Tom Toles hit it on the head yesterday, and that dovetails nicely with the article Unhappy Meals by Michael Pollan in the New York Times Magazine awhile back (thanks Elizabeth!), which starts with a handy rule of thumb:
…if you’re concerned about your health, you should probably avoid food products that make health claims. Why? Because a health claim on a food product is a good indication that it’s not really food, and food is what you want to eat.