Etiology: prolonged fasting, eating disorders, severely calorie-restricted diets, restricted access to food
Low insulin/high glucagon in fasting state leads to increased lipolysis. Fatty acids initially converted to acety-CoA, which is then oxidized by the Kreb cycle.
When Kreb's cycle oversaturated by excessive adipose breakdown, acetyl-CoA enters ketogenic pathway, resulting in ketone body production
Mild ketosis (1mmol/L) occurs  after fasting for ~12 to 14 hours.
Ketoacidosis rises with continued fasting, peaks after 20 to 30 days (8-10mmol/L).
Starvation ketoacidosis
Diabetic ketoacidosis
Alcoholic ketoacidosis
Diabetic ketoacidosis 
Lactic acidosis
Toxic alcohols 
Cerebral edema in DKA
Uremia