What customer IDs have those order IDs?
select T3.customer_id from Products as T1 join Order_Items as T2 join Orders as T3 where T1.product_id  =  T2.product_id and T1.product_name  =  'food' and T3.order_id  =  T2.order_id
customer IDs that have those order IDs refers to selecting customer_id from Orders table; joining is required between Products, Order_Items, and Orders tables based on product_id and order_id; filtering condition includes product_name being 'food';