Does muscle actually weigh more than fat?

Taking a closer look at the science behind the sentiment that literally drives me nuts every time someone says it.

CW: This newsletter discusses the topic of mental health surrounding weight and the number on the scale. If this topic makes you uncomfortable, feel free to skip.

So I guess I’m a runner now. Yes, I wrote about it in a previous newsletter, but I thought I would update all of you and let you know that I am in fact still running (ran my first 5K in 10 years last week) and I’m currently training for a five-mile turkey trot this November. Pray for me.

Anywho, as a previous dieter in recovery, I of course assume that because I’ve been running more, I must be losing weight. My clothes are fitting better and I feel absolutely incredible, so it would only make sense that I’ve also shed a few pounds…right?

Ha, wrong. When I got on the scale recently, I found myself staring at the largest number I’ve ever seen for my body.

I revolted. I cried and vented and vowed to stop eating carbohydrates because “that must be the problem” and literally started planning to diet again. All because of this previous notion (steeped in diet culture lies, may I add) that if I become a runner, I’ll also shed some pounds.

Angry and hurt, I turned to some of my closest people and told them what was going on, and it’s kind of comical how many people told me the following sentence I have heard countless times in the past:

“Muscle weighs more than fat.”

Let me tell you, dear reader. When you are a curvy girl like myself, this type of encouraging sentiment doesn’t exactly land and doesn’t make me feel better. I know people say it to me with the best intentions, especially given how much I run and lift weights and go to yoga these days. But it doesn’t change how I feel.

Feeling a bit over-emotional about this particular saying, I decided to do some research. Clearly, the saying comes from somewhere, but we all know that these tidbits of “advice” may not always be true. For example, the saying “breakfast is the most important meal of the day” was actually coined by a cereal company to get you to buy their product…and now many people take it as actual nutritional advice for their health.

So does the same go for muscle weighing more than fat?

Muscle is, in fact, denser than fat.

Here’s the truth—if you were to compare the volume of muscle versus fat, then yes. Fat by volume is actually a lot lighter than muscle, which is leaner; five pounds of fat looks much larger than five pounds of dense muscle. So if you were to have a muscle with the same exact circumference as fat, then the muscle would weigh more.

So yes, it is possible to slim out and still gain weight.

Especially if you work out. When you exercise, your body stores glycogen, a form of glucose that helps to regulate your blood sugar. The glycogen binds with water, which means you may have some extra water weight on you as well.

When exercising, the body also undergoes some inflammation. Exercise puts strain on your muscle fibers, causing micro-tears. While this process is what helps muscle strength to grow, delayed onset muscle soreness (DOMS)—aka, when your body feels that oh-so-good-soreness the day after a workout—is a sign of the body undergoing inflammation and the muscle recovery process.

After learning this, I realized that my clothes fit better and I’m gaining weight, and that’s completely normal. Workouts can cause weight gain via building muscle and other factors related to exercise, but I’ll also slim out because of the circumference difference between fat and muscle.

The scale doesn’t tell the story.

I mean I should know this one by now, right? The number on the scale doesn’t show me the entire scope of what’s going on in my body. Yes, I will always hold a little bit of extra weight in my hips and thighs—that’s simply genetics.

But because muscle is denser than fat by volume, I can feel comfortable in my clothes and still be gaining weight. The body is so much more complicated than calories out and calories in, and even if you are consistently running again, that does not guarantee you’ll be just as tiny as you were in high school or college. You live in a different body now.

Maybe that’s the sentiment I need to hear next time I have a freak out about a previous diet culture lie that is poisoning my thoughts.

“Your body is different now.”

And that is such a beautiful thing.