Appetite and willpower

Although we know that many factors influence the way we eat, it is still not well understood what controls normal eating behaviour.

Is our environment making us overweight?
Partly. Can we blame it on technology? Perhaps. The phone, the remote control, riding the elevator or the escalator instead of taking the stairs, driving the car instead of walking - all promote less energy use.

Although what we eat and how much we eat is influenced by a number of factors such as sight, taste, and smell, it is also influenced by genetic, psychological, and social factors. Scientists have discovered that appetite and metabolism are controlled by a complex system of hormones and nerve cells in an intricate communication between the body and the brain.

Leptin tells your brain that you're full.
Recently, the discovery of the hormone leptin, which is involved in regulating the energy balances in the body, helped shed some light on this situation. Leptin is your body's thermostat to help with long-term weight maintenance. When your body has consumed enough food, leptin sends your brain a message that you are full and don't need more food, decreasing your appetite.

So what makes you hungry even if you've just eaten? Scientists believe it is caused by a communication breakdown. The brain ignores the signals that it gets from leptin and other hormones involved in appetite control.

And then there is a "set point" weight.
It is also believed that leptin is involved in regulating a "setpoint" for your body weight, which is automatically set by your brain and body. Your body is set up through evolution to vigorously defend your setpoint weight. That's why, even though you eat less, you may burn less fat and stop losing weight. But you can reset your setpoint in order to continue losing weight. You just need to increase your heart rate through moderate exercise, such as brisk walk for half an hour a day.

Source: www.medbroadcast.ca