Lets take a moment to reexamine his height and weight. He's suppose to be 7 feet 5 inches tall and weigh about 172 pounds. I'm 5'7 and 165 pounds right now. I'm a bit on the chubby side but not a fat guy by any means. Sagat is suppose to be nearly 2 feet taller while weighing only 7 pounds more even though he looks as muscular as the guy who plays The Mountain from Game of Thrones. And that dude is 6'9 390 pounds.
It does look like everybody has been lifting in SFV and has gotten heavier now though. Ryu was listed 150 nearly his entire life but he's 187 in SFV now. If Sagat is in SFV, he shouldn't be listed any lower than 300. That would at least put him in Yao Ming tier, and he's packing a fair bit more muscle than Yao.