It's no secret that how you experience your food is linked to how it interacts with your senses. I mean, who hasn't been tempted to indulge in some baked goods after walking by a bakery? But next time you want to loiter a little longer near some cookies, thinking there's no harm in smelling, consider this: A new study from researchers at the University of California Berkeley has linked food aroma to your weight. Specifically, sniffing foods may trigger your body to hoard calories instead of burning them.
The study, published in the journal Cell Metabolism, made a connection between olfactory neurons (aka the neurons that help your brain process smell) and weight gain through three experiments.
In one experiment, the researchers found mice with a normal sense of smell gain more weight on a high-fat diet than mice with impaired olfaction. That's the case when you take variables like quantity of intake and activity into account.
"I was shocked — the effect was so robust," Andrew Dillin, the study's senior author and a professor of molecular and cell biology and Howard Hughes Medical Institute Investigator, tells the LA Times. "I was convinced they were just eating less. When it became clear they weren't, I thought, 'Wow, this is incredibly interesting.'"
In a separate experiment, the team took the obese mice and temporarily inhibited their sense of smell to find they lost weight. Specifically, a third of their body weight. A third test had the researcher create mice with heightened sense of smell — called "super-smellers" — by blocking an olfactory receptor in the brain. These subjects were at greater risk of gaining weight.
Findings from a rat study don't necessarily translate to humans, but it does shed insight into how smells impact metabolism. Since the researchers found food odors to determine how our body deals with calories, the study's findings suggest that if you can't smell your food, your body may burn more calories rather than store it. This, in turn, can potentially provide a solution for those struggling to lose weight.
"Sensory systems play a role in metabolism. Weight gain isn't purely a measure of the calories taken in; it's also related to how those calories are perceived," Dillin says in a statement. "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."
It can also help people struggling with eating disorders.
"People with eating disorders sometimes have a hard time controlling how much food they are eating. and they have a lot of cravings," Céline Riera, co-author of the paper, says in a statement. "We think olfactory neurons are very important for controlling pleasure of food and if we have a way to modulate this pathway, we might be able to block cravings in these people and help them with managing their food intake."
The findings are noteworthy but far from conclusive in humans, which means if you're a chronic sniffer, you can continue enjoying the smell of food. Just don't be too alarmed if researchers are able to prove the same effect in human trials.