If you have food allergies or other dietary requirements, talk to the hotel. They will do anything possible for special diets, including substituting any ingredient they have in the kitchen for what the dish comes with. They have gluten-free rolls, breads, and pastries and will substitute vegetables, fruits, or whatever for sides and ingredients that are not on my low-carb, low-fat, low-salt, non-dairy, non-fermented diet. If you need something special, let them know in advance and they will have it on hand. The room service menu, which is more extensive, id available at Sauciety in addition to your room. Call the Sauciety Restaurant Manager at 617-532-4600 if you need to discuss any special food needs.
Don’t forget that MJ O’Connors and the City Bar are not managed by the Westin, so they may not have the kind of menu flexibility the Westin may be capable of.