I'm sitting here looking at a coke can. It's less than 3 inches in diameter. If anyone on this forum thinks a 5-6 foot snake with a girth of maybe 8 inches (widest point) is obese, I'd have to say you're smoking crack.
I'd also like to say that you absolutely cannot make the jump from humans and obesity to snakes and obesity. We're talking about natural metabolisms and growth rates. A human born at 7 pounds might be expected to weigh 40 pounds at age four. That's less than 6 times the birth weight and 3 times the height.
A burmese python is equipped to grow from a hatchling length of under 100 grams and 18" to 12 feet and 27 kilos(I'm using examples of wild caught males) in the first four years. That is an increase of 8 times the hatchling length (or more) and 270 times the increase in weight.
I used wild caught examples because this will be on the low end of potential growth. Obviously, females grow faster and bigger. Obviously animals maintained on a more generous diet will grow faster. These are not true of humans.
If you overfeed even an infant child, it will become obese...it's not going to grow 6 feet tall. If you overfeed a baby burmese python, it will grow faster, it doesn't store the fat like an adult animal will. Now, there are skeletal implications when utlizing a high growth feeding schedule, but that's another story.
K. Royer