Relationship of 6-n-propylthiouracil Taste Intensity and Chili Pepper Use with Body Mass Index, Energy Intake, and Fat Intake Within an Ethnically Diverse Population

Background: One of the weight-loss strategies that has attracted attention is the use of spicy foods. It has been suggested that spicy food preference is related to a genetically predetermined sensitivity to the bitter compound 6-n-propylthiouracil (PROP).

Objective: Our aim was to examine the relationship of PROP taste intensity and hot chili pepper use with body mass index (BMI), energy intake, and fat intake.

Design: This study utilized a cross-sectional design.

Participants/setting: The sample included 350 subjects (154 male, 196 female) ages 18 to 55 years living in the New York City area.

Main Outcome Measures: BMI was calculated by measuring weight and height, and the sensitivity to PROP was evaluated using the PROP filter paper method. Subjects also rated the frequency of usage and preference for hot chili pepper using a chili pepper questionnaire. Their daily energy and fat intake were assessed using a food frequency questionnaire.

Statistical Analyses Performed: An independent sample t-test compared subject characteristics between groups based on sex, PROP status, and hot chili pepper user status for the continuous variables, and the χ(2) test was used for categorical variables. One-way analysis variance examined the differences in subject characteristics across four ethnicities. To predict BMI, energy intake, and fat intake, multiple linear regression models were fit with the covariates of age, sex, ethnicity, chili pepper score, and PROP mean.

Results: The values for BMI, energy intake, and fat intake of PROP tasters were significantly lower than those of PROP nontasters (P=0.03, P<0.001, and P<0.001, respectively). The energy intake of chili pepper nonusers was significantly lower than that of chili pepper users (P=0.02), while there was no significant difference in fat intake between chili pepper users and nonusers.

Conclusions: This study suggests that PROP taste sensitivity contributes more to the prediction of energy and fat intake than chili pepper use.