Fat people seem to have a finer sense of smell than others but only when it comes to food. It is thought that an extra sharp sense of smell makes it harder for them to say "no," which is why they pile on the pounds, says a new research.

Although overeating and little to no exercise are mostly to blame for the obesity epidemic, many experts believe that other factors are also at play. These could include the sense of smell.

A study looking at weight gain and sense of smell found that when it comes to everyday scents, those who are overweight have less sensitive noses than their leaner friends.

Yale University has conducted a study suggesting that our ability to smell what we eat may affect how much we consume. They say their findings may go towards explaining why some people struggle to stay slim.

They also found that overweight people with a high body-mass index (BMI) are better at detecting to food odors than people with a low BMI and high-BMI types are still open to temptation by pleasant aromas. As smell is key to our sense of taste, this could actually make it difficult for them to stop eating, even when they are full.

"These findings highlight the need for a more individualistic approach in identifying factors that may increase risk for weight gain," Dr. Barkha Patel, lead author of the study said.

Dr. Dana Small, a Professor of Psychiatry at the Yale School of Medicine in the US, called for "future work to assess imagery ability directly rather than relying upon self-report measures."

Although it’s impossible to draw conclusions from a small study, but researchers say it may be possible that fat people have trouble putting their forks down when the smell of a meal lingers, and that this leads to overeating and weight gain.