EATING FOR PLEASURE
'the homeostatic system'
Seeing, smelling and even hearing the word 'cake' activates chemicals in the brain involved in shame, depression, and repression, triggering the release of epinepherine, the brain's "food" chemical.
Brain scans show that obese people have reactions to food similar to reactions experienced by sexual deviants.
EATING FOR SURVIVAL
'the hedonic system'
When food reaches the stomach, electrical signals from the brain speed up digestion and trigger the brain to eat more. Seeing cake becomes more appealing.
The hormone dopamine tells the brain to stop eating, but in obese people, the brain is unable to accept the chemical receptor.