Like everything, too much of a good thing is a bad thing. Now, if you have heard people talk about not eating after 7 pm bc it will make you gain weight, it's true. Your body is set to a natural internal clock. It knows what time a day it is whether your brain does or not. That's how you know when you are hungry, sleepy, etc. Eating after 7pm will make you gain weight because your body is settling in for the night and the metabolism slows, causing fat deposits to be stored. Those fat deposits are cellulite. Now on the other hand, sitting around doing nothing will also slow your metabolism. Everything in your body is linked. The faster your heart beats, the faster your metabolism will be TEMPORARILY, meaning that you burn calories and fat. So yes, to answer your question, sitting too long and sleeping after a meal will indeed cause cellulite.