"While a ketogenic diet has been shown to decrease appetite while burning fat and maintaining muscle, it is not without risk," said Holly Pudwill, president and clinical dietitian at Balanced Nutrition of Jacksonville. "Ketones are a byproduct of ketosis. If those build up, a condition called ketoacidosis can result." When this happens, ketones build up in the blood, making it too acidic and causing dehydration. In very extreme cases, this dehydration can lead to coma or death.