Aaaahhhh, the miracle of the placebo effect!
I'd give up Placebo, but it wouldn't do any good.
Of course there may be an extra placebo effect here. Not only does the person who had it done obviously think it may work, but it's so readily visible and odd that the stapled person inevitably has to explain it to his/her friends. Extra incentive to eat less and exercise more comes from the realization that you'll be the laughing stock of your social circle if you end up having to explain that it "didn't work" because it's clear you haven't lost any weight. In fact, it probably generates external reinforcement of this effect, by causing skeptical friends to periodically inquire "So is that staple in your ear working at all?", thus reminding the stapled person that "Oh sh!!, my friends think I'm really stupid and they're going to keep thinking that unless I lose a noticeable amount of weight".