Tuesday, January 6, 2009

Why Do We Get Hungry?

By Susan Blair

The amount you eat is not for the lack of willpower. Rather, it is an inborn drive that helps to assure the survival of the human race. If you try to override this biological urge by dieting or restricting your food intake your body counteracts by releasing powerful chemicals that stimulate your hunger and makes you want to eat. Each time you purposely eat less your body starts a complex process in your body that compels you to eat.

That growling in your stomach really is being controlled by a complex chemical process that originates in your brain and is triggered by either sensory or mechanical origins. Once your brain thinks your body needs food it sends a wave of chemical signals that make you feel hungry.

After extensive research scientists have discovered that it is the hypothalamus part of our brain that is responsible for regulating our hunger. The hypothalamus cells send signals to other cells in our brain that begins the signals that tells you how much and what to eat. These chemical signals travel both ways so we know when to stop eating.

What starts the chemical chain? Food can be the trigger that stimulates the brain to turn the desire to eat into the actual act of eating. How a food smells, what it looks like, how you remember it tasting - in short, its sensory appeal - excites chemicals within the brain.

Another way the process starts is at a cellular level, when messages sent to the brain tell it that fuel is needed and that it's time to eat.

Chemicals in the brain called neurotransmitters transmit signals to other brain neurons when your body feels it needs nourishment to keep running. Although new discoveries are being made all the time about how the hunger process works scientists feel that one special neurotransmitters called Neuropeptides is what triggers the need for carbohydrates

According to the theory, low levels of glycogen (carbohydrate in storage form in your body) and low blood sugar levels stimulate NPY's release from the hypothalamus. As NPY levels increase, so does your desire for sweet and starchy foods.

When you sleep your blood sugar and glycogen levels get low and they send a signal to your brain to release more Neuropeptides. That is why some of our favorite breakfast foods like fruit, breads and cereals are rich in carbs.

If you skip breakfast your Neuropeptides increase so that as the day progresses you are ready for a carb binge and you overeat. This craving is not something that we can control with willpower, rather it is an innate biological urge that we must follow. Other factors such as dieting and stress are thought to trigger the production of Neuropeptides too. - 15995

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