Two researchers from the University of South Florida have shown that smelling food for more than two minutes makes it less desirable for us. This is because the sense of smell is able to gratify the reward circuit in the brain through a mechanism called "cross-modal sensory compensation". As a result, environmental scent could be an effective weapon during weight loss therapies.

When we smell the fragrance of a delicious food for a short time, our desire to eat it grows dizzily, but if the smell persists in the environment for at least two minutes our brain feels gratified and rewarded, making the food less palatable. In other words, the prolonged scent of food can ‘satiate' the brain and therefore direct us to consume different foods, perhaps foods with less calories and more healthy. Used strategically in a diet, perfume could be therefore a very effective weapon to make us lose weight with less sacrifice.

A matter of time. Two researchers from the College of Business at the University of South Florida, marketing professor Dipayan Biswas and Professor Courtney Szocs discovered that the lingering scent of food is able to gratify the reward circuit of the brain. Through various experiments, the two scholars have shown that there is a close correlation between duration of exposure to the scent of food and the desire to consume it.

The study. Biswas and Szocs gave the research participants a small nebulizer that separately emitted the smell of contrasting foods, the first with more calories and the second ones healthier, such as cookies with strawberries and pizza with apples. The participants exposed to the cookie smell for less than 30 seconds were decidedly more likely to want to eat one, but when the smell persisted for more than two minutes the participants tended to crave strawberries. The same result was obtained with the smell of pizza and apples.

Why the smell satisfies us. According to the two authors of the research, the scent of food seems to activate the so-called cross-modal sensory compensation in the brain, meaning a sense (in this case the sense of smell) is able to gratify the reward circuit and consequently the actual desire for food decreases. For this reason "environmental perfume can be a powerful tool to resist the desire of the most attractive foods", said Professor Biswas. The results of the research were published in the specialized scientific Journal of Marketing Research.