The Behavioral and Neurological Evidence for Food Addiction

Can a person really get addicted to food like they can to drugs or alcohol?

A growing body of research suggests that highly palatable foods work very similarly in the brain to substances like drugs or alcohol and that in some cases, susceptible people are at risk of developing food addictions.

In fact, a recent snowballing of findings supporting the concept of food addiction led the director of The National Institute of Drug Abuse (NIDA) Nora Volkow to comment this year that, "The data is so overwhelming the field has to accept it. We are finding tremendous overlaps between drugs in the brain and food in the brain."

What is this evidence on food addiction that researchers find so compelling?

The evidence supporting food addiction falls into three basic categories:

1. Behavioral evidence (people addicted to food and to drugs act display similar types of behaviors)
2. Animal model studies
3. Neurological studies

Behavioral Evidence Supporting the Idea of Food Addiction

People addicted to food display similar behaviors as people addicted to drugs or alcohol, including some which are traditionally used to diagnose the presence of substance addictions, such as:

• Continuing to overeat despite suffering negative consequences from their behaviors
• Experiencing cravings for certain types of foods (fatty or sugary foods, for example)
• Recognizing problematic eating patterns and trying to cut down, but being unable to¹

Although it ‘s hard to understand how a person can get addicted to food, especially since food addiction seems a relatively new phenomenon, it is worthwhile to note how much the food we eat has changed over the last few decades. Today’s grocery shelves are laden with products unknown to consumers of even recent decades and a significant percentage of these new products are highly processed and engineered to be highly palatable through the use of large amounts of sugar, fats, sodium and other food addictives.²

• People addicted to food are generally addicted to ‘hyperpalatable foods’. These foods tend to be highly processed and contain much higher quantities of fat, sugar or sodium than typically found in less refined or more natural foodstuffs.

Animal Model Studies

Rats Given a Choice between Cocaine and a Very Sweet Solution Choose the Sweetness

Researchers in Bordeaux did an animal study using rats that could press a lever to receive either an IV cocaine infusion or a small amount of a very sweet solution.

The rats preferred the sweet solution over the cocaine, even when they had grown to be cocaine dependent. Although previous animal studies have shown that animals will choose cocaine over food, even when they are starving to death, the researchers note that the food typically offered in other studies was not comparable to the super sweet solution used in their research study.

The study authors also note that humans have evolved to seek out sweet tastes. Having taste receptors for sweetness and enjoying feelings of reward after consuming sweet and energy dense foods likely offered an evolutionary advantage in a natural world with scarce naturally sweet foods available. They postulate that because today’s diet can be very heavily loaded with sugars and because this can lead to a super-activation of food reward mechanisms that it is not surprising that some people would experience compromised neural self control regulation and addictions to food.³

Neurological Studies

So people with potential food addictions behave similarly to people with chemical addictions and animals seem to get addicted to highly palatable foods just like they get addicted to highly rewarding drugs, but is it really the same thing at all? At the neural level, can food really be doing the same thing to our brains as drugs like alcohol or cocaine?

Well, neuroscientists don’t yet claim to have a complete understanding of all the processes that contribute to the formation and maintenance of an addiction, but based on what they do know, the answer seems to be a qualified yes – highly palatable foods seem to do similar things to the brains of people with food addiction as drugs and alcohol do to the brains of people with chemical addictions.

For example:

Milkshakes Cause Similar Neural Activation among Food Addicts as Drugs Do for Those with Chemical Addictions

Yale University researchers gave lean and obese study subjects an assessment to measure for food addiction. These subjects where then given MRI scans while they anticipated a chocolate milkshake and while they drank the chocolate milkshake.

During the anticipation phase, people who scored high on measures of food addiction had high activation in areas of the brain that are associated with motivation and reward, such as the anterior cingulate cortex, medial orbitofrontal cortex, amygdala, dorsolateral prefrontal cortex and the caudate. This is very similar to what is seen when drug dependent subjects are shown drug cues and anticipate drug use and it helps to explain why people with food addictions can have a tough time overcoming food cues.

Also, while drinking the milkshakes, study subjects who scored very highly on measures of food addiction had less activation in areas of the brain that regulate inhibition.

What seems to happen is that consuming a small amount of highly palatable food causes the brain to reduce activation of areas of the brain that work to inhibit our impulses (for example, though you might have an impulse to eat a chocolate bar, you can usually inhibit this urge if you know you are trying to lose weight). This could be a neurological explanation to partially explain food binging and it is also something (drug priming) that is seen in people with substance addictions.

So when thinking about food, people who scored highly on measures of food addiction have much greater activation in areas of the brain that focus on motivation and achieving rewarding stimuli, and when consuming highly palatable food, people with high food addiction scores have much less activation in areas of the brain that control impulses.⁴

Why Does Research on Food Addiction Matter?

Obese people who are also addicted to food may not respond well to traditional methods of encouraging weight loss and weight management. If food addiction is real, then it is important to develop ways to identify people with the disorder and to develop pharmaceutical and psychotherapeutic tools to help people manage food cravings and to control binging and compulsive overeating. ⁵