Regulation of Hunger

Hormones that regulate hunger

Ghrelin

Insulin

PYY

Leptin

Ghrelin

Released from stomach, signals feelings of hunger

Insulin

Rise in blood sugar levels after a meal triggers pancreas

Pancreas secretes insulin

Suppresses appetite by acting on brain

PYY

Secreted from small intestine

Suppresses appetite

Counters ghrelin

Leptin

Produced by adipose (fat) tissue

Suppresses appetite as level increases

When fat decreases leptin levels fall, apetite increases

Leptin resistance

Weight gain leads to more fat mass and higher leptin levels

Increase fat stored and whole-body inflammation leads to this

Signal of leptin to the brain is disrupted

Low sense of leptin leads to overeating and cravings

Increased calorie intake leads to continued weight gain

Cycle repeats