Summaries are in Finnish for attendees are availabe and reviewed in ethical approcval process

Abstract in English Background: Physical and cognitive demands on military service are ever-increasing in the Finnish Defense Forces. The University of Helsinki and Center for Military medicine are conducting a pioneering research initiative known as the NutFinForce study. This innovative project aims to evaluate the impact of a digital delivered lifestyle intervention on the defense performance of Finnish conscripts.

Objective and Scope: The primary objective of the study is to enhance the physical and cognitive performance through targeted nutritional and lifestyle digital intervention. Equally we will assess the feasibility, acceptability, and cost-effectiveness of personalized digital health coaching and support for adopting healthier dietary and lifestyle habits. The aim is to foster long-term health benefits for public health and to improve national defense capability that isa a cumulative outcome for optimizing health of reserve.

Methodology: The intervention leverages a sophisticated digital platform that offers personalized guidance and support to participants. Special attention is paid to target group needs and military service as an environment in intervention design. Platform is accessible before, during, and after military service, ensuring opportunities for longitudinal and sustainable engagement and support. A large-scale implementation includes two sequential brigades (N=5000). Data collection will be conducted through the digital application platform used in the intervention.

Expected Outcomes: Key outcomes will include improvements in nutrition and eating patterns and perceived physical performance as swell as perceived cognitive sharpness/performance as a variable for outcome. The study will evaluate the cost-effectiveness of the intervention, providing important data for future policy and practice within the Finnish Defense Forces and NATO ally military forces.

Implications for Military Policy and Public Health: The findings from the NutFinForce study will have significant implications for military policy and practice. By demonstrating the benefits of digital health interventions that positively influence daily lifestyle behavior choices, the research could inform the development of future nutritional and lifestyle programs within the military. Moreover, the study's insights may have broader public health implications, highlighting the potential of digital health platforms to promote healthier behaviors and improve population health.

Inclusion Criteria:

• The participants for the intervention are recruited along with the invitation process of the Finnish Defense Forces in such a way that it does not interfere with the actual goal itself: attending the military service.

Attendance for the intervention, suspension of the intervention or not attending is not known by the Defense Forces and does not influence terms of service

Exclusion Criteria:

• Not attending the military service

The conscription of the Finnish Defense Forces is carried out nationally at the location specified in the conscription letter. For many years already, the conscripts will have had a digital intervention available for developing their physical fitness and an invitation to a phone application

All data will be managed according to a Data Management Plan compiled at the start of the project and divided into four steps: Data Collection, Storage and Documentation, and Data Sharing. All steps of the Data Management Plan that is following the data management protocols of the University of Helsinki