Which hormone is proportional to fat mass and anorexigenic?

Which hormone is proportional to fat mass and anorexigenic?

• A. Ghrelin
• B. GLP-1
• C. CCK
• D. Leptin

Answer: (D)

Leptin serves as the primary adiposity signal. It is produced by fat cells in proportion to how much fat is stored, so higher fat mass means more leptin circulating. In the brain, leptin acts to reduce appetite and increase energy expenditure by influencing hypothalamic circuits (promoting pathways that suppress hunger and inhibiting those that stimulate it). This makes it the hormone that is both proportional to fat mass and anorexigenic. Ghrelin, in contrast, rises with fasting and stimulates appetite. GLP-1 and CCK promote satiety after meals but are not directly tied to total fat mass as signals; they respond to food intake rather than adipose stores.

Leptin serves as the primary adiposity signal. It is produced by fat cells in proportion to how much fat is stored, so higher fat mass means more leptin circulating. In the brain, leptin acts to reduce appetite and increase energy expenditure by influencing hypothalamic circuits (promoting pathways that suppress hunger and inhibiting those that stimulate it). This makes it the hormone that is both proportional to fat mass and anorexigenic.

Ghrelin, in contrast, rises with fasting and stimulates appetite. GLP-1 and CCK promote satiety after meals but are not directly tied to total fat mass as signals; they respond to food intake rather than adipose stores.