Last year an edition of the Journal “Addiction” was dedicated to food addiction. But whether food addiction actually exists is not an easy question to answer.

Sometimes the definition is that use of a substance or participation in an activity continues even after if has a detrimental effect on your life. So you keep taking heroin instead of eating, and that’s detrimental. Could the same be said about food? Certainly, some people are unable to control their eating to the point that it becomes detrimental, leading to health problems like heart disease and diabetes.

Because of course, not everyone who takes drugs becomes addicted, and likewise not everyone who eats does so to consistent excess. Interaction between the substance or activity and the body – some people’s brains react differently. The brain has reward pathways which trigger a dopamine release whenever we do something that was, in our ancestral past, beneficial to out survival and replication.

Have you noticed this trend in “food porn,” where people are taking photos of their food and posting it online? Photo by SteFou

For example, because sugar was rare back then (there was no Cave Mart), and because it was contained in food that was nutritious (that is, fruit), our ancestors who gorged on sugary food when they found it did better – they got more nutrition than those who ate a couple of berries and left it at that.

But now of course, sugary food is not only plentiful, but its correlation with nutrients has diminished greatly. Yes, you can get any fruit you want, but who satisfies their sweet tooth with an apple? No one, we head for the cake and chocolate, and take the fat and other crap that goes with it.

Yet for some people, food isn’t much of a big deal. The reason for that might be variation in this desire to seek out food – when some people eat, they get a bigger dopamine release, a bigger reward response than other people, which encourages eating and keeps calories high.

This has been demonstrated in neuroimaging studies – obese people tend to show altered reward and tolerance responses to food. Though it’s not the whole story as insulin resistance and variations in other hormones also tends to be present. Furthermore, it’s hard to say if the food itself is what’s triggering the changes in reward response, because it’s hard to find people who eat junk food but aren’t also exposed to marketing messages, stress, or have dieted in the past, all of which may mess around with things.

Also, maybe “food addiction” is too broad a term. You don’t see people whose lives have been affected by their inability to stop eating vegetables, for instance. Although sugar addiction has not been demonstrated in humans, fat and salt may have some addictive potential, though there isn’t much data on that yet. And that’s not even mentioning additives and other junk that gets put in food.

So you’ve got a few issues here. First, you have inherent variation in the way people respond to food, neurologically. Then you have environmental factors that change the way people do the same. The people who have a high reward response to food are perfectly fine in certain environments, such as the proverbial active hunter-gatherer lifestyle, but put them in the modern world and things are different because of the things I mention above. Only by combining the two can you get a sensible idea of who’s at risk.

Remember, what we consider to be obviously addictive now was once up for debate a while back, including nicotine and cocaine, and now we’re discussing things like food, gambling, sex and even the internet. Maybe one day we’ll look back and say, yes, when a person has addictive potential x and their in food-abundant-marketing-heavy environment y, they have z per cent chance of displaying addiction. Or in other words, put human population x in environment y will find z per cent of people becoming addicted. Or maybe psychologists are just looking for another disease they can cure you of. 🙂

See also:

Is fast food addictive