Does Intermittent Fasting KILL MUSCLE? (Diet Confusion) – ATHLEAN-X™

by YouTube Team

Stop being confused by how to eat to lose fat and build muscle

Intermittent fasting is certainly one of the most talked about methods of eating to lose fat. It has gained it’s popularity mostly by those who have had some success with it…in the short term! The issue with intermittent fasting and even some of the other diet methods talked about in this video is that they are questionable long term solutions at best.

In fact, a recent study was published that questioned whether intermittent fasting actually killed muscle or led to accelerated muscle catabolism. Given the nature of the diet, it’s easy to see where this research has come from. Going long periods without eating (up to 18 hours) flies in the face of sound long term nutrition principles and respect for one’s metabolism.

I’m not even talking about metabolism in reference to metabolic rate, but rather just the brain’s preference for consistent supply of nutrient rich (glucose rich) blood, preferentially in the form of food rather than through secondary compensatory means that the body has of producing glucose in times of need.

Other diet techniques and protocols similar to intermittent fasting in their “fad” nature include fat elimination diets, the Atkins diet, and juice diets. While all may in fact deliver short term fat loss results, most will never be sustainable for the long haul. They will wind up leaving you fat again and looking for the next short term solution.

In order to burn fat and build muscle most consistently, you need to follow a healthy and balanced diet consisting of fibrous carbohydrates, starchy non-refined carbs, high quality protein, and healthy fats. No macro or micronutrient should ever be entirely excluded from your diet if you want a long term solution.

Athletes certainly don’t screw around with gimmick diets and fad nutrient manipulation knowing how important sound nutrition is to their performance. Neither should you. If you want to see exactly what a sustainable nutrition plan would look like, then be sure to head to and get the ATHLEAN-X Training System and X-Factor Meal Plan.

For more videos on nutrition and diet tips, as well as a video directly on intermittent fasting be sure to subscribe to our channel here on youtube at

source

Related Articles

Leave a Comment

36 comments

AA Fit Life Coaching July 15, 2021 - 7:02 pm

El problema es que vemos las herramientas como el AI como una dieta o panacea para ponerse en forma, y la base es una buena alimentación de ahí todo estas deben ser vistas como herramientas igual que el cardio.

Reply
Emp6ft10in July 22, 2021 - 1:03 am

Anyone able to recommend a really good book on intermittent fasting specifically for weight lifters?

Reply
JakeNukem3D July 24, 2021 - 6:25 am

I do 16/8 intermittent fasting al the time. Three meals a day. Huge improvement in my recovering and lost tons of fat. Also not losing muscle. Going on 3 years now.

Reply
Jus Crank Tackle July 25, 2021 - 8:23 am

Soooo….. does it kill muscle or not?! Lol

Reply
unboppable July 27, 2021 - 8:44 pm

intermittent fasting has been the most sustainable way for me to eat meals lmfao. Any time i tried to stop because people frowned upon it and i thought that maybe I was the one doing something wrong, I would spiral into an eating disorder and live off of junk food. I'd say IF is a lifestyle for those who find it works for them. It's definitely not for everyone though

Reply
Luca Reichmann July 28, 2021 - 6:48 am

I am vegan and do intermittend fasting and feel great. Just make sure to eat enough in between and stack up on the proteins and carbs and good fats.

Reply
OP RAJPUT July 28, 2021 - 8:57 am

Hy

Reply
JUAN SEBASTIAN MORENO RUEDA August 11, 2021 - 1:18 pm

You might see people that claim that IF increases testosterone which is true ONLY on the short term, studies show that after 8 weeks of IF subjects ended up having 20% less testosterone besides testosterone levels being increased in the first week.

Reply
Bryan Martin August 12, 2021 - 1:51 pm

I call it scheduled eating. I like being hungry as the body is cleaning itself. The bes part is when it is time to eat it is time to eat. I do this religiously without thought. For me it is damned sustainable. No snacks. What you eat today you run on tomorrow.

Reply
neil duncan August 31, 2021 - 8:24 pm

Ectomorph tries this and watch how quick they lose fat and muscle. Carbs, if I remember are essential for an ectomorph. Also, complex carbs like oatmeal, don't release sugar in high quantities into the bloodstream. Intermittent fasting is quite stupid. We need fat for organs to function. So IF is bull in my opinion. Each to there own method though.

Reply
Alfred Mkombwe September 1, 2021 - 3:30 pm

Nice

Reply
Hendrick Wijaya September 1, 2021 - 6:22 pm

I was tried Intermittent fasting before on short terms seems works i loss 3-5kg on 2weeks but it kills my muscle a lot , im an ectomorph , so i stick to high protein diet, and also count my own calories (fat,carbs,protein and reduce sugar) ,calorie deficit everyday( mild weight loss 1700 calories, 50-60g fats maks ,120-150g protein per day ) and my muscle growth significantly and my belly fat decreased now i have 15% bf , and i'm going to get 10%bf

Reply
dwayne dwayne September 2, 2021 - 12:52 am

If you are discipline enough to always eat good then maybe you are right. Must of us are not that discipline with our diets so intermittent fasting will help those of us that are not as strong with diet.

Reply
Jeff Chan September 6, 2021 - 11:35 am

I made huge changes when I changed my lifestyle as Jeff was saying. I think that is the goal, to eat and live healthy for the rest of my life

Reply
William Queen September 6, 2021 - 5:00 pm

Completely agree you need to do a follow up on this.. not going to argue.. it works for a lot of people.. I’ve been doing IF for 5 yrs..it is a lifestyle change..it is not a diet and it’s not a fad.. Jason Fung, Eric Berg…Update your info!!,

Reply
Lucas Srinivasan September 6, 2021 - 10:44 pm

Classic Jeff, the title is a question and he doesn't even answer it. 😂

Reply
Waltzs budgetBumpin September 8, 2021 - 7:57 pm

I've been eating one medium calorie meal a day I cut out all sugary junk foods and stop eating meat ( no meat for ethical reasons) and I've lost like 20 lb in a month or so but it looks like I've lost muscle mass! is this likely

Reply
Miniman's videos September 10, 2021 - 2:25 pm

I have only 5 hours per day for eating.., at least 15 years!!..

Reply
Darren Watson September 26, 2021 - 1:20 am

Just avoid vegetable oils

Reply
Andrew Jackson September 26, 2021 - 4:02 am

Carbs are NOT the same thing as fats lmao. Jeff's workout advice is great, but his knowledge on diet is clearly jaded

Reply
Faust September 27, 2021 - 6:32 am

A revisit on this would be very beneficial I think, I've been living IF for a long time and its superb.

Reply
Jack Smith October 12, 2021 - 8:40 am

So, does IF make you lose muscle?

Reply
KMS Rahman October 15, 2021 - 4:11 pm

Jeff, eagerly looking forward to watching a new video on this

Reply
R Jonas October 16, 2021 - 11:02 am

I don’t even consider IF to be fasting anymore. It really is super easy and natural. Get the refined sugar and processed oils out of your diet and the foods that you’re left with leave you so satiated that eating constantly isn’t even pleasant anymore.

Reply
Nate Balls October 18, 2021 - 3:29 pm

Everyone different, You have to find what works for you, Intermittent fasting works for me. Spreading my daily carioles out through out the day or eating over 100g cards just makes me hungry all day and then I over eat and crave bad foods. when I Intermittent fast and eat low carbs I don't get hungry through out the day and my craving are for healthy foods and I have more energy.

Reply
Austin Cote October 21, 2021 - 6:59 am

I love this guy but, This video hasn't aged well… Intermittent Fasting has been studied extensively over the last 7 years. It's definitely not a fad and is much more inline with our genetics and evolutionary ancestors. When you're not wasting energy on digestion your body can divert resources to other areas at the cellular level.

Reply
Ezequiel Sandoval October 29, 2021 - 1:13 am

Great advice 👍

Reply
Dialectix Emcee November 7, 2021 - 3:03 pm

IF and keto over 3 years – the idea that these are "hard" is the fad

Reply
Optikjoe November 14, 2021 - 5:27 pm

you can be more of a human than i am :D…made me laugh…but great vid

Reply
Laura McInerney November 26, 2021 - 9:44 pm

Intermittent fasting was just normal before we had refrigerators and stored food. It makes sense. We had to wake up and go hunt/gather food, basically working out fasted. This fasted state gave hunters laser focus. Then we'd eat after getting back and cooking the food. Breakfast is a modern day luxury, as are snacks

Reply
AZFK November 29, 2021 - 11:06 pm

Jeff is really strong because instead of bones or internal organs he just has more muscles

Reply
Peter Jeffery December 3, 2021 - 5:43 pm

This video needs to be updated. I'm not discounting the basic premise but there is a TON of new data available on YT RE intermittent fasting quoting recent studies that indicate fat is burned by intermittent fasting, not muscle.

Reply
R Fow December 12, 2021 - 10:35 am

As an overweight person I want to know if 'dieting' to get to a starting weight is a better idea before implementing a life time healthy way of eating.

Reply
Lient ForJuve December 14, 2021 - 10:20 am

Human does IF for millions years already. In Hunting period, people eat once every 2 days. In agricultural period, human eat 2 times a day. On 1960++ human start to adopt 3 times per day. In 1990+++, human start to eat 3 times per day, and adding snack and adding coffee/tea with sugar between the meal.

Now 18/6 we called it fasting, in the old day, human called it a luxury lifestyle.

Reply
Chris F December 14, 2021 - 3:01 pm

Personally I'd like a follow-up on intermittent fasting and gaining muscle. I can gain muscle by eating frequent meals but my blood sugar levels end up being higher than I'd like.

Reply
giorgi chochia December 18, 2021 - 6:30 am

When you go to Intermittent fasting you will no want to go back. I'm on OMAD and feel great.

Reply