The Atkins diet, based on low-carbohydrate and high-protein foods for the loss of weight, may not be universally recommended. Dr. Klaus-Dieter Lessnau, a clinical assistant professor of medicine at New York University School of Medicine, describes a complication which might have ended in death for a 40-year-old obese woman on the Atkins diet. She followed the Atkins diet and also took the supplements. After having breathing difficulties, she went to the hospital and was diagnosed with ketoacidosis. This affection appears when dangerously high levels of acids called ketones build up in the blood. Ketones are produced in the liver when insulin levels fall due to starvation or diabetes. The researcher stated that a low-carbohydrate diet, as Atkins, can lead to the production of ketone. "The Atkins diet is not a safe diet in everybody. It can cause potentially life-threatening problems," Lessnau said. Still, some experts from the outside say the woman's case is a rare one and does not represent a major health threat. "I think this is an isolated case. The idea that serious ketoacidosis could be triggered by a low-carb diet does not happen very often," said Dr. Paul Clayton, from the London School of Medicine. The problem may have not been caused by the diet. Gary D. Foster, director of the Center for Obesity Research and Education, stated about the case "This shows that people who are obese and lose a lot of weight quickly should be doing so under medical supervision. Losing weight quickly brings its own set of problems […] We have known for a long time that losing weight quickly is a bad idea medically."