Here is the NY Times, describing the latest weight-loss fad:
Like almost every dieter in America, Wendy Bassett has used all sorts of weight-loss products. Nothing worked, she said, until she tried Sensa: granules she scatters on almost everything she eats, and which are supposed to make dieters less hungry by enhancing the smell and taste of food.
The maker of Sensa claims that its effectiveness is largely related to smell: the heightened scent and flavor of food that has been sprinkled with Sensa stimulate the olfactory bulb — the organ that transmits smell from the nose to the brain — to signal the “satiety center” of the hypothalamus. Hormones that suppress appetite are then released.
Unfortunately, I think Sensa’s approach is exactly backwards. Delicious smells are what psychologists refer to as a “hot stimulus,” a sensory provocation that makes us want to eat. I described this process in my recent New Yorker article on Walter Mischel and the marshmallow task, a simple experiment in which four-year olds attempt to not eat the tempting treat right in front of them. The question, of course, is why only some children are able to resist, while others gobble down the marshmallows (or oreo cookies) in less than thirty seconds:
Mischel’s conclusion, based on hundreds of hours of observation, was that the crucial skill was the “strategic allocation of attention.” Instead of getting obsessed with the marshmallow–the “hot stimulus”–the patient children distracted themselves by covering their eyes, pretending to play hide-and-seek underneath the desk, or singing songs from “Sesame Street.” Their desire wasn’t defeated–it was merely forgotten. “If you’re thinking about the marshmallow and how delicious it is, then you’re going to eat it,” Mischel says. “The key is to avoid thinking about it in the first place.”
The problem with Sensa is that it makes it harder to not think about food – we can’t strategically allocate our attention because those delicious smells keep on reminding us how hungry we are. If anybody loses weight on Sensa, I’m betting that it’s placebo effect at work, and not some hypothalamic pathway.
This nasal product, though, seems much more promising.