Why an all-animal diet drives insulin and inflammation down
A carnivore pattern eliminates essentially all carbohydrate, so postprandial glucose and insulin excursions become minimal and the body relies on fat and protein for fuel, often entering nutritional ketosis. Removing all plant foods also removes most dietary fiber and the FODMAPs, lectins, and other compounds that some people react to, which is the proposed reason a subset report reduced bloating or autoimmune-type symptoms.
Those symptom reports are largely anecdotal and short-term; the diet has not been studied in long-term controlled trials, so claims that it treats specific diseases are not supported by strong evidence.
The fiber, polyphenol, and microbiome trade-off
The cost of eliminating plants is the loss of fiber, polyphenols, vitamin C from non-organ sources, and the substrate that maintains a diverse gut microbiome. Fiber removal reduces short-chain fatty acid production in the colon, and long-term effects of this on gut and metabolic health are not well characterized. LDL cholesterol can rise substantially on high-saturated-fat versions.
This is general educational information, not medical advice. A diet this restrictive carries real nutritional and cardiovascular risks for some individuals and should not be undertaken, especially with an existing condition, without guidance from a qualified clinician.