^ You might want to recheck your math.
I must have been sleeping at the switch or something. Let's try this again.
300lb man, who likely only have 180lbs of other tissue and bone mass (that's actually quite a bit, it means this guy is pretty thick naturally). So he has 120lbs of adipose tissue on his frame. This seems to be about 40% bodyfat, which is quite high, it's almost half his weight in fat.
So, let's say that he wanted to get down to 25% bodyfat, he would have to lose 45lbs, to get down to 255lbs.
I would say the difference in look would be staggering, and this is totally within reach of most people, even if they have minor health problems.