Introduction Non-communicable diseases are the leading causes of premature mortality worldwide. Both genetic predispositions and environmental exposures affect disease risk. Biobanks have increased understanding of genetic predictors of these diseases, but environmental influences are expected to be larger. Individuals also create their own environments and lifestyles based on genetically regulated preferences, leading to gene-environment interactions that require large datasets to study. Biobanks may lack sufficient lifestyle and environmental data, which limits their use for studies targeting disease prevention. We present a protocol for a biobank-recall study (BioRecall) to collect lifestyle and environmental exposures and combine these with genotypes, biological samples and clinical outcomes. Central Finland Biobank donors with a diagnosis of type 2 diabetes will be invited to participate in the pilot study. Methods and analysis All previously genotyped donors of the Central Finland Biobank, diagnosed with type 2 diabetes, and consenting to recalls will be invited to complete an electronic questionnaire on the MyBiobank portal. According to the preliminary feasibility assessment, there are 1,386 suitable candidates. The questionnaire includes validated questions on current and past lifestyles, anthropometrics, weight loss history, health, symptoms, work characteristics, emotional state, and residential environment. Postcode information will allow spatial environmental data to be added. Genotype and related clinical data will be provided to the study in accordance with the Finnish Biobank Act and combined with questionnaire data. Ethics and open data The Human Sciences Ethics Committee of the University of Jyvaskyla has delivered a favourable statement about the study protocol (1671/13.00.04.00/2023). Central Finland Biobank approved the research plan (no: BB24-0333-A01). Data collected will be returned to the Central Finland Biobank for research purposes with participant's consent. Permission for data usage can then be applied through standard protocols of the Fingenious service (www.fingenious.fi). If successful, the study will be expanded to other donors and Finnish biobanks.

The authors have declared no competing interest.

This project is supported by the JYU.Well strategic funding received from the University of Jyvaskyla (to ES) and the research infrastructure funding received from the Research Council of Finland (grant number: 358894 to ES) as part of the BBMRI.fi consortium. ES is supported by the Research Council of Finland (grant numbers: 341750, 346509, and 361981), Juho Vainio Foundation and Paivikki and Sakari Sohlberg Foundation. SR and TF are supported by Juho Vainio Foundation. MR is supported by the Research Council of Finland (grant number: 330185). KA is partially supported by the European Regional Development Fund through the Regional Council of Northern Savo (No. A80407) for the development of FOODNUTRI infrastructure and by the Joint Action on Cardiovascular Diseases and Diabetes (JACARDI), funded by the EU4Health Programme (Grant Agreement No. 101126953).

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The Human Sciences Ethics Committee of the University of Jyvaskyla has delivered a favourable statement about the study protocol (1671/13.00.04.00/2023). Central Finland Biobank approved the research plan (no: BB24-0333-A01).

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

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I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes

The Finnish biobank data can be accessed through the Fingenious services (https://site.fingenious.fi/en/) managed by Finnish biobank cooperative. Novel physical activity questions developed in the project as well as their REDCap implementation are available from the corresponding authors upon a reasonable request. The HDI questionnaire is available and administered by the Finnish Institute for Health and Welfare (THL). Developed feedback based on the HDI can be obtained upon a reasonable request from the FOODNUTRI project (KA).