A Florida man in his 40s tried a strict carnivore plan for eight months. He says he felt leaner, more energetic, and mentally sharp. However, unusual yellow patches soon appeared on his palms, elbows, and the soles of his feet.

Doctors at a Tampa hospital traced the issue to his diet. He reported eating sticks of butter, fatty hamburgers, and an extreme amount of cheese—six to nine pounds a day. Moreover, he had ignored the spots for about three weeks before seeking help.

Examination found multiple painless, yellow nodules. His blood work was striking. Total cholesterol measured above 1,000 mg/dL; his previous levels had ranged from 210 to 300. Clinicians diagnosed xanthomas—fatty deposits under the skin that can signal serious cholesterol problems. The case, published in JAMA Cardiology, emphasized the urgency of treating severe hypercholesterolemia to prevent complications. The report did not disclose the man’s long-term outcome.

Nutrition experts caution that all-meat regimens can create other risks. For example, very low fiber harms gut health. Vitamin and mineral gaps can also develop; even iron from meat absorbs poorly without vitamin C. Yes, rapid weight loss can occur on any calorie-deficit plan. But, they argue, a balanced approach typically achieves similar results with fewer hazards.

The broader lesson is simple. If a new eating plan triggers strange symptoms—especially skin changes—contact a clinician promptly. And before making drastic dietary shifts, discuss safer, sustainable options with a healthcare professional.