I'm not saying McDonalds doesnt expect something out of this arrangement, but you can't just assume its all bad until you know all the details, which you obviously dont. How do you know there cant be a mutually benefitical arrangement? Thats why you're a conspiracy theorist

Was the school supervisor really "show-boating" because he sent a memo to his schools saying no more MCdonalds in school, then in some other form of communication said he was keeping the gym program?

Good or bad, advertising is and is going to continue to be a big part of every persons daily life, including your children. If your kid is unable to learn what aspects of it are bad for him, and what are good, I'd think you'd either need to re-evaluate your own parenting practices, or perhaps consider putting your kid in a "special" school. Its called thinking for yourself and making your own decisions for what is best for you. We all make bad decisions now and again, but the idea is to learn from them.
That kind of thought is exactly why America is fat today. There is no personal accountability for your actions. Its not Mcdonalds, or Burger King's fault your fat, its yours alone.