Muscle Loss and Dieting: It’s a Real Concern After All!

by · June 17, 2013

Recently I’ve read a bunch of articles from fitness experts that say that losing muscle from dieting is actually quite difficult and mostly overblown.  As a guy who fights to obtain every small ounce of muscle gain- an ectomorph if you will- I found that to be quite a relief!   Last year when dieting/cutting in the spring I lost a lot of mass, and wasn’t sure if it was truly all bodyfat or if that was actual hard-earned muscle.  In my own mind, I figured as long as I wasn’t losing strength in the heavy lifts, I probably was not losing muscle and figured all was OK.  But my wife thought otherwise, to the point where she discouraged me from cutting again this year.  Her comments were ‘you’ll lose too much muscle’ and ‘I don’t like you skinny’ when I told her in late February I was going to start cutting again on March 1st.

But this year is different- I now have the ability to measure my muscle thickness and BodyFat via ultrasound and can see for myself what is actually happening, adjusting along the way as needed. So I set off on controlled dieting while monitoring my bodyfat and muscle mass on March 1st as planned, assuring my wife I wouldn’t be letting myself lose any muscle..

I am a data nerd, so tracking calories is something I enjoy doing daily year round using my HanDBase app and a database I created that measures macro ratios and calories.  I also track body measurements via another database but only do that a few times a year.  I did a baseline bodyfat measurement on March 1st and was 14.3%.  I was happy I didn’t let myself cross the 15% mark but set a goal to get to 8%.  At 171 lbs, I was going to need to lose 13 lbs of fat to get to that goal and hence wind up at 158 lbs in an ideal world.   Not too hard for an ectomorph to lose I thought as long as I could hold on to the muscle gains I achieved.

I measured my arms at this point as well.  When I started working out about 2.5 years ago, my arms were a paltry 12″ flexed and definitely something I was not proud of.   Even when I started making some gains, my arms always feel like they are lagging behind and just last summer measured at 14.2″- a good improvement from the beginning, but no where I wanted to be.  This March, however, I was up to 15.3″ and the they were finally starting to look proportional to the rest of my physique.  Still a ways to go to be where I’d like them, but I’m proud of the progress I was able to have this winter.  And so began my dieting.

Here is a chart of my progress in weight and bodyfat measurements:

My progress from March through June.

My progress from March through June.

As you can see I reached my target weight of 158 lbs at the end of May, right where I wanted to be.  Unfortunately my bodyfat, while definitely decreased, did not reach the goal.  I now weigh the target weight but am still at 10% bodyfat.  A vast improvement over the 14.3%, and not too fat for a 42 year old guy, but still- what did I lose in place of the last few pounds of bodyfat?  Now normally with a traditional caliper method or even an underwater weigh-in, I’d have to guess as to what that is, but with Ultrasound I can actually see for myself what was lost!

I decided to measure my biceps periodically along the way.  They are not part of the normal bodyfat calculation but as a weak spot on me it’s an area of interest, and the last place I’d want to lose muscle mass 😉  My arm’s circumference measurement would decrease as I lost bodyfat or muscle, so I’d like to know which I was losing.

So how did it go?  For the first month and a half, things were going fine.  My arms lost an overall 0.25″ in measurement but if you look at my actual scans you’ll see why that was:


Ultrasound scan of the Bicep region

Ultrasound scan of the Bicep region

A few important notes
– I didn’t do a great job of tracking the lines in either measurement.  The software I use tries to find a line along the white areas and gives me the ability to click and fine tune, but in the case of the 4/23 scan at right, I did a good job of readjusting the bottom line but missed one small area along the top line.  And on the left side, I didn’t do a great job of tracing the bottom curve- could have followed the natural curvature of the muscle towards the right a little better.  But the raw data and trends are still quite useful nonetheless!

First, an overview of what you’re looking at- the scan along the left was taken on March 1st, 2013 and the one on the right was taken April 23rd, 2013.  The white areas you see are reflections off of either the muscle fascia, bone, or other variations in densities within the muscle (intramuscular fat for example).  The top edge of the image is the dermis layer and the first black area is the layer of bodyfat before the beginning of the muscle.  You can see in image to the left the average body fat thickness ranged from 2.4mm along the left to 4.3mm along the right, and in the image to the right, the range is from 1.9mm to 3.3mm.

So there was definitely a decrease in bodyfat on my arm to go with the weight loss.   How about the muscle thickness?  That’s the second measurement running from the beginning of the muscle fascia to the humerus bone.  Well, at least along the measurements to the left, you’ll see they stayed pretty steady, no accountable loss at all.  The right side is another story but that’s due to the above – I didn’t track the edge of the muscle/bone interface well on the scan to the left so the actual numbers are not very useful or accurate.  But mostly you can see the muscle was intact throughout this weight loss.

You may be wondering how much difference a millimeter of mass means to the actual arm.  It’s hard to know for sure since the bicep is just part of the arm, with the bone and triceps making up 2/3 of the arm thickness).  But if you make a simple assumption that the arm is a circle and that the fat loss was equal all around, using the old πr^2 formula, we can see that a 1-1.5mm loss in bodyfat thickness could net an 1/8th to 1/3rd of an inch of circumference.  Seemed to match my results pretty spot-on.

Thus my first 6 or 7 lbs lost were quite successful.  Now how about the second half of the weight loss?  How did things progress there?

Unfortunately not so well from the arm thickness standpoint.  By the end of May my arm measurement was back around 14.4″ – almost exactly where I was back last summer :(

So was this all bodyfat or was there now some muscle loss.  See for yourself:

Biceps bodyfat and muscle measurement via ultrasound

Biceps bodyfat and muscle measurement via ultrasound

As you can see from these measurements, my bodyfat did decrease a bit more (almost 1mm as an average).  But the big takeaway in this scan is the muscle loss.  It averages above 2mm in most places across the board.  2mm in a thickness measurement equates to a half of an inch of measurement in my arm circumference measurement.

Add up the initial loss of bodyfat with the loss of bodyfat and muscle in the second half, and you’ll see about an inch of circumference loss, which matches my results almost perfectly.

I have mixed feelings on all of this- obviously I’m not happy to have lost an inch off my arms, that is bad news for any guy wanting to put on some muscle!  But I have to admit I’m happy to be able to know what is going on under that skin and have the ability to analyze what I did differently and avoid this next time.

In particular, since I also track my calories, I can see what happened along the way with my nutrition.  My normal maintenance calories are around 2300 for the day and it’s give or take 100-200 depending on my activity level for the day, for example if I lift or run, etc.  For March and the first part of April, I averaged between 1900 and 2000 calories for the day.  About a 300-400 drop from my maintenance.  I was doing 2 days cardio a week, mostly just running once a week and the other was the HIIT variety for about 20-25 minutes.  It ranged from hill sprints to simulating hills on an elliptical or stationary bike with 20 seconds at full intensity and 40 seconds at a recovery pace.

The second half of the diet I went a little more aggressive on the caloric deficit- ranging from 1700-2000 with most days being about 1750.  I also added an additional day of cardio.

Clearly what I did was too much for me to continue burning just fat, and I started to sacrifice muscle in the process.  Does that mean a 400-500 deficit for you will mean muscle loss?  Hard to say!  I can’t even extrapolate that this will be the case for me, but I do know that next time I will try to stick with a 1900-2100 range for calories and see how that goes.  I will definitely be measuring my biceps more than once every 6 weeks.  And I will be happy to be able to share these results with you at that time.

If you are interested in tracking your fat loss or muscle building goals, I strongly stand behind ultrasound measurement as a way to do so effectively, and I’d love to be able to assist you in keeping you headed in the right direction.  Please check out my BodyFat Testing link for more info on setting something up for you or your clients.