Today at Feministe piny (sorry, I originally credited zuzu; thanks Sara for setting me straight) has some interesting answers to similar questions. Among the answers was something I certainly hadn't thought of in this context:
Model comfortable eating. Cook for them. Invite them over for dinner. Take them out to dinner. Make them pancakes or waffles for breakfast. Stop for snacks. Carry snacks. Go to farmer’s markets and festivals. Start potlucks or movie marathons or bakeoffs. Engage in activities which build appetite, like hiking or long walks on the beach. Make eating routine. Make cooking artful. Connect it to good company and conversation. Create safe space for food.