Development of the Leeds Food Preference Questionnaire in Spanish

The Leeds Food Preference Questionnaire (LFPQ) is a computer-based task for measuring reward responses (liking/wanting) and preferences for images of food. There are no cultural adaptation studies for the Spanish population to date in order to address its validity and repeatability in a test-retest design. The present study aim to develop a Spanish version of the LFPQ (ES-LFPQ), examine its outcomes under fasted and fed states; and test its reproducibility after one week.

An online survey containing foods that were either low-fat sweet, high-fat sweet, low-fat savoury or high-fat savoury was first conducted among a sample of 96 Spanish adults (60.4 % women) to develop and validate a culturally appropriate food image database. 50 participants (25 men and 25 women) will participate in two identical trials where they will completed the ES-LFPQ under fasted and fed states (immediately after a standardised meal), at least one week apart.

• Standardized meal (Other): Assessment of the validity of the ES-LFPQ: Each participant will complete the ES-LFPQ in before (fasted state) and after a standardized meal (fed state). Evaluation of the reproducibility of the ES-LFPQ: With at least one week of difference between tests, each participant will repeat the same protocol performed in the previous visit and under the same conditions.

Primary outcomes

• Explicit liking [60 minutes]: The sensory pleasure elicited by contact with food. Measured with 0 to 100-mm visual analogue scale in response to the question "How pleasant would it be to taste some of this food now?" where 0 means "Not at all" and 100 means "Extremely"
• Explicit wanting [60 minutes]: The motivation to consume a specific food manifesting explicitly (conscious and subjective). Measured with 0 to 100-mm visual analogue scale in response to the question "How much do you want some of this food now?" where 0 means "Not at all" and 100 means "Extremely"
• Implicit wanting [60 minutes]: The motivation to consume a specific food manifesting implicitly (unconscious). Measured by punctuation on questionnaire ES-LFPQ. The score assigned to a specific food category based on a forced choice between pairs of food options and taking into account reaction time, in response to the question "Which food do you desire to consume the most at present?". A positive score indicates a greater preference for a given food category relative to the alternatives in the task and a negative score indicates the opposite. A score of zero would indicate that the category is equally preferred.
• Relative preference [60 minutes]: The preference of a food in comparison with another food. Measured by punctuation on questionnaire ES-LFPQ. The score assigned to a specific food category based on a forced choice between pairs of food options in response to the question "Which food do you desire to consume the most at present?". A positive score indicates a greater preference for a given food category relative to the alternatives in the task and a negative score indicates the opposite. A score of zero would indicate that the category is equally preferred.
• Fat appeal bias [60 minutes]: Bias scores for food fat content (high or low) computed by subtracting the mean low-fat scores from the mean high-fat scores. Positive values indicate a preference for high-fat, negative values indicate a preference for low fat and a score of 0 indicates an equal preference between fat content.
• Taste appeal bias [60 minutes]: Bias scores for food taste (savoury or sweet) computed by subtracting the mean savoury scores from the mean sweet scores. Positive values indicate a preference for sweet foods, negative values indicate a preference for savoury foods and a score of 0 indicates an equal preference between taste categories

Secondary outcomes

• Hunger [60 minutes]: The subjective sensation described as the primary motivation to eat. Measured with 0 to 100-mm visual analogue scale in response to the question "How hungry do you feel now?" where 0 means "Not at all" and 100 means "Extremely"
• Fullness [60 minutes]: The degree of satisfaction and/or fullness following food consumption. Measured with 0 to 100-mm visual analogue scale in response to the question "How full do you feel now?" where 0 means "Not at all" and 100 means "Extremely"

Sex: All, ages: 18 Years to any, accepts healthy volunteers

Inclusion Criteria:

* Being able to understand instructions, programs and questionnaires.
* Being able to recognize the foods presented in at least 4 of the 5 photographs available for each category that make up the ES-LFPQ.
* Living in Spain for at least 2 years

Exclusion Criteria:

* Being intolerant, allergic and/or having an aversion to the foods contained in the standardized meal.
* Never eat the foods presented in at least 4 of the 5 photographs available for each category that make up the ES-LFPQ