When we are motivated to take action, certain regions of our brain are activated. But what actually trigger the increased blood flow carrying more fuel and oxygen to these areas of the brain in order to activate the brain?

For example what triggers the trip to the fridge? Is it perhaps a sense of neuro-hunger? Is there a special substance involved?

Neuroscience is not clear about this yet. There are too many reasons, but brain chemicals may be a powerful one.

In a study, researchers found that mice injected with opioids, chemicals that caused pleasurable feelings, ate up to six times the normal amount of pure fat. But mice given an injection to shut down a brain region called the amygdala, which is important for emotions and memory, ignored the temptation of the same scrumptious lard.

Researchers suggest that understanding how brain chemicals and regions work has implications for diet and weight control.