From the Desk of Joleen Wilson, Pathway Dietician: Metabolism is King, Part 3
Written by: Joleen Wilson, Registered Dietician, Certified Nutrition Support Clinician, for Pathway for Eating Disorders Treatment at Brookhaven Hospital
In this third installment about metabolism, let’s look at the neurochemicals that help us feel full or cause us to feel hungry. Hunger and satiety (fullness) are chemically regulated by the body by the release of three chemicals: Neuropeptide Y, leptin, and ghrelin.
Neuropeptide Y is produced in response to restriction of intake. It functions to increase hunger and store anything that comes in, because metabolism is decreased over time. This is the main reason why it is so common to gain back weight after strict dieting.
Leptin is the hormone that promotes satiety. It inhibits the production of Neuropeptide Y. Leptin is produced by adipose tissue (fat tissue); therefore, if a person has excessive adipose tissue, they will produce more leptin. Having too much leptin circulating causes the body to become resistant to it, much as a person with diabetes may be resistant to insulin. In other words, the person with extreme morbid obesity may have a lessened response to the signal that is supposed to turn off hunger signals. A person with minimal fat stores will produce less leptin, which may contribute to rebound binge eating as a response to restricting. This is one of the many reasons why extreme low calorie diets do not work in the long term. Once we feel extremely hungry, all notions of moderate, conscious eating become irrelevant, often resulting in “The Last Supper” overeating and “falling off the wagon”.
Ghrelin is another chemical that regulates food intake. It is produced mostly in the stomach and is also a stimulator of hunger. Ghrelin is produced when the stomach is empty; as the stomach becomes full, the stretching of the gastric wall causes ghrelin production to reduce. A lack of sleep will results in increased production of ghrelin–so get your Zz’s!
Some strategies to control the chemical response:
- Eat enough calories to avoid massive output of Neuropeptide Y. When the body has what it needs to survive, it does not go into panic mode.
- Eat your complex carbohydrates (whole grains, starches, and vegetables). A balanced diet that includes carbohydrates helps with leptin production. So those low carb diets that tout weight loss actually increase hunger, making it harder to diet!
- Eat consistently throughout the day. Having regular meals controls the release of ghrelin. Consuming fiber, fat, and protein will slow digestion, fill the stomach, and help “shut off” ghrelin production.