How To Lose Muscle While Dieting

By JC Deen



Learning how to lose muscle while dieting is probably easier than you think. No, really.

All you have to do is train too much and eat too little.

Read on to see exactly what I mean.

I remember the first time I dieted down… It was my freshman year in college, and there was a bet between me and 15 other guys to see who could get the leanest.

First, second, and third place winners would walk away with some cash. I was sold. Show me the money.

The Best Way To Lose Muscle

Most all of us were up for the challenge. We all began training 4-5 days per week with lots of cardio.

Now at the time, I was 19 and could withstand much more mental and physical stress because I was in college, had no job or obligations outside of my studies. Food was taken care of at the mess hall, and I only needed to worry about what I’d be doing on the weekends for fun.

I lost about 30 pounds during a 16 week period but along with a lot of fat, I also lost a good amount of muscle.

I know this for two reasons:

  • I lost a good amount of strength on my major lifts (more than 10% reduction in total loads).
  • I lost a good amount of size in my upper body and noticed it considerably in how my clothes fit.

My training was comprised of 4-5 days of weight training, and 6 days of cardio. Here’s a sample schedule:

Before Class: 45 minutes to an hour of fasted cardio on the treadmill/elliptical

Breakfast: Lots of egg whites (1-2 yolks) and oatmeal

More Cardio: Lots of walking between classes and the cafeteria (I was eating 5-6 times per day)

After Class: Hit the gym and do a high rep body part split (not optimal)

Dinner: no carbs after 7 pm, because I thought it’d make me fat

Bedtime: never at a decent hour (then wake up and do it all over again)

While my diet was probably high enough in protein to prevent major muscle loss, my deficit was pretty big due to the activity, and I didn’t rest as much as I could.

When this happens, stress hormones are HIGH. Things like cortisol and adrenaline will spike and the healthy hormones like thyroid (T3, T4) and testosterone will plummet.

I found myself irritable, tired, and frustrated a lot, but I had a goal.

I wanted to get lean for the first time in my life and win this contest.

First of all, I was doing way too much training volume for the amount of food I was eating.

My training sessions were longer than an hour each day, and exhaustion was high. I’d fall asleep in class often and sometimes miss due to just staying in my dorm.

My overall training loads was over 15 hours per week if you count the cardio and weight training sessions.

Learning How To Lose Muscle Netted Me 300 Bucks

In about 16 weeks, I lost 30 pounds (both fat and muscle), got 2nd place in the best body competition and was PUMPED about my results.

However, it wasn’t the best way to go about losing body fat at all. It cost me strength gains, muscle gains, and I built up a lot of neuroses about food and training.

It took me a good few years to snap out of all this behavior because I was afraid I’d lose my abs, and get fat again.

But I learned a lot in this process: mostly how not to go about losing fat, and I learned a lot about how to lose muscle on a diet.

I also learned how to run for long distances (many times over 5 miles a session). I actually hated running, but thought it was the only way to lose body fat.

About a year later, I eventually found a mentor who took over my training and diet-related activities and coached me to a bigger, thicker version of myself.

How To Lose Muscle Checklist:

  • Drop your protein intake to third-world levels. Less than 30g per day should work wonders.
  • Increase your cardio training output to running for long distances every day.
  • Sleep less than 8 hours per night.
  • Fast for long periods of time (alternate day fasts would work wonders here).
  • Weight train with a TON of volume — much like what you’ll find in the bodybuilding magazines.
  • Always push your training to failure, and exhaust your nervous system.

WARNING: You Don’t Really Want To Lose Muscle

Here’s why.

  • Muscle tissue is metabolically active, meaning it burns more calories at rest.
  • Muscle tissue is protective of your joints, internal organs and other tissues.
  • Muscle helps you maintain better posture.
  • Muscle gives your body shape, and to many people, is more aesthetically appealing.

If you purposefully lose muscle through hard dieting and training, you can cause your body more stress than necessary, and even hurt your thyroid (master hormone that affects metabolism).

Instead of trying to purposefully lose muscle, it’s better to aim to lose body fat through proper diet and training methods.

  • No starvation diets.
  • No overly excessive training schedules that zap your energy.
  • No unsafe supplements or fad diets that hurt your body.

Here’s what you could do instead.

Learn how to train properly for fat loss. You can check out which workout plan is right for you.

If you have questions about fat loss, we’ve answered a lot of those questions in this article: how to lose weight.

Remember to make sure you eat well to fuel your training. This pre-workout meal guide can help.

And lastly… learn the truth about the best exercise to lose weight.


38 thoughts on “How To Lose Muscle While Dieting”

  1. Hi i want to loose muscle is running okay and ive stop doing body pump got alot of muscle in legs and chest.

  2. Hi there. You mention skimping on protein to drop muscle. Can you please define “skimping”. I need to drop some bulk for distance running, yet I assume I still need some protein in order not to break down. Can you suggest grams per pound of body weight of protein required in order to address both of my goals? Also…how much of a daily total calorie deficit would you suggest?

    • I can’t really give you an *exact* amount. If I personally were trying to lose muscle, I’d stop training, and eat like .5xbw in protein.

  3. I’m interesting in losing my legs muscles from running track. I’m a sprinter so I bult a lot of strength on my thighs… I really want to lose it though because it make me feel uneasy… I know that’s bad bc I should be happy as I am right now,.. But I want to lose those muscles and I won’t do track anymore…as you suggest to skimp down proteins and do a lot of cardio but my question is that does cardio will still build my muscular legs/thighs? I heard no matter what exercise you do you’ll build more muscles… I really Ned your help … I’m about 5’3 120 I’m not fat. I used to be 102 before track so I believe more than 15 lbs is my muscles…

    • long, slow cardio like walking is not going to build your legs up. also, if you’re not eating much protein, it will be hard to maintain that muscle. staying away from heavy impact lower body work should make sure you lose size in your legs.

  4. Hi JC,

    I’m very much interested in losing muscle/size. I weigh about 13 stone and I’m 5’6′ and have a typical Celtic (I’m Scottish) build (short and stocky).

    I get the cardio thing but can you elaborate more on the diet? You know, breakfast, lunch, dinner ideas and options?

    Thanks in advance, Will

  5. Hi, I’m so glad I found this website, I’ve recently put fat and muscle on with going back to work full time after maternity leave, desk job see… So I need to loose weight/ muscle on my legs thighs and bum, I don’t do any gym work don’t have tone with being a single mum, but I’m looking to join a gym next mont now I have a friend to babysit, my question is I don’t eat lots of protein as it is, so is it the carbs that’s making me put weight on? I’ve been trying to stick to 1200 cals but actually seem to be putting more weight on :/ I need help here, do I cut out all carbs? Or most carbs? To loose this weight first then concentrate on loosing muscle?

    • this article was not intended to be a guide on *losing* muscle. If you’re eating 1200 kcals daily and not losing weight, something else is wrong. I’d up your protein and cut out some carbs, but it’s hard to really say without knowing more information

  6. I can relate to this, I wanted to get extra lean so I stopped weights hit cardio 200%, reduced my intake to less than 1000 calories a day and ended up looking emaciated. I couldn’t see it but everyone knew kept telling me not to lose anymore weight. I look back at the few photos I have of then and cringe. They aren’t pretty but I earnt a valuable lesson, I would rather have sexy bigger muscles than look like a Praying Mantis with twig arms and legs.
    Bring on the weights, the protein, the dairy, the good fats and days of rest with a little cardio thrown in on top ;)

  7. So I am sitting here at 0230 hours simply because I thought “Oh yeah, I’ll check my muscle mass!” I checked it and was horrified that in the last 52 days since checking I had lost 1% of lean muscle mass and GAINED 1% of body fat this is in spite of walking upwards of 6.5 miles a day and having lost 10kgs (22lbs)…So found this website and have discovered that I’m not the only foolish one to have done this…So what I’m gathering thus far is that I need more protein, more weight-bearing exercises and not to be so strict on the calorie intake…Thanks a heap, would love to see the second installment on how to add lean muscle mass while exercising! Thanks again!

    • hey Jeff – what methods were you using to measure these changes? Those are pretty small differences and I’m curious as to if it might be the shifting of water or something else that might skew your results.

      Have you maintained your strength during the diet?

  8. so im a really built guy i powerlifted in college…but i wanna go military so i want to lean up i have to much muscle and a little fat too loose whats the best way of doing this?

    • eat in a deficit, do lots of aerobic work (running, jogging, biking, etc.) and don’t lift as heavy.

    • My apologies for missing this one. When I was referring to volume, I meant the volume of training. Thusly, if you do 10×10, you’re doing a lot of volume. of you do 2×5, that’s low volume.

  9. you said you ate 5-6 times per day..
    what kind of food did you eat? and how much of it?
    i’m actually trying to lose fat AND muscle at the sametime.

  10. HAH! I used to over exercize to the point of that I lost 50 pounds in two months! but it turned into some serious eating disorder anorexia nervosa and bulimia. I see myself as big and I got scared to eat. I litteraly starved myself at 135 pounds. I didn’t eat anything except drink water. I was 80 pounds at height of 5’7 and almost died…I had edema too… icky stuff. I gained back what I lost when I first became a bulimic before anorexia nervosa hit home. Good thing is I am able to lose weight and am working on this with a nutritionist to get to my goal weight of 127 pounds because I gained up to 157 which wasn’t too bad. I’m glad my body realized it wasn’t starving anymore and decided to start breaking down calories instead of storing more. I consider this a blessing. I’m thankful! So you bet I lost a ton of muscle! Since I’ve been eating I gained the building blocks of muscle aka protein..but not muscle itself. Everyone would look like arnold s. if we all ate protein and bulked up. But yeah I’ve been through this. Glad you shared soemthing like this from a males point of view. It’s quite interesting because for girls stuff like this can be really bad. Take it from me. Glad you’re doing well! So it seems.

    • thanks for sharing Christina. I knew a girl my first year of college who became really skinny due to bulimia. eating disorders are nothing to mess with and I’m glad you are getting help from a nutritionist.

  11. Wow, you guys were serious way back in college, huh! “bro split” lol!

    The bottom line is – you got results despite the tons of mistakes – because of your shotgun approach. It sure is possible to get those results with a tad less effort.

  12. Good stuff JC. I like how you mentioned that you even walked to the bar. LOL. But, you’ve highlighted a trap that many, many, fall into. I’d say especially females, in regard to over-cardioing and under consumption of protein. It’s also unfortunately common in the fitness/figure scene, contributing to the metabolic issues so many can experience in the post-competition or post-dieting phase.

  13. You’re a great teacher, but as for ending up “half naked in a room with 15 other guys, flexing and posing in front of some dudes I have never met”, why wasn’t I invited??

  14. Very interesting story about your journey to be fit. If I’m understanding you correctly, you’re saying you lost a lot of fat and were in great shape, however, you lacked strength.

    Kinda curious. How did some of your 15 competitors in the bet fare? Did you learn anything from their experiences? Did they do the same type of training and dieting you did?

    • I did lack strength. I lost lean body mass as a result, too. When one diets and strength loss occurs, muscle loss occurs.

      Most of them did the silly crap that I did. So, no, I didn’t learn much from their experiences.

  15. @JC

    Great stuff here. Most people don’t realize protein requirements increase under hypocaloric conditions. 2g/lb, even on natural trainees, isn’t unheard of if the deficit is encroaching on 50% of maintenance caloric intake.

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JC Deen is a nationally published fitness coach and writer from Nashville, TN. Currently living in the blistering Northeast. Follow me on X/Twitter