Socio-ecological influences on adolescent (aged 10–17) alcohol use and linked unhealthy eating behaviours: protocol for a systematic review and synthesis of qualitative studies

Abstract Background Excess body weight and risky alcohol consumption are two of the greatest contributors to global disease. Health behaviours cluster in adolescence and track to adulthood. Very little is known about similar and contrasting influences on young people’s eating behaviours and alcohol use. Whilst there are bodies of literature which explore the influences on young people’s eating behaviour and alcohol consumption respectively, no qualitative studies have been identified with an explicit and concurrent focus on adolescent eating behaviours and alcohol consumption. This review will identify and synthesise qualitative research evidence to provide insight into common underlying factors which influence alcohol use and unhealthy eating behaviours amongst young people aged 10–17. This will involve bringing together two separate bodies of literature to enable analysis and comparison across two associated fields of study. Methods We will conduct searches in MEDLINE, Scopus, PsycINFO, Sociological Abstracts (via ProQuest social science premium collection), CINAHL, ERIC, IBSS (via ProQuest social science premium collection), ASSIA (via ProQuest social science premium collection), and Web of Science Core Collection. Studies reporting primary data of any qualitative design, for example, ethnographic studies, studies that used a phenomenological or grounded theory approach, or participatory action research will be included in the review. Database searches will be supplemented with searches of Google Scholar, hand searches of key journals, and backward and forward citation searches of reference lists of identified papers. Search records will be independently screened by two researchers, with full text copies of potentially relevant papers retrieved for in-depth review against the inclusion criteria. Reporting of identified studies will be assessed using the Critical Appraisal Skills Programme (CASP) Qualitative Research Checklist. GRADE-CERQual will also be used to assess confidence in the findings arising from our review. Qualitative synthesis will involve three core phases: line-by-line coding of findings; development of descriptive themes; and development of analytical themes. Findings from papers will be examined for overlaps, similarities and differences. Discussion This synthesis will interpret individual studies by identification of second-order constructs (interpretations offered by the original researchers) and third-order constructs (development of new interpretations beyond those offered in individual studies) by way of the development of a ‘model structure’ of shared influences upon both unhealthy eating behaviours and alcohol use. It is anticipated that this ‘model structure’ will aid subsequent co-design and piloting of a future intervention to help reduce health risk and social inequalities due to excess weight gain and alcohol consumption. Systematic review registration CRD42017060624 .