Umami Taste Perception
Conditions
Brief summary
The purpose of this study is to determine how repeated dietary exposure to umami taste affects umami taste perception, hedonics, food preferences, and satiety. Healthy adult subjects will consume a low glutamate vegetable broth daily for one month, where the experimental group's broth is supplemented with the umami-rich stimuli of monosodium glutamate (MSG) and the control group's low glutamate broth is matched for sodium (NaCl). The investigators hypothesize that repeated dietary exposure to umami taste will: 1. diminish umami suprathreshold intensity perception and hinder the ability to discriminate varying MSG concentrations 2. decrease liking of umami-rich foods and shift preferences upwards towards more intense umami stimuli 3. decrease satiation and decrease the satiating effect of a test meal
Interventions
Subjects eat normal diet and consume 8 ounces of vegetable broth with added MSG one time per day for 1 month
Subjects eat normal diet and consume 8 ounces of low glutamate vegetable broth without MSG (sodium-matched with NaCl) one time per day for 1 month
Sponsors
Study design
Eligibility
Inclusion criteria
* Have normal sense of taste and smell (self-report) * Likes soups or broths (self-report) * Able to report to study site daily (self-report)
Exclusion criteria
* Restrained eater (score \> 12 on restrained eating subscale from Three Factor Eating Questionnaire) * BMI \< 18 or \> 25 kg/m2 (self-report) * Vegan (self-report) * Hypertensive or on low-sodium diet (self-report) * Allergic or sensitive to MSG (self-report)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in umami taste intensity perception | 1 month (at baseline and post intervention) | Subjects rate the umami intensity of aqueous solutions and foods on the general Labeled Magnitude Scale before and after a month-long dietary supplementation to determine how perception changes with repeated exposure to umami taste |
| Change in umami taste discrimination | 1 month (at baseline and post intervention) | Subjects rank solutions of varying umami intensity before and after a month-long dietary supplementation to determine how perception changes with repeated exposure to umami taste |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in liking and wanting of high protein foods | 1 month (at baseline and post intervention) | Subjects complete the Leeds Food Preference Questionnaire before and after a month-long dietary supplementation to determine how explicit liking and implicit wanting of high-protein foods changes with repeated exposure to umami taste |
| Change in umami liking and preference | 1 month (at baseline and post intervention) | Subjects rate liking and preference in a variety of umami-rich foods before and after a month-long dietary supplementation to determine how liking and preference of umami-rich foods changes with repeated exposure to umami taste |
| Change in satiation | 1 month (at baseline and post intervention) | Subjects consume a test meal and the amount of food eaten is measured before and after a month-long dietary supplementation to determine how satiation from a test meal differs after repeated exposure to umami taste |
| Change in satiety | 1 month (at baseline and post intervention) | Subjects consume a test meal and rate appetite sensations on a visual analog scale throughout the test meal before and after a month-long dietary supplementation. A satiety quotient will be derived from these values with the formula: Satiety Quotient = (rating pre-eating episode-rating post-eating episode) / (intake of eating episode) to determine how satiety changes with repeated exposure to umami taste |
Other
| Measure | Time frame | Description |
|---|---|---|
| Weight | 1 month (at baseline and post intervention) | Body weight (kilograms) will be measured with standard procedures and equipment. Using this information, BMI will be calculated with the formula: BMI=\[kg/m\]2 to ensure that BMI does not change with repeated exposure to umami taste |
| Height | 1 month (at baseline and post intervention) | Body height (centimeters) will be measured with standard procedures and equipment. Using this information, BMI will be calculated with the formula: BMI=\[kg/m\]2 to ensure that BMI does not change with repeated exposure to umami taste |
| Habitual glutamate consumption | 1 month (at baseline and post intervention) | Subjects complete the National Cancer Institute's monthly diet history questionnaire to estimate habitual glutamate consumption. Baseline habitual glutamate consumption, in addition to gender, will be assessed as effect modifiers in the analysis. |