Which description best captures insulin's effect after a meal?

• A. It promotes lipolysis
• B. It inhibits glycogenesis
• C. It decreases transport of glucose into cells
• D. It promotes glucose uptake and glycogenesis while inhibiting lipolysis

Answer: (D)

After a meal, insulin rises to store the incoming energy. It drives glucose into cells, especially muscle and adipose tissue, by promoting GLUT4 transporters to the cell membrane, which lowers blood glucose. It also activates glycogen synthase to convert glucose into glycogen, increasing glycogenesis in liver and muscle. At the same time, insulin suppresses lipolysis in fat tissue, reducing the breakdown of fats. This combination—glucose uptake and glycogen formation with inhibited fat breakdown—best fits the post-meal insulin effect.