How Smell Affects Weight Loss

Losing weight might be as easy a plugging your nose while nibbling on that heaping plate of bacon. CBS News reports that a new study revealed that mice who didn’t have a sense of smell actually lost weight compared to their furry counterparts who could smell the fattening foods they were eating. So your great sense of smell really could be sabotaging your diet plans.

According to the news outlet, mice that were able to smell gained twice the amount of weight as those that couldn’t. Additionally, there were a set of mice who had super-smelling abilities and they were compared to those unable to detect scents. Mice with extra powerful sniffers gained even more weight than those with a normal sense of smell.

Study author Céline Riera told CBS, "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.”

Riera thinks the new finding is promising for future weight loss treatments. "The cool thing about olfactory nerves is that they are totally unique. They're not in brain, they're in the nose. Maybe in future, we can non-invasively block them in humans. Maybe if you can remove olfaction in the patients for several months, it may help them lose weight," she said to the publication.

Andrew Dillin, senior study author and professor at the Howard Hughes Medical Institute in Maryland said that if this finding also is true in people, then researchers could find new alternatives to more extreme measures like bariatric surgery. "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," he told CBS.

This study also shows how complex weight loss really is. While most believe it’s just a matter of burning more than you eat, this study shows that’s not the full story.

"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."

According to Authority Nutrition, calories in vs. out is oversimplified because different foods affect the body differently as they’re processed and turned into the energy we use. A story in Harvard Magazine also asserts that not all calories are created equally.

Dr. David Ludwig, who teaches pediatrics at Harvard Medical School and nutrition at the university’s school of public health, says it’s not overeating that causes weight issues. Ludwig says that instead, the hormone insulin is a major cause.

“We know that excess insulin treatment for diabetes causes weight gain, and insulin deficiency causes weight loss,” he said to the magazine. “And of everything we eat, highly refined and rapidly digestible carbohydrates produce the most insulin.”

Although complex, most doctors agree that the best way to lose weight is to eat a balanced diet with plenty of vegetables, lean protein, fruits, and incorporate exercise.