What is Peptide YY?

How is your body able to recognize when you have eaten enough food? After eating, the hormone peptide YY (PYY) will be produced by the small intestine and released into your bloodstream. PYY communicates to your brain that you are full and decreases your appetite. The amount of PPY released depends on the type and quantity of food eaten.

How Does Your Body Use PYY? 

After it is released in your bloodstream, PYY binds to receptors, or cells that receive signals, in the brain. It also functions by slowing down the movement of food in the digestive tract.

Your body produces PYY when there is food in the digestive tract, especially food that contains fat and protein. Eating high calorie foods causes your body to produce more PYY than eating low calorie foods. PYY levels are the highest two hours after eating but eventually PPY decreases. Most people have low levels of PYY after not eating for a long period of time.

What Problems Can Occur with PYY? 

Although it is uncommon, very high levels of PYY will decrease your appetite. High PYY levels are often associated with conditions that may lead to weight loss such as eating disorders, inflammatory bowel disease and certain cancers. Low PYY levels mean that you may experience an increase in appetite. Lower PYY levels may contribute to weight gain, however it is not believed to be the main cause of obesity. It is very rare to have a genetic or endocrine disorder of PYY.

Questions to Ask Your Healthcare Team

  • What are some examples of high and low-calorie foods?
  • How can I monitor the foods that I eat?
  • Should I see a nutritionist to develop a eating plan?

Edited: January, 2019
Editor: Irina Bancos, MD