Taste sensitivity, nutritional status and metabolic syndrome : implication in weight loss dietary interventions

AIM: We investigated the relationship between taste sensitivity, nutritional status and metabolic syndrome and possible implications on weight loss dietary program. METHODS: Sensitivity for bitter, sweet, salty and sour tastes was assessed by the three-Alternative-Forced-Choice method in 41 overweight (OW), 52 obese (OB) patients and 56 normal-weight matched controls. OW and OB were assessed also for body composition (by impedence), resting energy expenditure (by indirect calorimetry) and presence of metabolic syndrome (MetS) and were prescribed a weight loss diet. Compliance to the weight loss dietary program was defined as adherence to control visits and weight loss ≥ 5% in 3 mo. RESULTS: Sex and age-adjusted multiple regression models revealed a significant association between body mass index (BMI) and both sour taste (P < 0.05) and global taste acuity score (GTAS) (P < 0.05), with lower sensitivity with increasing BMI. This trend in sensitivity for sour taste was also confirmed by the model refitted on the OW/OB group while the association with GTAS was marginally significant (P = 0.06). MetS+ subjects presented higher thresholds for salty taste when compared to MetS- patients while no significant difference was detected for the other tastes and GTAS. As assessed by multiple regression model, the association between salty taste and MetS appeared to be independent of sex, age and BMI. Patients continuing the program (n = 37) did not show any difference in baseline taste sensitivity when compared to drop-outs (n = 29). Similarly, no significant difference was detected between patients reporting and not reporting a weight loss ≥ 5% of the initial body weight. No significant difference in taste sensitivity was detected even after dividing patients on the basis of nutritional (OW and OB) or metabolic status (MetS+ and MetS-). CONCLUSION: There is no cause-effect relationship between overweight and metabolic derangements. Taste thresholds assessment is not useful in predicting the outcome of a diet-induced weight loss program.