This is Scientific Americans 60 Second Science.

I'm Karen Hopkins.

I don't believe in all my years I've ever seen a fruit fly I would consider obese. But thanks to the wonders of modern science, that's

all about to change, because a team of researchers from Cold Spring Harbor Laboratory has produced

the first flies that are genetically engineered to overeat.

If you're wondering why, it's not as silly as it might sound.

A big part of weight control has to do with making healthy dietary choices

and knowing when to step away from the snack

cabinet. But what controls those behaviors? Well, we humans have a hormone called Lepton that tells us that

we're full. After eating, Leptons release from our fat cells, and it travels to our

brains to signal that we've had enough. Indeed, people who don't produce lepton, or who lack

the molecular machinery to detect it, really pack on the pounds.

In the new study, researchers discovered a hormone that acts the same way in flies.

And when they deleted the gene that encodes it, the hormoneally deficient insects just kept eating.

And when presented with the fly equivalent of a high fat or high sugar diet,

they gained three times more weight than did their hormoneally competent peers.

The findings appear in the journal

Cell metabolism. Interestingly, giving human lepton to these tubby bugs

eliminates their tendency to binge. Let's suggest by studying these flies

scientists might learn something that's relevant to us.

In the meantime, researchers from the UK and Australia have also been plying flies with sweet treats.

They found that consuming large amounts of sugar may lead

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