Ketoacidosis due to a low-carbohydrate diet in an elderly woman with dementia and abnormal eating behavior

Strict restriction of carbohydrates can induce symptomatic ketoacidosis. We herein report a 76-year-old demented woman who developed ketoacidosis after 1 month of abnormal eating behavior involving selectively eating hamburger steak (estimated carbohydrate =12.7 g/day). Laboratory tests showed high-anion-gap metabolic acidosis with elevated blood ketone levels. She was successfully treated with intravenous fluids followed by oral intake of a regular diet. She remained relapse-free after correcting her eating habits. Healthcare providers should know that abnormal eating behavior in demented people can lead to an extremely-low-carbohydrate diet and cause atypical ketoacidosis unexplained by diabetes, heavy alcohol intake, or starvation conditions.