New data findings show the Optimal Weight 5 & 1 plan® delivers metabolic health benefits beyond weight loss, helping preserve 98% of lean mass¹

9 out of 10 Americans are metabolically unhealthy, which is an underlying driver of some of the most serious age-related health challenges of our time ²

With more than 90% of U.S. adults classified as metabolically unhealthy¹, the silent crisis of metabolic dysfunction continues to escalate. This condition can be linked to a range of challenges, including being overweight and having difficulty maintaining energy, vitality and long-term health and wellbeing. To address this issue, Medifast, the 40+ year old health and wellness company known for its science-backed, coach-guided lifestyle system, is reinforcing its commitment to advancing metabolic health through its innovative, clinically supported plans.

New Findings: Preserving Lean Mass, Driving Healthier Outcomes

Analysis of biobank data and a review of thousands of data points from the company’s clinical trial revealed a breakthrough finding: individuals on the company’s 5 & 1 plan preserved 98% of lean mass after 16 weeks on the program². Lean mass is critical for optimal metabolic health because it drives basal metabolic rate (BMR), which supports efficient energy use and helps regulate body weight.

"Metabolic dysfunction is more than just a health issue — it’s an invisible epidemic that impacts energy, mood, hormones, and long-term wellness. When metabolic health is off, everything feels off," said Dr. Holly Lofton, Director of the Medical Weight Management Program at NYU Grossman School of Medicine, where she serves as a practicing physician, and a member of Medifast’s Scientific Advisory Board. “Today, many people are living with the daily consequences of metabolic dysfunction, often without even knowing it. It’s not just about the numbers on the scale; it can be about fatigue that keeps you from playing with your kids, weight that feels impossible to manage, or chronic conditions that chip away at your quality of life.”

Scientific Leadership and the Fight Against Metabolic Dysfunction

With more than four decades of experience, Medifast has built a strong foundation of scientific evidence, including more than 30 research studies, 70+ peer-reviewed scientific abstract presentations and publications, and more than 30 peer-reviewed scientific publications. The company continues to invest in advancing science through comprehensive literature reviews, exploratory research, and planned future clinical trials — all designed to advance its understanding of optimal metabolic health.

"As the metabolic health crisis has grown, we’ve gone deeper into both our own clinical trial data and the broader body of research,” said Satya Jonnalagadda, PhD, MBA, RDN, Vice President of Scientific & Clinical Affairs at Medifast. “The evidence is clear: the 5 & 1 Plan doesn’t just promote healthy, quality weight loss. It unlocks a body that works better over time and improves key drivers of metabolic health.³”

Looking Ahead

Jonnalagadda continued, “We’re committed to expanding our scientific and clinical contributions and making an impact on optimal metabolic health. Our approach to helping to reverse the effects of metabolic dysfunction is grounded in science and fueled by support from a coach and community — with the goal of impacting lives at scale.”

Later this month, Medifast will host its Scientific Advisory Board meeting, where a group of distinguished physicians, academic researchers, nutrition, exercise science, and bio-behavioral science experts will explore the latest research on metabolic dysfunction and discuss new opportunities for the company to continue supporting optimal metabolic health. Looking ahead, Medifast will unveil the next phase of its scientific discovery, underscoring its commitment to helping people achieve optimal metabolic health.

About Medifast: Medifast (NYSE: MED) is the health and wellness company offering a simple yet comprehensive approach to weight management and lifestyle change through its science-backed and coach-guided lifestyle system. Designed to address the challenges of metabolic dysfunction, the company’s lifestyle system integrates personalized plans, scientifically developed products and a framework for habit creation — all supported by a unique network of independent coaches. Science is core to the company, marked by an in-house Scientific & Clinical Affairs team and independent esteemed Scientific Advisory Board, 30+ research studies, 70+ scientific abstract presentations and publications, and 30+ publications in peer-reviewed scientific journals. With more than 40 years of clinical heritage, Medifast is addressing the metabolic health crisis through cutting-edge science and community-driven support and remains committed to its mission of offering Lifelong Transformation, Making a Healthy Lifestyle Second Nature®. For more information, visit MedifastInc.com, and follow Medifast on X and LinkedIn.

¹ O'Hearn M, et al. Trends and Disparities in Cardiometabolic Health Among U.S. Adults, 1999-2018. J Am Coll Cardiol. 2022;80(2):138-151. doi: 10.1016/j.jacc.2022.04.046.

² Arterburn LM, et al. Randomized controlled trial assessing two commercial weight loss programs in adults with overweight or obesity. Obes Sci Pract. 2018;5(1):3-14. doi: 10.1002/osp4.312. In a clinical study, individuals on the OPTAVIA 5&1 Plan retained 98% of lean mass at 16 weeks.

³ Cesaro A, et al. Visceral adipose tissue and residual cardiovascular risk: a pathological link and new therapeutic options. Front Cardiovasc Med. 2023;10:1187735. doi: 10.3389/fcvm.2023.1187735

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