Final answer:
Mr. Garrett's constant feeling of hunger could be attributed to hypoglycemia, a condition with low blood sugar levels that can improperly signal the brain to continue feeling hungry.
Step-by-step explanation:
Mr. Garrett often overeats, complaining that he feels hungry all the time. His doctor has suggested that his problem is likely due to a malfunction related to the sensation associated with blood sugar levels known as hypoglycemia. Hypoglycemia is a condition characterized by abnormally low blood sugar levels, which can trigger hunger signals even when the body doesn't need more food. Prolonged low blood sugar levels can stimulate hunger hormones and neurotransmitters to signal the brain that the stomach is not full and thereby fail to reduce hunger. This is different from hyperglycemia, which signifies a high blood sugar level that occurs when the body has insufficient insulin or is not utilizing insulin properly, leading to high levels of glucose in the blood.