Lion Diet Randomized Controlled Trial for IBD and Rheumatoid Arthritis

The Fuller Research Foundation is funding the first randomized controlled trial of the Lion Diet (a plant-free, ruminant-meat-based ketogenic elimination diet) and a broader ketogenic diet for adults with symptomatic inflammatory bowel disease or rheumatoid arthritis. The trial is IRB-approved and led by Dr. Robert Abbott, MD.

What the Lion Diet is

The Lion Diet is a plant-free elimination diet developed by Mikhaila Peterson in 2017. Participants eat only ruminant meat, salt, and water for a sustained period, then reintroduce foods one at a time to identify triggers. It is one of the most restrictive ketogenic elimination protocols in use and has accumulated a substantial body of patient-reported recoveries from autoimmune and inflammatory conditions, particularly inflammatory bowel disease and rheumatoid arthritis. No large randomized controlled trial of the Lion Diet existed before this study.

Why this trial matters

Roughly 50 million Americans have an autoimmune disease, yet there have been almost no large-scale RCTs evaluating dietary intervention as treatment for IBD or RA. Patient-reported remissions on ketogenic and carnivore protocols have accumulated for years without the kind of controlled evidence required to change clinical guidelines, reimbursement decisions, or specialist referral patterns. This trial is designed to produce that evidence.

Trial design

Adults with a physician diagnosis of either inflammatory bowel disease (Crohn's disease or ulcerative colitis) or rheumatoid arthritis are randomized to one of three arms: a ketogenic diet, the Lion Diet (carnivore), or a control diet. Participants follow the assigned protocol for three to six months with structured clinical assessments, validated symptom and quality-of-life questionnaires, periodic laboratory work, and ongoing support from the research team.

Eligibility requires a formal physician diagnosis of IBD or RA, no significant prior ketogenic or carnivore-diet exposure, and willingness to follow the assigned protocol for the trial duration. A $200 one-time enrollment fee covers intake and administration; all lab work and clinical assessments are funded by the Foundation.

Primary and secondary outcomes

The primary outcomes are validated quality-of-life and symptom-burden measures specific to IBD (such as the IBDQ) and RA (such as DAS28 and patient-reported global assessment). Secondary outcomes include inflammatory markers, medication use, and adherence.

Who is running it

The principal investigator is Dr. Robert Abbott, MD, an integrative and functional physician and founder of Resilient Roots Functional and Evolutionary Medicine in Charlottesville, Virginia. Dr. Abbott holds an MD from the University of Virginia and has trained through the Kresser Institute and the Institute for Functional Medicine. The study is funded by the Fuller Research Foundation, a 501(c)(3) nonprofit (EIN 33-3097190) founded by Mikhaila Peterson (also known as Mikhaila Fuller). Jordan Fuller serves as COO and Dr. Jordan B. Peterson, PhD as scientific advisor.