Gustatory thresholds and obesity: a comparative study of five main tastes.

Background: Obesity is an important public health concern, which has dramatically grown in the last decades. Taste sensation determines food preferences and could contribute to obesity. Considering the conflicting results about the association of gustatory threshold and overweight/obesity status of individuals, this study designed to compare gustatory threshold of five main tastes (sweet, umami, salty, bitter, and sour) among individuals with overweight/obesity and with a normal BMI.

Methods: In this case-control and population-based study, 100 adults participated, divided into two equal number of normal and overweight/obese groups. To measure gustatory threshold of sweet, umami, salty, bitter, and sour tastes, solutions of sucrose, monosodium glutamate, sodium chloride, quinine hydrochloride and citric acid were prepared respectively. Three millimeters of each solution was dropped on the right side of the posterior tongue, and the same volume of distilled water was dropped on the left side. The concentration at which the participant perceived the taste was considered the gustatory threshold. The data was analyzed in SPSS software version 22 with the Mann-Whitney test and Spearmen correlation coefficient.

Results: No statistically significant differences were observed between the gustatory thresholds of the five main tastes among participants with normal BMI and with overweight/obesity. Moreover, among the numerical value of BMI and perceived concentrations of each of the tastes, no association was found (p value > 0.05).

Conclusions: According to the findings obtained from this study, no significant statistical difference in gustatory threshold of five main tastes was observed among individuals with overweight/obesity and normal weight.