Which of the following hormones decreases appetite?

Leptin and insulin are both hormones that play crucial roles in regulating appetite and energy balance.

Leptin is produced by adipose (fat) tissue and signals to the brain that there are sufficient energy stores available. When leptin levels are high, which typically occurs in individuals with higher body fat, it signals the brain to reduce appetite and increase energy expenditure. This hormone helps to prevent overeating by marking the body's energy balance.

Insulin, produced by the pancreas in response to food intake, helps regulate glucose levels in the blood. Beyond its role in glucose metabolism, insulin also has effects on appetite. Elevated insulin levels after a meal can lead to a reduction in appetite, signaling to the body that food intake should be decreased as there is sufficient energy available.

The combination of these two hormones working together effectively communicates the state of energy stores and nutrient availability to the brain, leading to decreased appetite and supporting homeostasis. Therefore, the selected answer accurately reflects the role of both leptin and insulin in appetite regulation.