... consume fewer calories loses weight. They even made a television show out of it. "Increase exercise, decrease calories" is literally the basic formula for "Biggest Loser," and people always, always lose on that show. (There are a host of other problems with how they do what they do, and what happens to contestants afterwards, but we're talking about the chemical equation of calories in vs calories out, of which the show dramatically validates.)

It's happened to me, it's happened to members of my family, people I know, people I've read about. It really is that simple.

Also, nutritional guidelines (like the Food Guide Pyramid) are not the same as caloric guidelines. Wanna know one reason why the FGP didn't work? Eating as many servings of grains as it recommends leaves one feeling less full, thus increasing people's tendency to overindulge. Couple that with massive increases in food availability, a society-wide transition towards sedentary lifestyles, and processed foods that have filler calories as a substitute for fat (demonized as part of the "nutritional guidelines" you mentioned), and it doesn't take the ridiculous pseudoscience in that link you mentioned to explain what's happening.

Show me an overweight person, and that person (nearly always, excepting a few--rare--medical conditions) eats too much or doesn't move enough.