Final answer:
Ketoacidosis occurs most frequently in people with poorly controlled diabetes mellitus, where the breakdown of fatty acids leads to increased acidity in the blood. In the case of the adolescent in the question, diabetic ketoacidosis is most likely caused by the inability to regulate blood sugar levels due to diabetes.
Step-by-step explanation:
Ketoacidosis occurs most frequently in people with poorly controlled diabetes mellitus. When certain tissues in the body cannot get adequate amounts of glucose, they depend on the breakdown of fatty acids for energy. This results in the production of ketone bodies, which increase the acidity of the blood. In the case of the adolescent in the question, diabetic ketoacidosis is most likely caused by the inability to regulate blood sugar levels due to diabetes.