I don’t have much fat on me to be honest, ( and I eat like a horse just lucky I guess) I use stomach and legs without any problem , I do rotate regularly , I’m on Bolus, Basel regime, I don’t put them into particular areas , just whatever grabs me at the time, as long as you can use particular areas I think the most important thing is to rotate sites if you’re unfortunate to only be a be able to use one site make sure u don’t use same spot continuously as that’s when poor absorption can be a larger problem