When I was new to this whole thigh ( I have never full timed it ) I would fill up my fridge. Then I realized when I was traveling across the country I probably drove past almost 100 supermarkets every day. I would not pack more that a few days worth of refrigerated food while moving around, and a couple weeks worth in dry goods and caned goods. If you plan on staying someplace for a long time then it is OK to stock up. I often travel alone and I have health problems. I like to keep enough food in the RV to have something to eat if I am too ill to drive. About 5 years ago I was in a truck camper and got ill, I parked at a truck stop some place in PA or VA and lived on canned goods till I fetlt well enough to drive. If you have any kind of health issues with no way of driving to a food market you may want to consider keeping enough food to survive till you are well enough to drive. a few years a got I was driving a Penske rental moving truck and got sick. I lived on potato chips sand cookies from the snack machine till I was well enough to drive.
You should base your decision on many things, room to store food, health issues and if you are ill can you have someone drive to a food mart to buy food if you run out. After you spend time on the road you will know what your requirements are.