Is a ketogenic diet worth trying, or do its risks outweigh its benefits?

Georgia A. EdeMD · psychiatrist, nutritional and metabolic psychiatry

For a serious mood or psychotic illness that intensive standard treatment has not controlled, medically supervised carbohydrate restriction is worth considering as an addition to treatment. It is not established, and she says so in the same papers.

What it rests onA retrospective analysis of 31 hospitalised adults with major depressive disorder, bipolar disorder or schizoaffective disorder, which she wrote: all 28 who stayed on the diet beyond two weeks improved, 43 percent reached clinical remission, 64 percent were discharged on less medication. Its own limitations section states that the extent to which the diet contributed cannot be ascertained, that nobody was blinded, and that several dietary variables changed at once. She is separately a co-author of a 2026 review titled 'The ketogenic diet is not for everyone', and first author of a 2026 consensus listing absolute contraindications. Her declared interests on the 2022 paper are stock options in DietDoctor.com; by 2026 she declares a USD 750 CME course, book royalties, eight advisory boards and conference honoraria.

Neal BarnardMD, FACC · founding president, Physicians Committee for Responsible Medicine

For most people, the risks of a very-low-carbohydrate diet outweigh the benefits, and it should not be a long-term strategy.

What it rests onA narrative review in Frontiers in Nutrition on which he is senior author of seven (Crosby L, Davis B, Joshi S, Jardine M, Paul J, Neola M, Barnard ND; Front Nutr 8:702802, 28 Jul 2021). Its conclusion states that LDL cholesterol can rise, sometimes dramatically, that pregnant women on such diets are more likely to have a child with a neural tube defect even when supplementing folic acid, that the foods increasing on these diets are linked to higher risk of chronic kidney disease, cardiovascular disease, cancer, diabetes and Alzheimer's disease, and that for most individuals the risks of such diets outweigh the benefits. He serves without compensation as president of the Physicians Committee for Responsible Medicine and receives book royalties and lecture honoraria.

Christopher M. PalmerMD · psychiatrist, McLean Hospital and Harvard Medical School

For a serious mental illness that has not responded to standard treatment, a medically supervised ketogenic diet is worth asking a clinician about. It is a medical intervention, not a diet, and he says himself it is not established.

What it rests onTwo uncontrolled case reports of remission in chronic schizophrenia, set against a three-year study of over 6,000 medicated adults with schizophrenia in which 4 percent reached full relief. His own peer-reviewed writing says randomised controlled trials are still needed to demonstrate efficacy and safety, and his own 2026 case series documents hypomania or mania in nine people starting the diet. He declares royalties on Brain Energy and ownership of MH2, a practice that provides the therapy.