Thursday, January 29, 2015
With the start of a new year, the topic of conversation at parties, luncheons, and other social events often centers on food, diets, and weight control. How many people will make a New Year's resolution to lose weight? Armed with the knowledge that you should simply eat less and move more, weight control should not be a challenge, right? Why is it so difficult to stick to a diet plan? There is one culprit that stands above the rest... APPETITE.
It's difficult to control weight without being able to regulate your hunger and craving for food. Today, we know that appetite is a complex process that involves the senses as well as many signals being sent to the brain by hormones, nerves, and proteins in the gut. Unfortunately, we often listen to hunger cues that prompt us to eat, but are less sensitive to satiety signals that tell us to stop eating.
Appetite is controlled by numerous substances along the gastrointestinal tract that send messages to the brain. For example, the stomach sends hunger signals to the brain through contractions, nerves, and a messenger called ghrelin. After eating, the stomach stretches and sends satiety or fullness signals to the brain. Several other substances in the intestines, with names such as PYY, GLP-1, and cholecystokinin, signal the body to stop eating. Blood sugar also affects appetite. After fasting for a few hours and after eating refined carbohydrates, blood sugar is lowered and the desire to eat increases.
External cues, such as the sight and smell of food, also can trigger a series of reactions that activate appetite. Even the temperature of the room affects appetite; colder rooms are associated with increased eating.
Although researchers are discovering more about appetite and its complex mechanisms, we still don't have all the pieces to the puzzle. Someday, you may be able to control your appetite with a supplement containing a specific hormone or peptide. In the meantime, try these practical ways to control appetite:
For more discussion of appetite and its link to weight control, read "The Science of Appetite" by Jeffrey Kluger in Time, June 11, 2007.
This article originally appeared in Nutri-bytes (December 2007), a service of the University of Cincinnati College of Nursing and was adapted for use on NetWellness with permission.
Last Reviewed: Jan 06, 2010
Bonnie J Brehm, PhD, RD
Professor of Nursing
College of Nursing
University of Cincinnati