Dave is right. There's science behind this, studies to debunk the stuff, but I can't point you to them just now. For decades, the hype was, "nobody knows how, but it does this..." but it doesn't. That's why nobody knew how. Carapils/CaraFoam at 1-2% can definitely give a pleasant and clearly distingushable nutty taste in a beer light and clean and delicate enough to detect it in. Use it for that if you like (even though it's commonly referred to as flavorless!) But it not only doesn't help with foam and body -- Dave sells it short there. In fact, every beer I've ever used it in had inferior body and foam compared to the same beer made without it. (I have my own pet theories about some mechanisms behind this, in addition to others I've read.) The conventional proposition seems to have been something to do with unfermented "malto-dextrines" making some positive contribution. But already in the 19th century, scientific brewing texts deride this as a quaint myth circulated a couple of generations earlier, asserting rightly that such unfermented sugars make for a thinner palate and less stable foam. So why do the manufacturers still advertise it in the familiar way? People keep paying them for the stuff.