The food environment, such as pictures or smells, can influence the behavior of people even when they are not paying attention. In fact, are the smells perceived in a careless way have influence on food choices ? The answer is yes, according to INRAE researchers, who had for example shown in the past that an odor of fatty or sweet food makes you want to eat more. choose foods that match that smell like cakes. But do these smells have an influence on our control and our inhibition vis-à-vis? caloric foods ? This is what scientists sought to find out in a study published in Plos One.
For this, the scientists had a computerized cognitive task performed on individuals of normal weight, overweight or obese. These participants had to detect target images and ignore “distraction” images according to the instructions heard, without being informed that they were exposed to odors. Indeed, these people wore a headset with a microphone to hear the instructions, and it is the foam covering the microphone that was subtly impregnated with an odor, either pear (low calorie food) or pound cake (food caloric) or non-odorized. On the screen, pictures of food and objects appeared successively.
A link between unconscious odors and too much information
The volunteers had to either detect the images of food and ignore the images of objects or vice versa. These two instructions alternated several times, which temporarily increased the amount of information to be retained, and therefore the difficulty of the task, this one also being called “Cognitive load”. The reaction time and the control capacities of the participants were measured in a situation of cognitive load (more or less information to remember) and according to theexposure to different smells. The results indicate that odors, even not carefully perceived, had an impact on the responsiveness of those who presented overweight or suffering from obesity.
Indeed, the latter were slower when they were respectively exposed to a smell of pear and pound cake only when they had not been exposed to any odor. In addition, cognitive load has an influence since participants made more mistakes and had more difficulty self-control in the face of food images when they had a significant amount of information to keep in mind. “Thus, although the attention of obese individuals is automatically more attracted to high-calorie food images when they are exposed to a smell of fatty-sweet food, however, this does not seem to affect their ability to control, ”explain the scientists.
Their results therefore show that it is not so much the odors, nor the weight status of the subject that influence these capacities, but rather the quantity of information, namely the cognitive load. For researchers, this work is important because it provides a better understanding of how cognitive processing of environmental information can influence eating behavior in people of different weight status. By taking a closer look at the link between overweight and an “obesogenic” environment, they will also make it possible to “identify what sources of vulnerability can lead them to have problems. deleterious behavior », They conclude.