Spain worked on a project titled “Transitioning to sustainable diets: a tool to identify people’s barriers and motivators for following a sustainable diet”.

Júlia Muñoz-Martínez led the development and validation of a questionnaire to identify the motivators and barriers to following a sustainable diet among Spanish citizens sensitive to socioeconomic differences.

The tool is called the SALSA questionnaire (Sustainability and Healthy Diets, as its acronym in Spanish) and intends to provide the means for dietitians and other stakeholders involved in public health, for the development interventions aiming to equitably promote healthy and sustainable diets.

The process was to identify all the barriers and facilitators for following a sustainable diet among different socioeconomic groups in Barcelona to develop a first draft of SALSA. This was administered to 9 Spanish experts in the fields of sustainability, nutrition (including a member from the Spanish NDA), psychology, and sociology to validate the content. 

By March 2023, the survey pre-test was done with citizens from the city of Barcelona and its urban surroundings through 3 focus group discussions and 5 individual interviews.

Between April and June, they administered the online survey to a sample of more than 700 citizens across Spain.  They then conducted data cleaning and psychometric analysis (item reduction, extraction of factors, test of dimensionality, test of reliability, and test of validity).  Exploratory Factor Analysis revealed four final dimensions of the SALSA questionnaire, which corresponded to personal factors, external factors, sociocultural factors, and consumption of animal and plant-based protein. These dimensions were validated through Confirmatory Factor Analysis. 

The final SALSA questionnaire investigates the barriers and facilitators for people to adhere to a sustainable and healthy diet through a set of 27 questions, grouped into four dimensions (listed above). Respondents are asked to rate their level of agreement on a scale from 1 to 5, with 1 indicating ‘completely disagree’ and 5 indicating ‘completely agree.’ This tool is a step forward towards the promotion of SHD as it can be applied in multiple scenarios. It could be used in the planning and assessment of interventions with such an aim, as well as by dietitians in one-to-one consultations at the individual level.

In February 2025, an open-access article was published: The SALSA Questionnaire: creation and validation of a tool to assess people’s self-perceived barriers and facilitators to follow a sustainable and healthy diet (2025 Feb)