Why Do We Eat? A Neurobiological Perspective. Part I

[Northerner]

As with all voluntary movements, eating food is an expression of activity in the brain. The brain integrates various inputs from around the body, and outside the body, and decides whether or not to execute the goal-directed behaviors of food seeking and consumption. Research has uncovered a lot about how this process works, and in this series I'll give a simplified overview of what scientists have learned about how, and why, the brain decides to eat.

The Gatekeeper of Voluntary Behaviors

Let's start at the broadest level. The brain has the capacity to drive feeding behavior at any time of day. Why do we only seek food and eat it at some times and not others? Why do we perform any behavior at specific times and not others? The brain contains a sort of 'gatekeeper' function that selects among all possible behaviors at any given moment, executing those that are currently the most relevant.

This gatekeeper function is part of the reward system*, centered in the midbrain. The reward system is responsible for selecting/motivating all voluntary behaviors, including the seeking and consumption of food. Stimulating this system in the right way can strongly influence feeding behaviors

http://wholehealthsource.blogspot.co.uk/2012/10/why-do-we-eat-neurobiological.html