La [check-list] du Monde.fr de ce jour s’interroge : « Déjeuner à l'extérieur a-t-il un impact négatif sur la performance au travail ? »

C'est ce que suggère une nouvelle étude, dont la revue américaine PLOS One se fait l'écho. D'après des chercheurs de l'université Humboldt de Berlin, manger au restaurant avec un(e) ami(e) réduirait les capacités cognitives de l'individu et sa faculté à identifier des erreurs.

Les auteurs de l’étude présentent ainsi leur étude :

« Les repas sont d'une importance énorme pour les êtres humains non seulement pour assurer la nutrition et de l'énergie, mais aussi comme une institution culturelle et sociale. Par ailleurs, les repas sont une source importante de plaisir pour presque tous les humains. La recherche scientifique sur les repas est largement tirée par des préoccupations concernant l'impact de l'alimentation sur la santé physique et le bien-être mental. À cet égard - et d'un point de vue psychologique - il est évident que son régime alimentaire peut influer sur la cognition ainsi que sur les états émotionnels. Cependant, l'analyse de l'expérience personnelle montre que les repas semblent avoir des effets plus profonds. Un bon repas, en particulier lorsqu'ils sont pris en agréable compagnie, peut vous mettre de bonne humeur, elle peut favoriser de nouvelles idées, atténuer les tensions sociales, et promouvoir un accord mutuel dans les affaires, la politique et les familles. En d'autres termes, un agréable repas semble susciter ou modifier les processus émotionnels, cognitifs et sociaux. Fait intéressant, ces effets contextuels de la consommation alimentaire sur les processus psychologiques semblent être largement inexplorés sur le plan scientifique. C'était le but de la présente étude afin de réduire cet écart en enquêtant sur ​​les conséquences cognitives et émotionnelles d'un agréable repas pris au restaurant en dehors de l'entreprise par rapport à un repas solitaire, tout en contrôlant la quantité et la qualité de la consommation alimentaire. »

Ceci dit les conditions de repas aussi bien au restaurant qu’au bureau sont enserrées dans des normes qui transforment les convives plus en rats de labo qu’en joyeux collègues allant au resto ou s’offrant un repas en solitaire.

“Participants were advised to have enough sleep in the nights preceding the test sessions, not to consume unusual amounts of alcohol in the evenings before the test and to have breakfast in the morning of the testing days in accordance with their usual habits.”

On the day of the meal and post-meal session, participants were to refrain from eating and consumption of alcoholic beverages for four hours prior to the start of the experiment.

Each participant in the Experimental Group (EG) was asked to invite a companion of her liking for lunch. At noon she went with her companion to a medium-size Italian restaurant run by an Italian family who agreed with the arrangement of a restricted menu for our participants. In this restaurant, soft background music plays and guests are served by a waiter. The participants in the study were being served during lunchtime while other customers were present in the restaurant as well. Apart from the restriction of the menu and the “doggy bag” treatment of the left-overs (see below), the participants in our study were treated like the other customers. The restricted menu for the present study consisted of a selection of vegetarian meals taken from the standard menu and offered 7 pizzas, 12 pasta dishes, and 3 different non-alcoholic beverages, not including cola or coffee because of the coffein contents. Each participant and her companion were free to choose any of the aforementioned dishes and drinks. They were allowed 60 minutes for dining and were encouraged to eat at leisure. If the participant did not finish any part of the meal, it was placed in a doggy bag to be taken to the lab where it was weighed by the experimenter. Immediately after completing the meal, the participant walked to the lab (15 to 20 min), where the post-meal session of the study was conducted without further delay. All participants completed at least half of their meal.

Each participant of the Control Group (CG) received the same meal as her matched EG partner; that is, for the CG there was no choice of food. The meal was to be picked up by the CG participant from the take-away counter of the same restaurant were the EG had lunch. The participant had to bring the meal to the lab, where she was met by the experimenter. She was then shown to a small office room, in which she consumed the take-away food. If the matched experimental participant had not finished her meal, the size of the meal of the control participant was reduced – monitored with the help of an electronic scale – in order to equate the amount of food consumed by the matched participant pairs. The CG participants had 20 min to consume their meals, which is a very common duration of meals [5]. Unless the participant indicated finishing their meal would be uncomfortable, participants were asked to eat all of the food served to them. If a CG participant was unable to finish at least 60% of the meal, she was excluded from the study and replaced by a different matched person, to ensure that participants from each CG EG pair ate approximately the same amount of food. The room in which the meal was eaten was a standard office (ca. 12 m2) with plain office furniture and without decoration. During the meal no other person was present. No music or other media were allowed.”

How about Lunch? Consequences of the Meal Context on Cognition and Emotion link