I have a question about ketones. Many popular diets, such as Atkins, claim they work by breaking down fat, which leads to production of ketones. Yet in a Type 1 diabetic, ketones are very dangerous. Why are non-diabetics able to produce ketones on these diets without significant apparent danger of DKA, while Type 1 diabetics are not?

Ketones are indeed a product of fat breakdown in the body and when one is breaking down fat during weight loss that is not due to absence of insulin the body can process them without doing great harm to the body. They are expelled in the urine. That may be why the diets call for plenty of fluids to help rid the body of ketones. When one has no insulin or is deficient in insulin and is not able to process carbohydrate or protein for energy, the ketones become much more concentrated and the body actually changes its pH [acid level] — thus the term diabetic ketoacidosis. This is not a good condition: it can be life threatening in a person with diabetes. In a person with insulin production, it may cause odorous breath, headache, and depending on other circumstances, can lead to severe illness.

JM