The Truth About Muscle Loss When Dieting - FitMole

The Truth About Muscle Loss When Dieting

93 Comments | Diet

muscle loss

Muscles are like lizard tails – they can come back if you lose them.

People worry about the weirdest and most irrelevant things when dieting. When you’re dieting, your #1 goal is to lose weight (fat specifically), nothing more, nothing less. You should only be worried about how you’re going to create a calorie deficit for the day.

However minds begin to wonder, goals get distorted, and people begin coming up with these crazy “what if” scenarios.

“What if I eat less and my metabolism slows down?” – Nothing to worry about, covered that here.

“What if I lose weight but regain it all back?” – Then you’re not a very long-term minded person, are you?

“What if I go on a diet, become insanely sexy, and end up causing head-turning car collisions which in turn gets me arrested because of said sexiness and I get a life sentence in a maximum security prison?” – Completely legitimate concern, but that’s just a risk you have to be willing to take.

“What if I lose all my hard-earned muscle while dieting?” – Read the rest of the article.

Muscle loss while dieting is nothing to worry about

I completely understand people’s fear of losing muscle while dieting but the truth is that it’s nothing to worry about.

You see, muscle loss is transient. It’s not permanent. 

So even if you do somehow manage to lose 5 pounds of muscle while dieting, whether it’s due to an illness, extremely low protein intake or lack of resistance training…you’re guaranteed regain that loss once you begin eating normal and resume resistance training.

This is all thanks to muscle memory, which unlike muscle confusion, is a real thing.

Why the hell are you worried about muscle loss?

As long as you’re getting an adequate amount of protein…

As long as you’re consistently weight training while on your diet…

As long as you don’t go on any crazy crash diets….

You’re probably not going to lose any muscle mass. And even if you do manage to lose some… the amount will be minuscule.

Focus on losing body fat, because that’s the hard part. Worrying about muscle loss is just counter-productive.

Once you’re at your desired level of leanness, gaining back any lost muscle will be a relatively easy thing to do.

It’s the mindset of “Oh I should eat more food because I’ll lose muscle” that’s hurting your progress. The only thing eating more food will do is make you fat.

Saying that you should eat more while dieting is just a lame cop out for those who don’t have the discipline of consistently eating less.

Photo Credit – Nuno R.

Troy @ Formulated Fitness - August 23, 2012

I believe that you should be able to diet effectively while gaining lean muscle at the same time. As long as your diet is high in fiber, lean protein, and the RIGHT kind of carbohydrates- this is realistic. The more lean muscle mass you gain the faster your metabolism will become as well.

    Keith - August 23, 2012

    Yeah it’s possible but gaining muscle and losing fat typically doesn’t happen unless the person is a complete beginner

      Michael Franco - May 6, 2015

      I’m a complete beginner and I’m having a really hard time losing the fat I have left and gaining muscle at the same time. Any tips ?

        Keith - May 6, 2015

        that’s why you should only focus on one at the time, not both.

Marjorie - August 26, 2012

You build up your muscle mass by exercise and eating protein rich food don’t you? If you just starve yourself to death then of course you’ll only get to be skin and bones. Muscles are not like fat that get built when you eat fatty foods. Muscles need tending. 🙂

Kim - August 28, 2012

Nice post. But there’s one question I don’t seem to find the answer to: See, I’ve been working out for a little over three months now. I was following a well structured plan that included weight lifting and a little cardio (20 min high intesity per session) as well as a diet plan which is pretty similar to everything you say about eating (creating a calorie deficit ect.). When I started, I wasn’t trained or in any shape (e.g. able to do two pull ups max and no muscle definition at all). I was kinda chubby. The point is… even though I’ve lost a really viewable amount of fat I didn’t seem to put on any viewable muscle mass at all. My arms are thin as they can be, my chest is kinda skinny (which is still better than the man boobs i had before…but no trained look at all) and still there’s this annoying rest of fat round my hips which is giving me the impression to look even worse in combination with the skinny arms, shoulders and chest. I know three months of training are nothing. But shouldn’t there be any viewable results when it comes to muscle mass? My question is: Since you’ve been talking a lot about reducing body fat to make the muscles pop out by following a nutrition which creates a calorie deficit…is it the right way to follow that plan and continue working out when I actually want to put on muscle mass? I mean, shouldn’t I be building a caloric surplus when I want to gain muscle (and therefore weight)?? I’m sorry if this bothers you. I’m sure you get questions like this every day and there’s an easy answer to that. But everywhere you look, there are different opinions and I’m really confused right now?!

Anyway… I’m taking a huge benefit from your posts (especially when it comes to motivation). Thanks for that.


    Keith - August 31, 2012

    Hey Kim,

    Your muscles can only “pop” if you have the muscles in the first place. From what you told me, it seems like you lost the weight but don’t have much muscle underneath.

    So now that you lost the fat, your goal should be gain muscle. So that means going on a well-structured muscle building program and eating in a slight caloric surplus. If you want to minimize fat gains, only overeat by 300-500 calories on your training days and eat at your maintenance calories on your rest days.

    Hope this helps.

Jeff Strongman - July 8, 2014

So say I do the 800-calorie plan for 5 days straight for about half my protein (at best) intake for that time BUT I continue lifting, appropriate rest. The muscle loss will be miniscule?

    Keith - July 8, 2014

    Shouldn’t be too bad, but you should always aim for high protein when going really low calorie.

Frank - September 19, 2014

Hey Keith, great article. I have a question regarding this. In 2008, I went from 367 to 240 in about 7 months with lifestyle modifications. When I was at my heaviest, I had a good foundation of muscle as I lifted for at least 10 years prior. I gained all the weight back the next year, and during the next 5 years, I have lost 60 pounds or more on 5 separate occasions; I did lift during each “cut.” I eventually got up to 395 pounds, and 4 months in, I’m down to 320 pounds, but I have not lifted at all. Do you think most of the muscle I had when I first started back in 2008 is still there, even with all the weight loss cuts over the years? Also, if someone loses muscle due low protein intake, will muscle memory kick in once they consume enough protein? Thanks for your time.

    Keith - September 19, 2014

    Yes there is muscle memory so you will regain once you start training hard again. You won’t regain your muscle simply with a high protein intake, you need to lift weights like you did before as well.

rene - November 22, 2014

ive been dieting and body weight training for a year now so all of a sudden i lose a lot of muscle, i still have the size but im not as strong. i cant even carry a gallon of milk without dropping it. any help?

    Keith - November 23, 2014

    it’s because you’re not lifting weights. Start lifting weights.

Rainhart - November 25, 2014

Hey keith, how much calories and protein i must gain in a day if i am on a diet, but i dont want to lose any of my muscle?

    Keith - November 25, 2014

    cals = 12 x BW in pounds
    protein (in grams) = 0.7 x BW in pounds

      Reinhart - November 27, 2014

      Can cardio burn my muscle mass, if i’m on a diet?
      Is it good to do cardio during the diet or not?

        Keith - November 27, 2014

        no it won’t directly burn muscle.

        I don’t recommend cardio until you need to get really lean (sub 10% for guys). Focus on your diet for fat loss first.

          Reinhart - November 28, 2014

          You said it isn’t possible to gain muscle instead of losing fat, what if i eat a lot of protein? Is it possible to gain muscle instead of losing fat?
          Or maybe i should gain muscle first then losing fat?

          Keith - November 28, 2014

          Your question was about cardio but I never said it wasn’t possible to gain muscle. It is very possible, you just shouldn’t do a ton of cardio when your main focus is muscle building.

          I don’t know your starting point, if you want email me a pic of your physique at and I can give a quick look.

Richard Gonzalez - December 3, 2014

Hey. I really enjoyed this article. I have a question. I’m on a very low calorie diet so I bought a protein supplement to make up for the protein I’m not getting, I made the mistake of getting a protein powder that especially for BUILDING MUSCLE. How would this affect my diet? Would it make me gain weight like I’ve heard? I’m not trying to build musicle yet just want to maintain it and lose fat, Thanks.

    Keith - December 3, 2014

    i just stick with regular whey isolate. Protein powder isn’t special, it’s just an easy way to get protein in your diet.

keekee - January 26, 2015

I had the gastric bypass surgery I have lost a lot of weight and I also have lost a lot of muscles mass what do I need to do to gain my muscles back and to also take in a lot of protein

Dawn - February 12, 2015

If I’m eating 1000-1200 calories a day to lose 40 pounds by July will this make me lose muscle?? My BMR is 1400

    Keith - February 12, 2015

    depending on how much you weigh, but for most that’s too low.

Mel - February 25, 2015

Thanks for the article. A couple of years ago I actually experienced this issue that you are downplaying here. I wonder if age and gender might be a variable that you haven’t considered. Two years ago (at 44) I was on a Crossfit regimen along with martial arts and running.. Yes, I leaned-up very well — better than ever in my life. I ate a fairly low calorie diet as well. I reached a point in my fitness advancement where I could not seem to build more muscle and strength (and I wasn’t very big). I was lean, but I was also sore most of the time and never could seem to “recover” and rebuild.
After a new baby in 2013, I am working my way back to that level of fitness and looking for the right mix of diet and nutrients because I do believe that this must be the key. I know we can’t be 20 again and recover like we did from a workout. Any ideas about the right mix of protein and calories, etc. that can help?

    Keith - February 25, 2015

    for protein I recommend at least 0.7 grams per pound of bodyweight.

    Calorie wise, it depends on your goal. For weight lose 10-12x your bodyweight is a pretty good goal. Use 10 for a few weeks if you want to expedite fat loss a bit.

Don Bodenbach - March 1, 2015

Honestly none of that really matters in terms of losing fat. All that matters is that at the end of the day , there is a deficit in calories.

Carson - May 19, 2015

Great article kind of what i had been searching th internet for.

Most of the articles talk about muscle memory and making rebound muslce gains quickly in the case if you had *stopped* training and lost muscle.

So just to be clear with your article you are stating that regaining muscle is a quicker and easier process if for say i went on a long Cut and lost a bunch of muscle (15 pounds :(….quicker and easier than building new muscle for the first time??

I figured that was the truth because so many hollywood actors do this all the time (robert downey 20lbs 12 weeks gain—-Christian Bale 60 lbs in 6 months)

Thanks for any answers Great article.

    Keith - May 19, 2015

    Yes regaining is much MUCH quicker.

    Yup that’s the dirty truth in Hollywood pretty much no one talks about. When you hear about guys especially guys like Christian Bale who transforms his body pretty much every movie, the reason he can gain weight so fast is because he loses it but already has the “muscle memory” and his foundation is already built so rebuilding it is much quicker.

    It’s rarely 20-30 pounds of brand new muscle, it’s muscle the actors already had.

      Carson - May 19, 2015

      Thank god i say! lol

      Thanks for replying.

      I read somewhere that it is the muscle nuclei shrinking but not actually ever dieing off or leaving.
      I found this interesting since its the same thing as fat cells…you can shrink fat cell but you can never actually get rid of them and you can creat new ones.

      So my concluision is that fat and muscle are actually somewhat similar…in the way they behave.

        Mark - July 14, 2015

        Look into the Military study done by Karl Friedl. Even when they pushed the limits of these already somewhat ripped military dudes to their limit, it wasn’t until 6 weeks into it, that they were really starting to lose any muscle mass, even though they ate only 1,000 calories and did crazy exercises which burned 6,000 calories per day. They also made the soldiers sleep deprived. They wanted to see how far they could push these guys before they started losing muscle mass. Brad Pilon of Eat, Stop, Eat, was the one who I heard speak on that. Don’t worry about losing muscle even if you’re aggressively cutting calories. If you have 15% body fat or higher, your body is going to tap into that first. Your muscle losses will be miniscule according to the study done by Karl Friedl.

          Dax Carver - August 2, 2015

          Do you have a link to this study? Did Friedl have them train with weights or just cardio? Thanks!

Chris - June 13, 2015

Hello i have 1 question for you that I was hoping you would help me with. i am female
i used to lift wieghts a lot, and do a lot of training for about 3 years I was really good shape.
Unfortunitly I had a horrendias injury, and I was only able to do basic things in life and no training for the past 8 months……. I also was havinig huge money problems so i havent been able to eat much either…
Things are starting to look better and I maybe able to start training again, although i feel I barely have any strength or muscles at all….. anwyays im so discouraged becauce all the muslce I had appears to be gone, I have also lost a lot of weight in this time…. maybe 12 pounds, but I was only 132 before…
Will my muscle come back quickly? or will it take a long long time?
Is there really such a thing as muscle memory, even when it appears you lost all the muscle…

    Keith - June 13, 2015

    yes muscle memory is very real.

    While you may feel weak now, you’ll regain you’re strength much quicker than it initially took you, assuming you’re able to to perform exercises with the same range of motion as before.

rushZ - September 9, 2015

I have lost considerable belly fat and appear more to be slimmer both by controlled diets and working out for 30-45mins a day for 6 days/week. i would like to know how i could build mass now and get the muscles pop out.

    Keith - September 9, 2015

    you need to start lifting weights, get progressively stronger and eat more.


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