Animals like deer store fat around organs and behind the eyeballs, which would have been consumed by humans historically.

“a big animal with fat that's a fair point yeah way more fat i mean most salmon is really lean um yeah that's that's the funny yeah when you get the farm raised crap it's pumped full of fat and it looks you know completely different ball game than a traditionally wild caught sake you can tell there's barely any fabric yeah and you'd have to get a big animal even wild deer doesn't have that much fat you have to like really if you've ever hunted anyone that has hunted knows there's fat around the kidneys on the deer there's fat behind the eyeballs all of this would have been eaten and the brain is full of fat the bone marrow we would have gotten all that fat is so precious in nature”