There's a scientific reason behind your longing for the last slice of pizza despite being sickeningly full.
Although it's often brushed aside as a lack of self control, compulsive eating is a real thing and a new study may have discovered what causes it.
Researchers at the University of Cambridge examined how the brains of 150 meth addicts, alcoholics, and compulsive eaters dealt with everyday choices compared to subjects without addiction problems.
The study aimed to test previous theories that we make decisions using one of two distinct processes - either based on our future goals or out of habit.
Subjects completed a computer training program that measured their ability to overcome habitual impulses and act in a way that would positively impact on their future goals.
Perhaps unsurprisingly they found those who suffered from compulsive disorders tended to rely on their habitual instinct rather than goal-oriented ones.
Furthermore - and here comes the sciencey bit - scans of subjects' brains revealed those with compulsive disorders had fewer neurons in the orbital frontal cortex and left ventral striatum. That's the bits that handle our perception of goals and rewards to you and me.
The study is the latest in a growing body of research suggesting compulsive behaviour - whether it be drinking, exercising or eating - is caused by factors outside of our control.
Source: Refinery 29