Final answer:
Leptin is the hunger-suppressing hormone that is circulated in the blood and detected and monitored by the brain. It is produced by adipose tissues and plays a role in regulating the balance between food intake and energy expenditure.
Step-by-step explanation:
The hunger-suppressing hormone that is circulated in the blood and detected and monitored by the brain is Leptin. Leptin is a hormone produced by adipose tissues (fatty tissues) and plays a role in regulating the balance between food intake and energy expenditure. When there is more adipose tissue, more leptin is released, which decreases hunger by giving a feeling of fullness. Obesity may be related to the malfunctioning of leptin.