I don't think the question should be posed as "Are schools obligated to "control" what our kids eat?" but rather "Do schools have a responsibility to "model" healthy eating behaviors and choices for our kids?" As a secondary level special education instructor, I have worked with many students labeled as "behaviorally impaired" "ADD" and ADHD" These last two labels have become particularly prevalent during the last decade, and there has been a good deal of speculation about whether high fructose corn syrup (a key ingredient in all sodas), excessive amounts of salt, sugar, grease and so forth have been factors in the boom of behavior disorders and learning disabilities.

Leaving that speculation aside, there can be no argument that we have also witnessed a boom in obesity and morbid obesity in our K-12 student population during the same ten year period. School lunch programs that promote the consumption of sodas, fried foods, salty chips, and sugar-laden baked goods add to the health problems and expenses that society at large will have to deal with long after these students have left the cafeteria.

We all expect our schools to help our students develop good reading, math and writing skills. It is not too much to expect our schools to also provide guidance and practice opportunities in the benefits of good nutrition and health management.

While kids are at school, the school is in charge of the kids well being--parents aren't there. Therefore it is appropriate to offer guidance--reminders of kids to eat their lunch including fruit and vegetables whether they are provided by the school or brought from home.
What I have seen happen at a private school in an upscale community on the Peninsula--In the morning getting off to school on time means kids eat minimal breakfast, then kids are in such a hurry to go play that they eat minimal lunch to get to play time. Then to be poplular with kids in their after school activities, teachers sometimes provide ice cream sundaes or other sweets at 5:00 PM which would be good if offered appropriately right after school, but at 5 PM, the kids then come home and aren't hungry for the only full balanced meal they might have had all day.

Schools should NOT be a source of junk food and sodas for kids. Parents are not there to monitor their children's intake of food and the fact that is there at school tells kids that the school is saying it is healthy--when those educated should know that it is not healthy at all. If cafeteria meals are mandatory, then it should be affordable to all, healthy and balanced and include a variety of fruit and vegetables so children can eat what is healthy AND what they like--carrot sticks, raw snow peas, apple quarters, grapes, water melon or muskmelon are among the favorites of many kids I know. If it is not affordable, then students should be allowed to bring food from home and hopefully parents can afford to offer healthy food that they prepare themselves.
I think schools have the opportunity to teach good nutrition and for some children it would be the best education they could get from the school and last them a lifetime.

Let's establish our premises:
1)We are talking about publicly funded schools.
2)We are talking about food the school makes available; either through providing it or allowing it to be sold on campus.
3)We are not talking about food the parents send or the student brings unless there is some financial transaction with other students.

That said, the public have a vested interest in
(a) teaching the students how to thrive in the modern world and
(b) preventing future costs to our society.
Future costs include medical costs, homelessness, economic meltdowns, etc.
The teaching includes (besides basic subjects) economics, health, critical thinking and decision making skills, and so forth. Not every student is college bound. Some go into trades, some the family business, and some other paths. They all need the survival (thrive) skills.
These vested interests mean the schools have the right and the duty to limit foods under their control to healthy foods.

Should they force the menu? Not unless the public funding (taxpayers) is willing to confront all the religious issues connected with diet. Otherwise they violate the separation between church and state. That is where the parents must supplement if they wish to impose additional restrictions.

Referring to premise #1, are we just talking about "public schools" or all schools that receive public funds or tax forgiveness through vouchers and tax exemptions? I hold that all such schools are included; but that may be a topic for a separate discussion.

I wanted to share this, a New Yorker article on just this, actually written about a berkeley school.
(the sad thing was how irritated the kids where about the healthier food, and how much got dumped into the trash)

www.columbia.org/pdf_files/chezpanisse5.pdf

I wanted to comment on the august program on low income and nutrition.
being low income, I was really interested, and wanted to hear about nutritious low cost food (cabbage, beans and legumes, eggs, etc) and other suggestions to cut costs.

the "nutritionist's" suggestions - add some chicken and vegtables to your ramen noodles, and buy food that is on sale.......
wow.
i didn't let my boyfriend change the dial for that?

1. if you can afford chicken and vegtables in the first place, why eat the ramen noodles?
2. one packet of ramen noodles says it contains three servings. It has over %54 percent of the RDA of saturated fat - the second ingredient of the noodles is palm oil, the second ingredient of the soup is sugar.
I think you would do a better service to your listeners to have a real dialogue about feeding themselves and their children in a healthy economical way

Since a majority of kids eat at least one big meal at school, it is imperative that schools provide healthy meal options for them. This includes offering more vegetables and fruits on the menu and offering healthy snack and beverage choices on their vending machines. This will encourage children learning about healthy nutrition choices which may also help influence what children eat at home. This will go a long way in combating the pediatric obesity epidemic.
As far as schools banning certain items from lunches that kids bringing from home goes, I have concerns that it may trample on civil liberties.

The road to hell is paved with good intentions. And greed.

The good intentions are found in the USDA $8 billion school lunch program that uses commodities for cheap, healthy food for kids. The greed is obvious when big food corporations manipulate the USDA into allowing corn syrup, trans fats, too much salt, pesticide-laden cottonseed oil, potatoes as veggies, and iceburg lettuce as greens.

Chef Ann Cooper in Berkeley Unified shows what is possible with the same limitations that all school districts face, where more is spent on the disposable tray and utensils and labor than on the food.

Dr. Antonia Demas has set the pace in research showing that kids will choose healthy foods if they have a little bit of classroom hands-on curriculum about them first. Their buy-in is incredible---they encourage others, take recipes home, skip the junk, and come to prefer the healthy foods.

As an elementary teacher, I have tried to educate students, parents, teachers, and administrators for the past 12 years, with zero results except with my own students. Maybe you'd like to see the articles I've put in one place, goodschoolfood.org.

The most recent addition to that site regards how vitamin D deficiency contributes to the Achievement Gap. This info alone would save California billions but it's an orphan idea no one will even consider.

If everyone killed their own food, the world would be a better place. I have a recipe for "African Stew" it calls for:
2 chopped carrots
1 cup of salt
1 cup brown sugar make sure its brown
2 chopped or diced africans

It is one thing for the school to choose what they serve or sell at the school. It is another thing for the school to have control of what I send in my child's lunchbox. I have a serious issue with this. As a treat, I brought my son apple slices, chocolate milk, and chicken nuggets from McDonalds for lunch. The school office told me he was not allowed to have it because it was fast-food and that was not allowed.
I would also like to know when the school system was given the authority to decide what my child eats. As a parent, it is my responsibility, to teach my children to eat a balanced diet. Under no circumstances, does the school system have the authority to decide what food I can feed my son.

It should be the parents responsibility, however look at the parents. Over weight, sugar diabetic, heart attack prone... who's giving them guidance? Junk food ads on t.v. that's who. The kids will crave the diet they are raised on.

Should schools allow sodas and junk food on campus. No, absolutely not. We are all in this together and who's going to take care of these poisoned bodies as adults? The healthy ones, that's who. It doesn't take a rocket science to figure out our interdependency. Why are your health insurance premiums so high? The weak links who go to the emergency room 8 times a year. The ones who believed that the Doctor would take care of them and went on using their mouth like a garbage can. They've outlawed junk food ads during kid tv. time in Finland and Norway. Smart people, they figured out who's paying in the end.

I think the more people or organisations that make it their responsibility to encourage children to eat better, the healthier they will be. But as a number of other people have said, it's ultimately the parents responsibility to drill it into the children and make sure it happens Control Systems Engineering