3. HUNGER AND APPETITE. Understand the mechanisms that drive us to eat. What regulates hunger and appetite? Which natural biochemicals in our bodies can dampen hunger, and how can we activate them?

100+ BEST WEIGHT LOSS TRICKS OF ALL TIME

Appetite.

Appetite is the desire to consume food. It may or may not be driven by hunger.

Eating triggers.

Certain things trigger physiological signals that tell your body to get ready for eating. These triggers may be psychological, chemical, cultural, the result of habit etc. Factors such as the smell or sight of food, sounds associated with food such as clinking tableware, and even mental images and thoughts of food stimulate your cerebral cortex. Your brain then sends messages via the vagus nerve to your stomach, telling it to secrete gastric juices in readiness for receiving food.

People usually call the sensation of desiring or needing food “hunger”, but that feeling may not be true hunger at all. The desire for food—which is called “appetite”—can be triggered by many things other than true hunger. Often, the terms “hunger” and “appetite” are used interchangeably, but their meanings are, in fact, different.

Regulation of hunger and appetite.

Your body regulates appetite via the neuroendocrine system.

Together the endocrine system and nervous system can be called the “neuroendocrine system”. It’s the endocrine system that detects changes in your body, such as those that happen when food enters your mouth. It reacts to these changes by releasing hormonal messengers.

These appetite-regulating hormones include leptin, ghrelin, insulin and cholecystokinin (CCK). They play a role in hunger, satiation/ satiety and energy balance. Meanwhile your nervous system sends out electrical impulses and biochemicals called neurotransmitters. These direct the various parts of your digestive system to churn and process the food, and keep pushing it through your body. In other words when you eat food, your body responds in numerous ways. Signals are transmitted back and forth between your brain and your body’s other organs.

The stretching of the stomach signals fullness.

Your brain and stomach start to register feelings of fullness about 20 minutes after you begin eating a meal.

When you eat, food passes into the bag-like stomach, which stretches to accommodate the food. The stretching of your stomach triggers the appetite control switch in your brain. This tells you to stop eating (satiation) and dampens your hunger for a while, until your body requires more energy and nutrients.

TIP: To make good use of this appetite-reducing trigger, eat foods that occupy a lot of room in your stomach, but contain few Calories. Examples include vegetable soups, which contain quite a lot of water, and fresh garden salads.

When your stomach is chronically over-stretched by overeating, your body’s sensors lose their sensitivity. That appetite control switch in your brain becomes confused and the “stop eating” signals don’t work properly.

TIP: The solution to this problem—eat smaller portions.

CCK helps reduce appetite.

When food enters your stomach it also triggers off the release of cholecystokinin, or CCK. This is a protein that helps reduce appetite and prolong satiety. One of CCK’s actions is to close the valve that leads from your stomach into the lower GI tract, temporarily trapping the food so that the stomach can do its work of grinding and breaking down the food into smaller particles. The longer food remains in your stomach, the longer you feel full and satisfied.