Healthy Eating and Active Living (HEAL): A Single-Arm Feasibility Trial of a Multimodal Lifestyle Intervention on Brain, Metabolic, and Behavioral Health

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.