Only do what is profitable. Do it only if you have a market to sell food and turn a profit. If it can realistically lead to growth, then go for it.
We have a limited menu, but it is flexible. We have a core of menu items, lots of snacks, but also make specials. Here I cannot justify the added expense and effort involved in serving a full menu. We make better profit on pool, drinks and snacks which we sell a lot of. Out room is run by one employee and going bigger on food would not necessarily increase profits when you add another employee, equipment and food costs.
It really depends on your local market and the potential there is to grow.