I think in a situation like this you have to have a snack even if it fills you up too much to have a proper dinner. If you know you have this vulnerability at that time of the month, you also have to be prepared. I would keep vanilla yogurt, milk or better - if you can get it - kefir in the fridge and frozen berries in the freezer, and make yourself a healthful smoothie any time a situation like this arises. You will be glad you did. I can give you a recipe.