What I am learning in my Exercise Science Degree.
As you may or may not know, hormones play more of a control in a lot of different areas in the body including calorie intake. Today I will be explaining how hormones play a role in calorie intake and why certain issues can cause problems with it.
Above image is shows the 3 primary hormones that are involved in the regulation of food intake. There are others that will also be included below.
So the hypothalamus is the appetite control center of the brain. It is found in the center of the brain and is part of the endocrine system, which includes the pancreas. Two areas help with the control of calorie intake: ventromedial nucleus, which is part of the hypothalamus which is a nucleus (center) involved in terminating hunger, fear, thermoregulation, and sexual activity, which is where you are told when you are full (satiety) and lateral hypothalamus which is the hunger center which tells when we are hungry, is another type of nucleus in the hypothalamus which also helps regulate the metabolism besides regulating food intake.
The hypothalamus is not the only area that works with the hormones that affect food intake. The GI tract releases hormones that affect hunger signals. Peptides are also considered hormones as you will see. There are four hormones that affect hunger signals: cholecystokinin (CCK) is stimulated when stomach is full and it decreases the appetite; Glucagon-like peptide 1 (GLP-1) is released in the small intestine, which also decreases the appetite; Peptide YY (PYY) is also released in the small intestine and also decreases the appetite; and ghrelin which increases the appetite is released in stomach.
Now the adipose tissue (fat tissue) in your body holds a hormone called leptin. When it is released from the fat storage, it release hunger. Now you would think that having excess fat can be a good thing, which as we all know it is not. Leptin and ghrelin actin in opposing ways, but unfortunately those considered in the obese category have higher leptin levels but are resistant to effects.
Now you will notice insulin is mentioned. Insulin is a hormone. Yes insulin increases when ghrelin is released. Insulin is produced in the pancreas, but that what helps with the transportation of glucose throughout the body which is put in the glycogen in the muscle and liver.
Now exercise affects hunger and fullness hormones. Acute, vigorous exercise in PYY and GLP-1 which both reduce hunger. Now. you are probably thinking why am I famished after a workout. That’s because ghrelin, which is the hormone that cause you to be hungry until you are in an energy deficit. Basically when your body uses all the energy that it has stored, like glycogen stores in the muscle. Remember glycogen is created from the carbohydrates that are ingested by your body. This is why you are hungry after an intense workout as you have completely depleted your energy stores.