Background and objective:
Health literacy (HL) is the degree to which individuals can find, understand, and use information and services to inform health-related decisions and actions for themselves and others, whether at home, at the workplace, in the community, marketplace, healthcare sector, or the political arena. LISA is a cohort study developed in Portugal, which aims to measure HL in the adult population of Leiria, over the next 10 years. As secondary objectives it is intended to characterize anxiety and depression and metabolic risk.

Methods:
LISA is a population-based prospective cohort study. It will collect data on HL through _European Health Literacy Survey _(HLS19-Q12). The study population will be composed by adults (≥ 18 years old) who are non-institutionalized and living in private households in Leiria. The random sample is stratified by gender and age groups. A face-to-face interview will be conducted with the Computer Assisted Personal Interview at baseline. Follow-up will be carried out every 2 years via telephone call. The association between independent variables and health literacy is examined by means of variance analysis with measurement repetition.

Results:
The measuring instruments will allow a diagnosis of the situation in the municipality of Leiria. It will be possible to develop specific strategies and initiatives to promote HL, that will allow each citizen to make an informed decision, and that contribute to better health outcomes, more efficient use of health services, and decrease in health spending.

Conclusion:
The HLS-EU revealed that 47.6% of respondents in Europe had limited HL. Given these issues, it is necessary to train and inform about the disease and what everyone should do to fight it and, above all, prevent it. This is the HL process that should empower citizens with knowledge to make conscious and informed decisions about the promotion of individual and collective health.