In one of my families that I was playing earlier today, not one of the 5 members would prepare a meal. I would drop them at the table and they said "NO!"

Then I checked the refrigerator and they only had about 20 of food. So I bought them groceries and, once they had been put away, I had no problem getting one of them to prepare a meal.

Also, once I have meal on the table and everyone is eating, then as they leave the table I check their food bar. If it is not full, I put them back for a second meal. That way they don't have to fix meals as often.