Lifestyle interventions combining nutrition, physical activity, and behavioral strategies are increasingly recognized for improving metabolic and psychological health, yet their translation into real-world settings remains limited. Key implementation factors such as feasibility, adherence, intervention fidelity, and the integration of complex assessment modalities are often underreported, despite being essential for scaling and clinical application.

The Healthy Eating and Active Living (HEAL) study is a prospective, single-arm feasibility trial evaluating a structured, multimodal lifestyle intervention within a university research environment. The 12-week program integrates supervised progressive resistance training and structured nutritional guidance, delivered through existing infrastructure including the Center for Brain and Health, the Public Health Research Center, on-campus fitness facilities, and digital dietary monitoring tools. The exercise component consists of twice-weekly supervised, machine-based resistance training with standardized progression, while the nutritional component includes four weeks of meal provision followed by guided self-management.

Participants complete a multimodal assessment battery at baseline, post-intervention, and 12-week follow-up, including body composition, blood biomarkers, gut microbiome analysis, fitness testing, wearable-based activity and sleep monitoring, self-reported measures, and resting-state functional magnetic resonance imaging (fMRI).

The primary objective is to assess feasibility, including recruitment, retention, adherence, intervention fidelity, safety, acceptability, and data completeness. Secondary analyses explore pre-post changes in physiological, behavioral, and neuroimaging outcomes to inform future study design. The study is not powered to assess clinical efficacy. Findings will inform the design of larger trials and the application of the HEAL framework in clinical populations.

Lifestyle-related disorders, including metabolic dysfunction, mental health conditions, and neurodegenerative processes, are increasingly recognized as multifactorial in origin, involving complex interactions between behavior, physiology, and environmental exposures. Interventions targeting diet, physical activity, and behavioral patterns have shown promise in improving these outcomes. However, despite growing evidence for their effectiveness, the implementation of comprehensive lifestyle interventions in real-world settings remains limited. Many studies focus on efficacy under controlled conditions but provide insufficient detail on feasibility, adherence, intervention fidelity, and operational demands, all of which are critical for translation into scalable models.

The Healthy Eating and Active Living (HEAL) study was developed as a translational, multidisciplinary lifestyle intervention embedded within a university research environment. The primary aim of the study is not to evaluate clinical efficacy, but to determine whether a structured, multimodal intervention can be delivered with sufficient feasibility, adherence, and operational fidelity to justify progression to larger trials and clinical applications.

This study is designed as a prospective, single-arm feasibility trial conducted over 12 weeks. The intervention integrates supervised progressive resistance training with structured nutritional guidance and incorporates a comprehensive, multimodal assessment battery. The program is delivered using existing institutional infrastructure, including the Center for Brain and Health (CBH), the Public Health Research Center (PHRC), the Core Technologies Platform (CTP), and on-campus fitness facilities. This setting allows evaluation of the intervention under conditions that reflect real-world implementation, rather than highly controlled laboratory environments.

A central design feature of HEAL is the deliberate standardization of its core components to ensure reproducibility and scalability. The exercise component consists of supervised, machine-based resistance training performed twice weekly in 60-minute sessions. Each session follows a fixed sequence of exercises targeting major muscle groups, including leg press, chest press, seated row, glute drive, lat pulldown, walking lunges, and a core exercise. Following a brief familiarization phase, progression is guided by predefined overload criteria, requiring incremental increases in resistance when participants are able to complete target repetitions with correct form. This standardized structure minimizes variability in delivery, facilitates monitoring of adherence and fidelity, and supports consistent implementation across participants.

The nutritional component is designed to combine structured support with gradual transition to self-management. During the initial four weeks, participants receive prepared meals five days per week, tailored to individual maintenance energy requirements calculated using established predictive equations. Meals follow a standardized macronutrient distribution and emphasize minimally processed, nutrient-dense foods with high dietary fiber content. Participants select meals from a predefined menu, ensuring both adherence to nutritional targets and individual preference. Following the meal-provision phase, participants are guided to maintain similar dietary patterns independently for the remaining eight weeks. Dietary intake is monitored using Intake24, an online 24-hour dietary recall system, administered at baseline, post-intervention, and follow-up.

To evaluate feasibility and the operational burden of integrating diverse outcome measures, the study incorporates a comprehensive multimodal assessment battery. Assessments are conducted at baseline (prior to the intervention), immediately post-intervention, and at a 12-week follow-up period. Physiological measures include anthropometry and body composition analysis using bioelectrical impedance. Blood samples are collected to assess metabolic, inflammatory, and lipid biomarkers. Stool samples are obtained for metagenomic analysis of the gut microbiome. Physical fitness is evaluated using a standardized battery including cardiovascular, strength, mobility, and stability tests. Objective activity and sleep data are collected using a wrist-worn wearable device over an eight-day period. Participants also complete validated self-report questionnaires assessing sleep, wellbeing, energy levels, and daily activity patterns. In addition, resting-state functional magnetic resonance imaging (fMRI) is performed to assess brain network connectivity and to evaluate the feasibility of incorporating neuroimaging within a lifestyle intervention.

The primary outcomes of this study relate to feasibility rather than clinical effectiveness. These include recruitment rates, retention across the intervention period, adherence to supervised exercise sessions, fidelity to the prescribed progression protocol, adherence to nutritional guidance, participant acceptability, safety, and completion rates for each component of the assessment battery. Safety is monitored continuously, with documentation of adverse events, including musculoskeletal complaints or nutrition-related issues. Acceptability is assessed qualitatively through participant feedback regarding burden and overall experience.

Secondary outcomes are exploratory and include descriptive changes in physiological, behavioral, and neuroimaging measures across timepoints. These analyses are not intended to establish efficacy but to identify potential signals, inform outcome selection, and support sample size estimation for future studies.

The HEAL study also serves as a foundational model for subsequent applications of the intervention framework. In particular, it informs the development of the HEAL-MS program, which adapts the intervention for individuals with multiple sclerosis within a clinical context. By establishing that the intervention can be delivered with high adherence, acceptable participant burden, and operational feasibility, this study provides essential implementation data to guide future translational and clinical research.

In summary, the HEAL study is designed to address a key gap in lifestyle intervention research by focusing on feasibility, implementation, and scalability within a real-world setting. The integration of standardized intervention components with a comprehensive multimodal assessment framework allows evaluation not only of participant engagement but also of the logistical and operational requirements necessary for broader application. Findings from this study will inform the refinement of the intervention protocol and support progression to larger-scale trials and clinical populations.

Inclusion Criteria:

• Adults aged 18 to 65 years
• Able to participate in moderate-intensity supervised resistance training
• Willing to comply with the 12-week intervention and associated assessments
• Able to provide biological samples (blood and stool) and complete behavioral assessments
• Able to provide written informed consent

Exclusion Criteria:

• Medical conditions contraindicating moderate resistance training (e.g., uncontrolled cardiovascular, respiratory, or musculoskeletal conditions)
• Current pregnancy or planned pregnancy during the study period
• Participation in another structured lifestyle, nutrition, or exercise intervention during the study period

Individual participant data (IPD) will not be made publicly available due to the sensitive nature of the multimodal data collected, including neuroimaging, genetic (metagenomic), and detailed physiological and behavioral information, which may increase the risk of participant re-identification. In addition, data sharing is subject to institutional policies and ethical approvals governing data collected within a university research setting. De-identified data may be made available upon reasonable request, subject to appropriate data use agreements and ethical approval.

Although the study is conducted as an open-label, single-arm intervention, analysis of outcome measures is performed by researchers blinded to the timing of assessments. This includes blood biomarkers, stool-based metagenomic data, neuroimaging (fMRI) data, and behavioral questionnaire outcomes. Blinding is maintained during data processing and analysis to reduce potential bias in interpretation of results.