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Can Smells Make You Fat?

Study finds link between weight gain and sense of smell

Food smell

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Study finds sensory systems play a role in metabolism.

If you’ve ever said, all I have to do is smell food and I gain weight — a new study says you may be right. The delicious aroma of baked goods or the alluring smells of pizza can not only make you feel hungry, but enjoying the scent of high-calorie, high-carb foods may also expand your waistline.

A new study out of the University of California, Berkeley, and published in Cell Metabolism found that one's sense of smell is linked to weight gain. But how can that be? The study says it is possibly related to the way your body stores or burns fat.

Senior study author Andrew Dillin, professor of molecular and cell biology at UC, Berkeley, says, “Sensory systems play a role in metabolism.”

Indeed, the study links metabolism with sense of smell and appetite. The food you can’t smell gets burned off instead of stored, while food that stimulates your senses will likely get stored as fat and become added weight. “Weight gain isn’t purely a measure of the calories taken in; it’s also related to how those calories are perceived,” adds Dillin.

Researchers used mice separated into three groups — a group that had a boosted sense of smell, a group that had their sense of smell temporarily disabled, and a control group. Each of them ate the same high calorie food — a Burger King diet.

The results showed the mice with a super sense of smell gained the most weight — nearly doubling in size. The mice with a disabled sense of smell gained 10 percent of their body weight and the control group gained less than the super-smellers and more than those that couldn’t smell.

Even though it is surprising that sense of smell appears to be so closely related to how the body metabolizes food, the results of this study could be very beneficial for future weight control research.

“If we can validate this in humans, perhaps we can actually make a drug that doesn’t interfere with smell but still blocks that metabolic circuitry. That would be amazing,” says Dillin. “For that small group of people, you could wipe out their smell for maybe six months and then let the olfactory neurons grow back after they’ve got their metabolic program rewired.”