Long-term adherence to a keto diet regimen -- high in meats, proteins and oils -- may pose health risks, according to a study in mice. And while it may seem OK on the surface, new research in mice suggests that staying on a keto regimen for a long time might be risky. Body weight was lowest in animals in low-fat eating regimen, but those on a keto diet weighed less than those on a Western-influenced regimen. The findings dovetail with the experience of a neurologist at Johns Hopkins in Baltimore who offers a keto diet as a treatment option for patients with epilepsy. More informationHarvard Health has more about how a keto diet works.