Im just throwing a blanket statement about animals, obesity, and the breakdown of food in general, I dont know the science on how it affects snakes at all. Snakes may digest food differently than other animals but the basic biological systems and internal functioning of cells is essentially the same in MOST animals whether or not they have very different physiology or anatomy. Its just my belief that any animal that is obese is at risk of negative health effects. I feed my snakes every 7 days and they dont seem to be overweight at all, so I dont think feeding snakes every week will cause negative health effects but I'm not a experimental researcher either, so..... I think that someone would have to consistantly and intentionally powerfeed a ball python in order for it to become obese