I will be 6 years out in August. Yes, it is normal to be able to eat more (otherwise you would be stuck trying to live on just a few ounces of food at a time with no fat stores to rely on!), but I have not noticed a change since about 2 years out. The diet we need to follow is the same as it was while we were losing (just in somewhat larger portions): limited portions (it is very easy to let portion sizes creep up as time goes by, and just because you physically can eat a certain amount doesn't mean that you need to, or should, eat that much... you still need to do some mental portion control), protein heavy, limited carbs (as few "white" carbs as possible), no drinking with, or right after meals.
I personally am not very active because of bad knees (just had one replaced), but am maintaining my weight by being more diligent about making good food choices. Exercise makes it MUCH easier to maintain your weight, but it CAN be done without it. There are several of us here that do.
Lora