Just a general question regarding growth and muscle building

So how do gorillas grow 700lbs in captivity and tigers grow 400lbs while we have to stimulate the muscle to break down for growth?

Animals get larger than humans and the larger you get the more weight your moving around and the more muscle you build. A cow can walk around a field eating grass, stimulating the muscle all day and get muscular because it's carrying around 1,500 lbs.

Genetics? We grow as much as our ancestors needed to grow in order to survive.

I see the point of your question, at it's most basic, and despite our similar DNA with gorillas, we're just different creatures. It's a bit like asking why mice require so little food to maintain their size and strength relative to humans. Gorillas, tigers, humans, mice, etc, all have different skeletal structures, respiratory capacity, bone density, etc. Gorillas have physiology that supports larger bodies than humans.

I tried to find home density numbers, but found this instead: https://animalmentor.com/wild-life/p...-are-gorillas/