In which process does insulin primarily promote fat storage?

Insulin primarily promotes fat storage through the process of lipogenesis. Lipogenesis is the synthesis of fatty acids and triglycerides from glucose and other substrates, leading to the formation of fat in adipose tissues. When insulin is released in response to elevated blood glucose levels, it encourages the uptake of glucose into adipocytes (fat cells), where the glucose is converted into fatty acids. These fatty acids are then used to form triglycerides, which are stored as fat.

Insulin also inhibits lipolysis, which is the breakdown of stored triglycerides into free fatty acids and glycerol, thereby promoting fat storage by suppressing the mobilization of fats. Overall, insulin plays a vital role in the regulation of fat metabolism, and its primary function is to store energy, particularly in the form of fat through lipogenesis.