How to Lose Muscle Mass

by Brad Pilon

As you can imagine, questions about Eat Stop Eat have been pouring in to my In-box, with the most common question being about fasting and losing muscle. Most people are still very concerned that they will lose muscle if they don’t eat every 3 hours. My answer has always been, don’t worry, if you are Resistance training then you won’t lose muscle.

Then I received a very interesting question that went something like this – “If calorie restriction doesn’t cause muscle loss, then what does?”

Great question. We all know that people who are bedridden and on a low calorie diet lose muscle. When I first starting writing Eat Stop Eat, and was running the idea past several dietitians for input, they all brought up stories of muscle loss in their patients who were bedridden and on a low calorie diet.

And since I am constantly saying that caloric restriction doesn’t cause you to lose muscle if you are working out, then that leaves being ‘bedridden’ (or ‘disuse’ as they say in research) as the cause of muscle loss.

Ever break your arm and have to wear a cast, or know someone who did? Do you remember how skinny that arm was when the cast finally came off? Put a cast on your arm and your muscles shrink faster then an expensive new shirt in the dryer.

There was no change in nutrition, only a change in the amount the muscles were used, and the muscle wasted away.

In fact, ‘casting’ is so effective at causing muscle loss that it has been used in research to study something called ‘disuse atrophy’ or muscle loss from lack of use.

In a study conducted at the University of Nottingham, 22 male and female studies had casts put on their right leg for two weeks. Their diets didn’t change, yet after only two weeks the cross sectional area of their quadriceps (the big muscles in your thigh) decreased by 10%.

NO change in diet..but the muscle still decreases in size by 10%.

Bottom line – as long as you are working out, and meeting some sort of caloric minimum (studies have gone as low as 80 grams of protein and 800 Kcals a day), you won’t lose muscle. However, if you don’t use the muscle, then it really doesn’t matter what you are eating, the muscle is going to shrink.

BP

PS- If, by some fluke accident you do break your arm, the research from Nottingham found that Creatine Monohydrate can speed the rehab process, helping you build back your muscle and strength quicker than normal.

Toronto Personal Trainer

{ 9 comments }

Craig Ballantyne, CSCS, MS August 25, 2007 at 4:31 pm

great info, well written

Redlefty August 25, 2007 at 7:02 pm

Fascinating as always, Brad. I’ve always loved that study that showed the 800 kcal diet’s impact.

billy August 26, 2007 at 10:40 pm

So, you’re saying that the whole “catabolism” theory that’s so popular in the bodybuilding arena, for instance, is bunk? That theory goes that during severe caloric restriction the body burns both fat and muscle for energy.

Brad Pilon August 27, 2007 at 1:54 am

That’s exactly what I’m suggesting…inactivity is what eats up muscle mass.

I have some cool info protein I’m gonna share soon that I think will compliment this info nicely.

BP

kev February 6, 2008 at 11:24 pm

This is a great post and just what I have been searching for. My body can build muscle mass even if I only have a small bowl of cereal in the morning, and a small yogurt at lunch prior to my evening heavy cardio workout. If I so much as look at weights, I will gain 2-3lbs. which is not so good when you are trying to lean out. I play lots of tennis and want to get pressure off my knees. And muscle mass is still mass, after all. So I’ve been working hard at trying to lean out.
Maybe I just need to put myself into a full body cast for a week. LOL

Jenifer February 8, 2008 at 8:19 pm

Hey Brad…I’m trying to lose muscle mass on my thighs…I want more slim and feminine thighs…any suggestions? will cardio-dance workout reduce muscle mass or will i gain? this might be a dumb question but will wrapping plastic bags around my thighs and not exercising reduce muscle? your story on “cast on arms” was interesting…thanks

Jenifer

Anonymous May 18, 2008 at 5:47 pm

Hi

I want to lose the WEIGHT that muscle build up around thighs has caused-will this happen ?

Have same problem…muscle on thighs that I cant lose- am really upset about it- have always been around 8st 2lb , started going to the gyn more for mind therapy than anything else , got put on a cardio prog of 15 mins on cross trainer,15 min bike, 30 mins treadmill & ended up putting on muscle & going up to 8st 9lb …as soon as I noticed it 3 mths ago, I come off the resistance progs -no one told me I would gain weight even tho I told the gym i did not want any muscle gain- have come off all the equip except the treadmill , 45 mins on manual to get cal burn but 3 mths on I still weigh the same, 8st 9lb instead if 8.2 Help !! I feel I have ruined my figure & my jeans all feel tight- hard life I know but help!!!

b3eautifulenigma October 22, 2008 at 7:21 pm

I know some women on here posted about leg muscle loss…which is opposite for me. I would love to be able to keep leg muscles but unfortunately my legs are leanish and I tend to lose muscle in that area first. Anyway, I built way too much muscle in my deltoids the muscle covering over my shoulder. My body is kind of naturally boyish and not “wide” so being female and having built this shoulder muscle looks horrible. I’m so glad Brad was able to help to state that low calorie intake plus inactivity will help eat up hard earned muscle. I always thought that running could help lose muscle which it can but it requires a TON of cardio that is impossible for me to do. The most I can do is 3 to 10 miles but not running or jogging the whole time. It hasn’t done much I think the fact that my calorie intake is low that did the trick. But being inactive is the best because the muscles arent being used and will be eaten up over the inactivity time and I will be doing a lot more sleeping than I normally do..that will definitely help.

Thanks Brad!

Christina October 22, 2008 at 7:22 pm

I know some women on here posted about leg muscle loss…which is opposite for me. I would love to be able to keep leg muscles but unfortunately my legs are leanish and I tend to lose muscle in that area first. Anyway, I built way too much muscle in my deltoids the muscle covering over my shoulder. My body is kind of naturally boyish and not “wide” so being female and having built this shoulder muscle looks horrible. I’m so glad Brad was able to help to state that low calorie intake plus inactivity will help eat up hard earned muscle. I always thought that running could help lose muscle which it can but it requires a TON of cardio that is impossible for me to do. The most I can do is 3 to 10 miles but not running or jogging the whole time. It hasn’t done much I think the fact that my calorie intake is low that did the trick. But being inactive is the best because the muscles arent being used and will be eaten up over the inactivity time and I will be doing a lot more sleeping than I normally do..that will definitely help.

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