Diabetic Ketoacidosis is well documented in diabetic people[1], alcoholics, and in conditions of starvation[2] and the mechanism is the same. Ketone tests were developed for this purpose. Note starvation there, where the body starts using its own fats for energy. Here's a case report of it happening to someone on a ketogenic diet[3].
[1] https://www.cdc.gov/diabetes/basics/diabetic-ketoacidosis.ht...
[2] https://www.ncbi.nlm.nih.gov/books/NBK534848/
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7220017/