Why Are Overweight People So Muscular?

Illustration of an Overweight Person

As a skinny guy, I always wondered why overweight people were so much stronger than I was, especially in their lower bodies. I mean, I didn’t exercise and neither did they. I didn’t eat well, neither did they. Where was all that extra muscle coming from?

I understood how they had become overweight. I knew I had a small stomach, a meagre appetite, and a fast metabolism. My high metabolism was obvious to everyone who knew me—I was always fidgeting, always moving, always radiating heat. I was a classic ectomorph.

What I didn’t understand was how much muscle overweight people were gaining simply because they were overeating.

One of my university roommates, Willem, was a muscular guy who naturally weighed in at a hearty 200 pounds. Over the course of a couple years, he managed to lose twenty pounds by doing P90x and 5-minute ab workouts in our living room. It wasn’t enough to preserve all of his muscle as he lost weight, but he had muscle to spare, and so he still wound up looking pretty buff by the end of it.

Here’s Willem’s weight loss photo next to one of my bulking photos:

Mesomorph vs Ectomorph – totally different approach needed to get an aesthetic physique

What I find interesting about these photos is that after gaining 32 pounds, I was still smaller than Willem was after he lost 20 pounds.

Up until then, we had both lived in the same house, we had both eaten similar diets, and neither of us had been in the habit of exercising. It just goes to show how different people can be.

Well, actually, now that I’m thinking about it, I remember how Willem used to eat an entire box of powdered donuts every night. I was impressed with the sheer number of calories he could fit in his stomach. I wished I could do that.

In fact, I tried to copy that habit of his. In one of my many bulking attempts, I tried a dirty bulk that included many of those powdered donuts. I just couldn’t keep up with him, though.

I eventually learned how to eat more calories, but it didn’t come easily to me.

Ratio of Fat to Muscle While Gaining Weight

Anyway, if you think about it, it’s easy to see where all of the extra muscle comes from. Being in a calorie surplus is one of the best ways to stimulate muscle growth (study), and besides, those extra calories need to be stored somewhere.

If someone tends to overeat, they’ll gain a mix of fat and muscle. It depends on what kind of food they eat, but most people gain around 2/3 fat and 1/3 muscle (study). So if someone is 50 pounds overweight, that means they have roughly 17 extra pounds of muscle.

And it doesn’t stop there. The person has to carry all that weight around. If they go up a flight of stairs, they need to carry those extra 50 pounds with them. When they stand up out of a chair, again, they’re lifting those 50 pounds. Over time, relentlessly lifting those 50 pounds is going to stimulate a bunch of extra muscle growth their legs, glutes, and core.

Their legs naturally get quite a lot of work just through daily living. So simply because they’re heavier, they’re going to develop a stronger and more muscular lower body.

Furthermore, the more someone weighs, the more weight their abs need to stabilize as they go about their day. This means that overweight people will often have abs and spinal erectors that are naturally big and strong. This used to confuse me. I was lean, but because I had such small ab muscles, I still didn’t have an ab definition.

If you look at that picture of Willem and I up above, you’ll see that I’m quite a bit leaner than Willem is, and yet Willem’s abs are much larger than mine are, giving him much better ab definition.

That’s why most overweight people start off squatting and deadlifting quite a bit of weight, whereas oftentimes it can take a little longer to build up a big bench press.

Skinny guys, on the other hand, are often starting off behind the starting line. We can build muscle quite quickly while making our newbie gains, yes. However, it can also take longer for us to meet the classic strength benchmarks of benching 225lbs, squatting 315lbs, and deadlifting 405lbs.

Sumo Wrestlers Are More Muscular Than Bodybuilders

Did you know that the most muscular people on earth are sumo wrestlers? They have the highest amount of muscle mass ever recorded (study). They have more muscle than professional bodybuilders.

Pretty cool, right?


  1. […] That’s why overweight people start out so much stronger than us skinny guys. That’s why sumo wrestlers have more muscle mass than professional bodybuilders. That’s why some experts recommend aggressive bulking diets even for advanced […]

  2. […] we don’t just need to cut down to a low body-fat percentage, we also need to bulk up our abs. Most overweight people naturally have bigger muscles, including their ab muscles. For them, getting lean will yield great ab definition. However, for us […]

  3. Derko on November 9, 2020 at 3:46 am

    There is probably some genetics involved.

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