As any parent will know, those early food costs rise steadily through the years. By the time your child is toddling about the kitchen cooing for juice, the average yearly food cost is $1,140. By school age, you’re paying $1,465 annually and a pre-teen is setting you back $1,835 per year.But that all pales in comparison to the $2,400 cost per year of feeding a ravenous teen.s any parent will know, those early food costs rise steadily through the years. By the time your child is toddling about the kitchen cooing for juice, the average yearly food cost is $1,140. By school age, you’re paying $1,465 annually and a pre-teen is setting you back $1,835 per year.