Yoni Freedhoff is the most important person I can bring to your attention. He is an Obesity Doctor in Ottawa who is one of the few voices out there who attacks the sources of North American obesity rather than the kids. His blog is called Weighty Matters and he'll never run out of things to post. He photographs the food choices offered in hospital cafeterias, publishes video clips of junk food advertising embedded within tv shows, food advertised as healthy choices which aren't, etc.
I wish mankind were evolving into a kinder species but it only changes which group it discriminates against. Young children have only a limited arsonal of ways to self-medicate, to punish themselves, to protect themselves, to comfort themselves. They don't have the option of coming home from a rugged day and choosing from a variety of substances to make themselves feel better or quitting their job or divorcing their parents or firing any professional that just plain doesn't like them. No group faces more play ground discrimination, no group gets a clearer message that people would rather be dead than like them. It's even ok now for professionals to advise parents to not allow their children to be friends with a fat kid and maybe it's even a health risk to be a friend of a friend of a fat kid.
Rather than hurting a fat kid which is really easy to do, think carefully about how much money your school receives from companies that produce junk food and beverages, how many fundraisers involve selling high fat food, and assess what exactly are the food options available in your cafeteria with special emphasis on fat, sugar and salt content. If it comes out of can, the salt content is probably amazingly high and that includes soup. And forget trusting the healthy labels - the organizations that put healthy labels on food are just as dependent on the food industry for financial support as are our schools and the hospitals. Healthy food choices and organized, high quality activities cost money and are rarely available in the neighbourhoods that need them most.