Do you ever find yourself eating when you are not hungry? If you think about the cause of eating too much, or overeating, you might even label it as a bad habit. While that may not sound scientific, new research is showing that overeating may just indeed be a bad habit.
Recently, researchers set out to determine how habits affect our eating behavior. Their focus was mainly on the neurological system that controls habits, specifically in the ventromedial prefrontal cortex, an area of the brain that anticipates the value or reward of an expected event. The ventromedial prefrontal cortex is important to the brain’s reward pathway, managing positive and negative reinforcement of behavior.
How the Reward Pathway Works
The reward system of the ventromedial prefrontal cortex (located in the mid-lower section of the frontal lobe) works something like this: when you are hungry and are sitting at a table and a plate of food arrives, the neurons in this area of the brain light up in anticipation of the meal. The neurons in the ventromedial prefrontal cortex are firing because it is detecting a high reward.
When we are full, the firing of neurons in this area of the brain is greatly diminished. If someone were to bring you another plate of food, the ventromedial prefrontal cortex would barely fire at all. This low firing of neurons is designed to devalue the experience of eating, discouraging us from continuing to eat.
Finding the Possible Cause of Overeating
In order to study the effects of the habit system on overeating, the researchers chose 32 healthy volunteers to sit in front of a computer screen and press a button whenever an image appeared signaling them to do so. When the button was pressed, a machine next to the volunteer would release either a M&M or a Frito chip. The volunteer ate whichever snack the machine ejected.
The volunteers were divided into two groups. One half of the them did the computer exercise for only two sessions of eight minutes each. The other half completed 12 sessions of eight minutes each. Having six times the practice of the first group, the second group was eventually more likely to press the button out of habit. The second group was the “habit” group and the first group was the “non-habit” group.
In order to compare the responses of the ventromedial prefrontal cortex in the non-habit group versus the habit group, the researchers used a fMRI device to measure real-time neuron activity. Not surprising to them, what the scientists found was very different brain activity between the two groups of volunteers.
The researchers first tested the non-habit group. They found that the ventromedial prefrontal cortex was activated prior to each press of the button in anticipation of the snack, encouraging the volunteers to eat. However, that was while they were still hungry. Next, the non-habit group volunteers ate a large meal. Now no longer hungry, these volunteers pressed the button on the machine and the fMRI showed diminished activation in that area of the brain. The anticipated reward was minimal since the hunger was gone. The ventromedial prefrontal cortex downgraded the reward value to discourage further consumption of the snack.
The researchers tested the habit group next. While these volunteers were hungry, the fMRI revealed a big signal from the ventromedial prefrontal cortex, showing a high reward assigned to the food.
But what happened when they were no longer hungry? The fMRI revealed that the activity in the ventromedial prefrontal cortex was just as high as when the volunteers still had their appetites. Their brains failed to dissuade them from eating because the subjects had been pressing the button and eating out of habit, breaking the downgrade cycle. The act of eating became habit instead of dependent upon the need for nourishment.
This ground-breaking research may very well explain why we often eat despite not being hungry. By letting our habit system take over, our eating becomes automatic and unregulated.
It Takes Conscious Awareness to Kick the Habit
So how do we keep the habit system from taking over? We have to always be consciously aware of what we are eating, not letting our minds fall into a routine.
Think of it as the difference between consciously driving a car and driving by habit. If you drive daily to an office or school, it becomes a habit and you think of other things while you are driving. If you are going to a new destination, you have to pay attention to the route and engage your conscious mind to make sure you are on the right path and do not miss a turn. Your mind can focus on driving, or it can think of other things, but it cannot do both.
The same is true for eating. If you are watching a program on your smart device or TV, your mind is focused on the show and not the amount of food you are consuming. Your eating becomes automatic and you continue to eat out of habit, not conscious control of your intake.
The Take Away on Overcoming Overeating
Overeating is unhealthy. Almost everyone will agree to that. It is common knowledge that overeating leads to obesity, digestive issues, and heart disease. What is not common knowledge is that the part of our brain that controls our habits may hold the key to overcoming overeating.
By consciously focusing on your food intake and avoiding distractions that take control of your focus, you can limit the food you consume and avoid overeating – breaking the habit.