There’s nothing quite like catching a whiff of some really good food. Whether you’re entering a restaurant, passing by your next door neighbor’s barbecue shindig, or visiting your mom at Thanksgiving, you probably know what it’s like to instantly crave whatever delicious aroma that filters through your nostrils.
But could your sense of smell be powerful enough to influence your weight? Scientists seem to think it’s a real possibility.
In a recent study from the University of California, Berkley, scientists examined how smell influenced the eating habits and body weight measurements of lab mice. When the scientists gave obese mice a substance that would cause them to temporarily lose their sense of smell, the mice ended up losing weight.
That’s not exactly surprising since we all know how our sense of smell is tied to taste. It seems obvious that the mice simply craved less food due to their inability to smell it, but that wasn’t the case at all.
The smell-deprived mice weren’t eating less because they couldn’t smell their food. In fact, the smell-deprived mice were eating just as much of their high-fat diet as normal mice that hadn’t had their sense of smell altered.
Strangely enough, while the smell-deprived mice lost weight, their smell-enabled counterparts ended up ballooning to twice their size. In another experiment where scientists manipulated the mice’s sense of smell so that it was sharper, the mice ended up gaining even more weight on a high-fat diet than normal mice.
Scientists know that the part of the brain that regulates metabolism is connected to the olfactory (smell) system, and the results of the study hint at the fact that there may be a lot more going on than originally thought. Smell might seriously influence how the body uses calories, whereby the inability to smell food triggers the body to burn those calories off rather than store them as fat.
“This paper is one of the first studies that really shows if we manipulate olfactory inputs we can actually alter how the brain perceives energy balance, and how the brain regulates energy balance,” assistant professor Céline Riera Cedars-Sinai Medical Center said in a statement.
Sense of smell in both mice and humans is more sensitive when in a state of hunger compared to a fed state, so it’s possible that the brain is tricked into thinking that the body has already been fed when no smell is detected. If no food is obtained, calories may be stored as fat just in case the body has to go longer without food. But if the body has been fed already, calories may be burned off.
“Sensory systems play a role in metabolism,” said Andrew Dillin, molecular biologist at the University of California. “Weight gain isn’t purely a measure of the calories taken in; it’s also related to how those calories are perceived.”
The scientists hope that if that the results they got in mice proves to be similar in humans, they may be able to work on developing a drug that blocks the metabolic connection without altering people’s sense of smell.