I'm not on the food program yet, but I'm providing food like I am so it won't be a challenging transition. Since DD has a nut allergy it's been easy for me to just enforce my food allergy rules and say "I provide whole milk; you may send in soy milk in the
original packaging. No other options." Other than removing child-specific allergens from the menu I don't adjust my meals or food policies for anybody because it's a life and death issue for families with food allergies, including my own family and two others currently enrolled.
Fairly sure one of my first families tried to sneak almond milk in one day in a glass bottle, claiming it was soy.
I respect people who have nontraditional diets for ethical reasons, and I accommodate people who have nontraditional diets for digestive reasons, but when there's an anaphylactic allergy in play those other two groups dang well better adjust their habits so they don't kill somebody.