Now is the time of year when family and friends gather together and share large meals. We eat … and keep eating … and keep eating. Our body has a number of signals that tell us to stop eating, but the mashed potatoes and stuffing tempt us to ignore them. What are those signals?
The hypothalamus sits in the center of our brains; among the many things it regulates is our hunger. The hypothalamus produces proteins that can increase or decrease hunger. The system works like a seesaw: Both types of proteins are always present, but which effect is stronger depends on which is produced more. This type of regulation is known as “antagonistic control,” and it’s an important way for the body to maintain homeostasis, the body’s internal balance.
The hypothalamus’s seesaw hunger control is in turn influenced by hormones. Hormones circulate around your body and come from parts of the body related to our energy intake and storage, including the gut, fat and pancreas. Changes in the body, such as by weight loss or physical activity, can affect how much of each hormone is released.
You’ll notice when you’re eating that it takes a little while to feel full. This 20- to 30-minute delay between when we start eating and when our body tells our brain to stop eating is due in part to the time it takes hormones that stimulate hunger, such as ghrelin, to reach a low and hormones that stimulate satiety (fullness), such as cholecystokinin, to reach a peak.
So, when you sit down for that holiday meal and you don’t want to overeat, take a few minutes to think about the signals in your body controlling your hunger before reaching for that last turkey leg!
Anne R. Crecelius, PhD, is an assistant professor in the department of health and sport science at the University of Dayton in Dayton, OH.