Does Intermittent Fasting KILL MUSCLE? (Diet Confusion)

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

  • Common sense flying in the face of fad diets

  • I don't see intermittent fasting as the magic bullet to lose weight. I use it as a tool for when I am about to go on my cheat days. And I do it every other week. I've been consistent about it as well.

  • I do IF and I love it. I have an 8 hour window and I don´t eat junk food. I stiil watch what I eat. IF is for free, not a diet.

  • IF has helped me more than anything I've ever tried. I did my research and IF made sense to me. Every body is different; IF works for my body. 🙂

  • Question…how you ever been fat?

  • The Ketogenic lifestyle is not a diet. I know people who have been on it over 2 decades.

  • Twice In a week IF is good makes me happy

  • Hundreds of people already said this but IF isn't a diet or a fad. It's great I've lost 10 pounds and I just started.

  • Kinobody has been on a intermitting fasting diet for years now and he is lean and buff. Any diet works if it fits you. Many people don't even like to eat break fast so just chug some green tea and start eating at lunch time. This is what many people do anyway. How is this a problem? You sound very close minded. And you do not have 4-5% body fat dude. I thought you're legit but I think you're bullshitting people to sell your programs. Rofl 4% body fat without any health consequenes…yea right 😀

  • I would like to see Jeff re-attack this in a newer video. I find intermittent fasting sustainable and very useful. I also find I still keep putting on muscle – but I am also the sort to eat a shit ton and also easily gain muscle.

  • Lovely Video clip! Forgive me for the intrusion, I would appreciate your opinion. Have you tried – Dinanlinson Amazing Look Approach (just google it)? It is a smashing one of a kind product for learning how to quickly lose weight without the headache. Ive heard some incredible things about it and my mate at last got cool results with it.

  • Can you tell me: do vitamins break your fast? Do they trigger you insulin or not? Or does it depend on the supplement?

  • Yes there are peoples who fast every Mondays and Thursday s for more than 30 years in top of that every year they fast for one month from sunrise til sunset. Those people are a Muslims

  • I had never realized the power of diet until watching Jeff. In 6 days time I lost 8lbs by following his diet and working out 30 minutes per day. This guy is one of the most legitimate voices in the world of training. A physical therapist and a personal trainer =legitimacy.

  • I don't think you ever answered the question does intermittent fasting kill muscle at all…. the biggest problem is people schedule….. I get up at 4 in the morning to be to work at 6:30 and there's no time for nothing so I meal prep the day before have a big breakfast I get off at 3:45 or 6 I don't have time to work out and eat because I go to bed at 7:30-8…. flywheel big breakfast in about 5:30 and then eat one good meal at 11:30 or 12 and then maybe a couple of greens before I go to bed or a vinegar lemon parsley honey ginger Shake….

  • I have a question: Since I've been to the gym (around the 1st of july) and I've dropped from 76,7 KG (168,74 LBS) to 71,5 KG (157,3 LBS) with a 5,1 KG (11,22 LBS) deficit. I am 185 cm (6'07 foot) tall. Do I have to worry about acces skin, should I try to calm down with loseing weight or am I good to go? I am curious, because from the last 3 years I've been dropping from 100kg (220 LBS) to now my 157,3 LBS. Currently I can see the upper muscles of my six pack. My goal is to reach a BF of 8-12% at the beginning of the summer of 2018.
    Thanks for your reply guys 🙂

  • I stumbled into intermittent fasting by accident. I simply could not stop eating in the evening and eventually I embraced it. I now only eat in the evening. I start at around 7-8 p.m. and eat till midnight. This has been working for me for about 2 years now. I don`t foresee any difficulties with continuing to do so in the future.

  • No offense, but I used to think I had the worst eat habits as a kid, seeing this made me feel better on all levels. I'm glad you found your way as I've improved and am continuing to succeed just like you. Intermittent Fasting has done great wonders for me so far and I hope I can keep it up.

  • Sounds like an opinion

  • How about Sensible eating with intermittent dieting?

  • Intermittent fasting is pretty easy to adhere to Jeff, and it actually gets easier over time. I wouldn't call it a diet, but rather a eating strategy that can be combined with a diet to maximise results. IIFYM or keto can be used in combination with IF.

    Compared to just doing what you do Jeff which is eating a balanced diet or what you might call it… It's fairly easy to slip when their is a cake in front of you or your just cant find the food that you should eat. Just bunching all these up and specifically IF and IIFYM i think is not helpful information. IF for example is very flexible… it's an 8 hour window of eating, or you can pick a day or two in the week where you fast.

    I do enjoy most of your videos, just not this one.