Blunted orosensory perception of lipids during obesity: myth or reality?

Obesity is now considered as a disease requiring treatment and prevention efforts by reason of severe associated co-morbidities and its growing prevalence in worldwide population. Although origin of this "epidemic" situation is clearly multifactorial, recent changes in our life-style especially about our food supply with an easy access to low-cost energy-dense foods seem to play a significant causal role in this phenomenon. Studies also report that obesity is frequently associated with a preferential consumption of high palatable foods rich in fat and sugar. Since these foods are pleasant and have high hedonic quality, this obesogenic eating behavior change raises the possibility of an alteration of orosensory perception system as a consequence of obesity. This hypothesis has led to a recent literature on the relationship between obesity and sensory sensitivity, known to play a significant role in the food choice. The purpose of this mini-review, focused on the orosensory perception of dietary lipids (i.e. taste of fat), is to provide a short overview of what is observed in food-induced obese rodents as compared to what is found in patients with obesity. It tries to answer to the following basic question: is obesity associated with a loss of orosensory sensitivity to dietary lipids that leads to obesogenic food choices? L'obesite est desormais consideree comme une maladie en tant que telle necessitant un traitement et une prevention specifiques en raison des comorbidites severes qui lui sont associees et de sa prevalence croissante dans la population mondiale. Bien que l'origine de cette situation << epidemique >> soit clairement multifactorielle, les changements recents de notre mode de vie, notamment de notre approvisionnement alimentaire avec un acces aise a des aliments peu chers mais a forte densite energetique, semblent jouer un role causal important dans ce phenomene. Des etudes rapportent egalement que l'obesite est frequemment associee a une consommation preferentielle d'aliments hautement palatables, riches en graisses et en sucres. Comme ces aliments sont agreables en bouche, ce comportement alimentaire obesogene suggere l'existence d'une alteration du systeme de perception orosensorielle des aliments liee a l'etat d'obesite. Cette hypothese est a l'origine d'etudes recentes sur la relation entre l'obesite et la gustation, connue pour jouer un role important dans le choix alimentaire. L'objectif de cette mini-revue, centree sur la perception orosensorielle des lipides alimentaires (gout du gras), est de fournir un bref apercu de ce qui est connu chez les rongeurs rendus obeses par voie alimentaire et ce qui est observe chez les patients souffrant d'une obesite. Elle tentera de repondre a une question basique : l'obesite est-elle associee a une perte de sensibilite orosensorielle aux lipides alimentaires conduisant a des choix alimentaires obesogenes ?