STEVE INSKEEP, HOST:
Next up, the zero-calorie diet. This is a concept that comes out of some research that's been studied by NPR's Shankar Vedantam, who joins us once again. Hi, Shankar.
SHANKAR VEDANTAM, BYLINE: Hi, Steve.
INSKEEP: OK, what's the research?
VEDANTAM: Well, this is research about what it takes to be satisfied, what it takes to feel full when you've eaten something.
INSKEEP: OK.
VEDANTAM: We all know when you have dessert, for example, the first bite of dessert tastes better than the fifth bite of dessert. And that's because by the fifth bite, you've started to get a little full.
INSKEEP: Or the 15th in some peoples' cases.
VEDANTAM: Exactly. There's new work out that asks whether we actually need to eat something in order to feel satisfied. Is it possible that merely seeing a certain kind of food it can produce the same effect?
INSKEEP: And?
VEDANTAM: Jeffrey Larson, Joseph Redden and Ryan Elder find that you can to some extent feel satisfied by the mere sight of food. They find that when they show volunteers lots of pictures of salty foods, for example, people start to enjoy salty food less. And in fact, the more pictures people see of the salty food, the less they enjoy it afterwards, which suggests that there is a response to the amount of pictures you're taking in - the more pictures you see, the less you are hungry afterwards.
INSKEEP: Wait a minute - wouldn't the opposite happen here? If I'm looking at pictures of food, wouldn't that make you want to get food? Certainly Burger King advertisers think so.
VEDANTAM: Yeah, that's what I would've thought as well, Steve. Now, it is the case in this experiment that the volunteers were exposed to lots and lots of pictures. They saw hundreds of pictures of salty food. So it may be that if you really want to kill your appetite, seeing one or two pictures won't do it, but seeing 200 might.
INSKEEP: Flip through a Nigella Lawson book.
VEDANTAM: Exactly.
INSKEEP: Shankar, thanks very much.
VEDANTAM: Thanks, Steve.
INSKEEP: That's NPR's Shankar Vedantam. You can follow Shankar on Twitter @humanbrain. This program is always @morningedition and @nprinskeep. Also, you can find, by the way, Audie Cornish.
AUDIE CORNISH, HOST:
@npraudie.
INSKEEP: People are excited to have you here this morning, Audie. Although I'm already getting Twitter messages from people thinking it's, like, 5 pm, it's All Things Considered time. Anyway, good morning, this is NPR News. Transcript provided by NPR, Copyright NPR.
