What is the primary effect of growth hormone on metabolism?

Growth hormone plays a crucial role in metabolism by promoting protein synthesis and increasing lipolysis. This anabolic effect encourages muscle growth and repair by facilitating the uptake of amino acids, which in turn enhances protein synthesis in various tissues, particularly muscle. Additionally, growth hormone stimulates lipolysis, the breakdown of fat stores, leading to an increase in free fatty acids in the bloodstream, which can be utilized for energy. This dual action supports overall body composition by promoting lean body mass while simultaneously reducing adipose tissue.

The primary effects of growth hormone are particularly important in situations such as exercise and fasting, where the body necessitates efficient energy utilization and muscle preservation. Therefore, the metabolic effects induced by growth hormone align with its physiological role in growth and energy mobilization, making the correct option a reflection of this multifaceted influence on metabolism.