Growth hormone affects which metabolic pathways?

• A. Lipid metabolism
• B. Carbohydrate metabolism
• C. Protein metabolism
• D. Lipid, carbohydrate, and protein metabolism

Answer: (D)

Growth hormone has broad effects that touch the body’s main fuel pathways: fats, sugars, and proteins. It promotes lipolysis in adipose tissue, activating hormone-sensitive lipase to break down triglycerides into free fatty acids and glycerol, which can be used for energy and help reduce fat mass. On carbohydrates, GH can antagonize insulin’s actions by reducing glucose uptake in muscle and fat and by increasing hepatic glucose production through gluconeogenesis and glycogenolysis, which can raise blood glucose levels and contribute to insulin resistance when GH is in excess. For proteins, GH is anabolic: it stimulates amino acid uptake and protein synthesis in tissues like muscle and liver, supporting growth and lean body mass while reducing protein breakdown. Because growth hormone influences all three major metabolic pathways, it affects lipid, carbohydrate, and protein metabolism.