Just to add to what C-W-S has already mentioned;
-airport food options are very poor for a 'normal' meal in BOS
-you could eat in the Hilton that is a 5 minute walk away and attached to the airport but that would have to be before you go through security obviously
-for anyone else reading this, you need to be flying first or CW to actually eat in the BA lounges, if you are Silver or Gold that doesn't count (you can still go in the lounge and drink or have the snacks but you can't sit or eat in the dining areas)
Have a good trip!