Millions have been served to children across the nation in varying stages of life, and they are an integral part of the nutrition of growing children.
Children who may not receive a warm, home-cooked dinner can receive one at school.
Nutrition  standards have been upgraded to include more fruits and vegetables, and meals must include whole grains. Calorie standards must be adhered to.
There has been some complaining at some schools about the calorie count; 650 for grade schoolers, 750 for middle schoolers and 850 for high school children.
Multiply each times three, and that is plenty of food for the day. Children are supposed to be hungry at supper time. If they’ve had a full day of hard mental work and school, combined with outdoor play and athletics, they are ready for supper.
If their child requires more food, the parents should be the parent and provide enough breakfast and supper for their own children. The school meals are extremely inexpensive for the amount of food the children receive.
When provided with healthy food, children will eat as much as they need once they become accustomed to it. However, many children are used to eating high fat and high sugar. The taste buds become accustomed to this type of food. Those taste buds can be retrained.
This is the way humans are supposed to eat. There are not a lot of emaciated children. Instead, there are large numbers of obese children. Walk into any classroom today, and  a good third of the class is obese.
Good nutrition is part of the fight against diet related diseases such as diabetes, high cholesterol and high blood pressure. If a child develops this at age 13 due to obesity, the prospect of long term health is extremely low.