I used to weight 420 lbs. I had type 2 diabetes, high blood pressure, severe sleep apnea (which could have literally killed me dead any night I forgot the CPAP), asthma, high cholesterol, IBS, and was diagnosed with type 2 bipolar disorder. I now weigh 194, have "the best cholesterol numbers [my doctor] has seen in a long time", energy to exercise, no breathing problems, I only poop when I want to now, and most of all I'm happy and stable without medication.
How did I do it, you ask? I realized that the USDA's purpose is to promote American grain-based agriculture (everything but corn, soybeans, and to a lesser degree wheat are considered "specialty crops") and not the health of Americans, and I quit following their stupid, lame, ineffective food pyramid. I save almost $10,000 in medications alone -- forget about all the other medical costs -- and I LOVE my tasty home-made bacon. That nasty corn, and wheat, and high-fructose-corn-syrup, and soybeans? Keep 'em the hell away from ME! I'd rather SMOKE than eat a school lunch -- it's better for me.
Want to lose weight? Grass-fed meats, vegetables (corn is not a vegetable -- except in school lunches!), fruit in moderation as a "treat". No added sugars of any kind. No wheat, corn, or god-help-us-soybeans-that-you-can't-even-eat-without-fermenting-them-because-they're-literally-inevitable-best-suited-for-feeding-pigs, ever.
Since the government started setting "preventative" nutritional guidelines, based on the then-unproven "low fat" theory from Dr. Ancel Keys, in 1977, have Americans gotten thinner or fatter? When the USDA publicly acknowledges that there is no "one true diet" for all humans, regardless of their ethnic background (and how recently that area developed agriculture) I MIGHT listen to them again. Until then, I think it would be insane to listen to them -- insanity being doing the same thing again and again and somehow expecting a different result.
It annoys me that the schools keep trying to tell my children that a low-fat diet is good for them. I can't imagine what I'd do if they started trying to force their hog-feed down my children's throats, but it would not be pretty.