Indigenous Mayan-Yucatecan communities in Mexico have a high prevalence of chronic non-communicable diseases (NCDs) such as diabetes, hypertension, obesity and rheumatic diseases (RMDs). According to the syndemic theory, these diseases combined with social, economic and cultural factors affect the quality of life. The aim of this protocol is to describe the methodological process to create, implement and evaluate a Syndemic-Based Care Model (SCM), using a Community Based-Participatory Research (CBPR) strategy in three Mayan-Yucatecan communities.

This is a convergent mixed-methods protocol. The quantitative component is a before-after study, and the qualitative component is an ethnographic study. The intervention will be a SCM co-constructed with Mayan communities based on their particular needs and aiming for reduction of the negative impact of NCD/RMD through a multidisciplinary approach. We will follow four phases of the CBPR: (1) situational analysis, through community censuses and semistructured interviews to understand the prevalence of NCDs and the syndemics in these communities; (2) co-construction of the elements of a SCM based on the health priorities identified by researchers, community members and healthcare workers; (3) implementation of this SCM and (4) evaluation of the SCM through (1) statistical analyses involving the construction of a syndemic index through stepwise logistic regression of the normalised and standardised key clinical, social and economic variables; interval and ratio variables will be normalised by their z-score and categorical variables will be one-hot encoded; similarity and social networks analysis with clustering to identify syndemic subpopulations; and cost-effectiveness and cost-utility analyses using Markov modelling and (2) narrative and thematic qualitative analysis of the SCM’s implementation and impact on community members’ health, function and quality of life.

Research ethics boards of participant institutions approved this research protocol. This project will be presented to municipal authorities, community meetings and community leaders for observation and acceptance. For people who wish to participate, informed consent will be provided written and verbally in Spanish or Mayan-Yucatecan according to the participant preferences, and it can be signed by either autograph or fingerprint. The results of this research will be disseminated to various groups: (a) local and regional authorities of the Mexican health system and municipal authorities; (b) the participating communities will be informed in an assembly of the results and (c) academic dissemination will be done through publications in public science journals and institutional press releases and will also be presented at national and international congresses or symposia.

Amyotrophic lateral sclerosis (ALS) is a devastating illness that leads to muscle weakness and death usually within around 3 years of diagnosis. People with ALS (pwALS) often lose weight due to raised energy requirements and symptoms of the disease presenting significant challenges to taking adequate oral diet, with those who lose more weight being at a greater chance of earlier death. There is also some evidence to suggest that a higher calorie diet may benefit the disease course in pwALS, but further research is needed.

Two armed, parallel group, superiority, open labelled, randomised controlled trial, with internal pilot, to assess the effectiveness of an early high calorie diet on functional outcomes in ALS, comprising two treatment arms: (1) standard care, (2) standard care with additional active management using the OptiCALS complex intervention to achieve a high calorie diet (initially randomised 1:1, then 1:2 following a protocol amendment). Using a food first approach, pwALS will be encouraged and supported to follow a diet that meets an individualised calorie target from food before prescribing oral nutritional supplements. 259 pwALS will be recruited from up to 20 ALS centres across the United Kingdom and Ireland and followed up for a period of 12 months. Primary outcome is functional change measured over 12 months, using the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale. Secondary end points include measures of functional health, quality of life, calorie intake and weight, as well as time to gastrostomy and survival. A health economic analysis and process evaluation will also be undertaken. Participant recruitment is expected to complete in September 2025, and participant follow-up is expected to complete in September 2026. The results of this study are expected in March 2027.

The trial was approved by Greater Manchester—North West Research Ethics Committee, reference 20/NW/0334 on 8 September 2020. We will publish the study findings in peer-reviewed academic journals and present at local, national and international conferences where possible.

ISRCTN30588041.