Live Long, Heart Strong: A Digital Nutrition Intervention for Emerging Adults

Live Long, Heart Strong (LLHS) is a theory-guided, digital twin-supported nutrition intervention designed to promote cardiovascular health behaviors among emerging adults (18-25 years). Developed using a human-centered design approach and informed by Social Cognitive Theory, the intervention incorporates personalized nutrition education, interactive learning activities, goal setting, self-monitoring, quizzes, youth-informed educational videos, tailored feedback, reminders, and gamification to support healthy eating behaviors and improve dietary quality. In this pilot randomized controlled trial, participants will be randomly assigned to either the LLHS intervention or an active comparator consisting of a static, non-personalized digital nutrition education toolkit containing similar evidence-based educational content without personalization, interactivity, or behavioral support features. The study will evaluate implementation outcomes (feasibility, usability, acceptability, and appropriateness), changes in psychosocial and behavioral outcomes related to healthy eating, and preliminary cardiovascular-related health indicators. Findings will inform continued refinement of the LLHS intervention and the design of a future fully powered efficacy trial.

Participants are eligible if they: * Are 18 to 25 years old. * Are able to read and understand English. * Reside in Texas at the time of the study. * Own a smartphone with internet access. * Are willing to be randomized to either study group, attend baseline and post-intervention study visits, and complete study assessments. * Provide informed consent. Participants are excluded if they: * Are younger than 18 years or older than 25 years. * Are unable to read or understand English. * Do not have reliable access to a smartphone with internet access. * Are unable or unwilling to provide informed consent. * Are currently participating in another nutrition, weight management, or cardiovascular health intervention study that could affect study outcomes. * Have a medical condition or dietary restriction that requires a highly specialized diet and would make the general LLHS nutrition content inappropriate without clinical supervision.