helps tailor fasting; ballpark estimate is 29 to 34 calories per pound of fat.
04:15 🏋‍♂ Real-world examples showcase how different body compositions affect fasting approaches; personalized strategies are crucial.
06:06 🍽 Fasting safety depends on body composition; individuals with lower body fat may need modified fasting approaches for muscle preservation.
07:28 ⚖ Personal example: Fasting can still be effective even with significant weight loss, but caution and adaptation are necessary for sustained muscle preservation.
09:22 🏋‍♀ Building muscle during fasting is possible; combining fasting with resistance training helps preserve and even increase lean mass.
09:51 🚫 Avoid aggressive diets without weightlifting to prevent muscle loss; resistance training signals your body to preserve lean mass during fasting.

[kenk]

Based on the calculation of 30 calories energy production per pound of fat, my metabolic rate, and the amount of body fat I have, I shouldn't need to consume any calories at all for at least two months. And that's if I'm being athletic.

[MattCardJacket]

Actually, 1800 calories was my BMR. Maintenance should be around 2900

[FretBuzz_]

My experience so far comming from 125kg to 114 kg in 2 months with 48h and 72h fasting. Since 3 weeks now I also lift weights (40-60 min per day, 5 or 6 days per week) and 1h-1h20' walking 4-5 days per week. Before these 3 weeks I was doing only walking.
The state where I am in now is that I have 33% body fat (or 82lb) which leads me @30calories / lb to ~2.500 calories provided by my body fat.
For the active lifestyle the calculator says that I need ~3.500 maintenance calories. However, I must be in calories deficit to loose weight. So techically I have a 1.000 calories deficit (I keep up with daily exercise rutine also in days when I am not eating and I don't estimate to eat more than 3.000 calories in the day when I eat).
On positives is that I am doing well, energy level is good, I don't feel dazed (I also do my regular 8h office job).
I hope to reach an optimal weight of 80-88kg depending on muscles mass when I will have probably to revert to a time restricted schedule instead of this which to many I talk with sounds a very agresive diet.
Question is, am I in danger to loose lean mass with these parameters ? Is the calories deficit too high (based on these calculations) ?
My primary objective is to loose weight and I do exercises for body shape (I don' aim to become a body builder, only to don't become fat skinny or things like that).
I also target more sophisticated aspects like autophagy and celular repairs as I am 39years old now.

[stephengallagher]

Ah, I get it, but have a question. So, I'm a male, have 70lbs of fat, 2100 energy can be provided. My maintenance is 2350. I need to eat 250 calories per day to avoid catabolising muscular tissue. But Doc, I am doing IF, stretching it from 16/8, to 20/4, to 23/1 OMAD, getting great results. I was about to take the next step, and do a 48-hour fast. *Would even one or two days not getting those 250 strip muscle?* I am muscular, lift weights 6 days a week. Eating 1200-2000 in my feeding windows. Lots of exercise and water. Thanks, Doc! Up the Irish!
Edit: Think you answer in the video. I can fast for days, but need 250 to stop muscle loss. I take two tbs EVOO fasting already, if I double that, or so, and it makes the 250, I can do 48 or 72 without losing muscle? But 250 has me covered if I don't exercise. If I lift weights and do a hike, then would I need to eat those calories too? Was hoping I could eat the 250, bank the rest as fat loss, and keep my muscles.