system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do weightlifters looks “fat” rather than just pure muscle?
gpt
To build muscle, you need to lift weights and eat a calorie surplus. The extra calories allow you to grow -- both muscle and fat.

Body builders then cut -- they stop eating as much, but keep working out, to reduce the fat. 

But for weightlifters, the cutting is just a waste of time. It makes more sense to keep eating and keeping building muscle. (Mind you, they need to cut a bit, they can't get so fat that it gets in the way, but they don't need to be crazy low fat like body builders). 

All the same muscles are there, they just aren't as visible.