Research roundup: Food addiction | Precision Nutrition

Research roundup: Food addiction

By Ryan Andrews, M.S., RD


Imagine that you’ve just finished a satisfying dinner. It was food you wanted. It was nutritious. And you had just the right amount. Life is good.

But then, right after you finished, someone offers you a bowl of raw broccoli. Would you eat it? Would it be tough to resist not eating it?

What about if someone were to offer you a piece of cake? Would you eat it? Would it be tough to resist not eating it?

Let’s be real. Most people aren’t going to eat more veggies after a satisfying dinner. We tend to eat veggies when we are actually hungry. Same goes for most unprocessed, whole foods.

When we start modifying and processing whole foods into flours, cakes, crackers, sugars, and so forth – the palatability factor goes way up – and we don’t just eat them when we’re hungry. We might just eat them for a dose of pleasure.

So – let’s revamp the title of this article:

Research roundup: Edible food-like substance addiction

We’ve examined the question of food addiction in several other PN Research Reviews lately:

Is Food Addiction Real?
Food Rewards and Overeating
Sweet Stealth: Tasteless Sugar Addiction

In these articles, we explored the idea of “addiction” and what it involves, and looked at some of the mechanisms behind it.

The notion of food (or nonfood) as an addiction is now emerging as an important area of research.

Key questions in this field include:

  1. Can we truly be “addicted” to foods in the same way that we could be addicted, say, to drugs?
  2. And more importantly, as noted above, does “food” addiction only apply to certain “nonfood” foods?

Think about your habits, then consider the characteristics of food addiction.

  • Do you overeat cabbage despite consequences to your health? What about pastries?
  • Are you preoccupied with the leftover bean soup in your freezer? What about the ice cream?
  • Have you failed to cut back on pears? What about cheese?
  • Do you feel guilty after eating quinoa? What about cookies?

A bit different. And definitely food for thought, so to speak.

What is food addiction?

There’s no official definition for food addiction, but experts say that food addiction includes:

  • Eating too much despite consequences — even dire consequences — to health and wellbeing
  • Being preoccupied with food, food prep and meals — to the exclusion of normal activities
  • Withdrawing from normal social interaction and activities in order to eat (in other words, you’d rather stay home alone on a Saturday night with a pizza and some ice cream than go out with friends)
  • Trying and failing to cut back on food intake
  • Feeling guilty about eating and over-eating
  • Hiding eating and over-eating

Why study food addiction?

Some folks argue that labeling over-eating as an addiction removes responsibility and free choice. However, I’d argue that studying food addiction will likely bring us to novel forms of obesity treatment, and help us understand why people over-eat despite all kinds of penalties.

What does the research say?

The evidence in favor of food addiction is beginning to accumulate. I attended a seminar on “food” addiction/overeating in April 2010.

Here’s a glimpse at the notes I scribbled down in my notebook during the lecture (you’ll notice that some are rooted in science and some are just random thoughts):

Eating for reward

One of the most important parts of understanding addiction is understanding the behavior-reward cycle.

Addicts do a certain behavior, and get a certain reward. That reward is somehow more important and compelling than anything else — so despite any negative consequences, addicts will seek that reward over and over and over. Addicts may not like or enjoy their behaviors or the consequences… but the reward has such a strong pull, they can’t resist.

Studying how the brain responds to food as a reward, and then reinforces behavior that leads to that reward, is a recent area of study and has encouraged further study into food addiction. Before brain responses to food were studied, we were a tough love world. We told people: eat less and move more — duh! Now we’re realizing that maybe it isn’t so simple.

Hormonal control of appetite

Knowing more about appetite hormones and neurotransmitters in particular has contributed to our awareness of food addiction. While the way we think and feel about food is also very important, we now know that hormones shape our hunger responses, perceptions, and behaviors too.

This is recent stuff. To give you an idea, ghrelin was discovered in 1999 – the same year I graduated high school. (For more on this, see All About Appetite Regulation.)

Dopamine and rewards

Dopamine is the “wow” of life. It’s the brain chemical (aka neurotransmitter) that is involved in rewards and gratification. It gives us the “high” when we win big in Vegas, find a fabulous pair of shoes on sale, or are taking our first bite of a Cinnabon. What lights up dopamine best? Food, sex, and drugs. (Probably rock ‘n’ roll is in there too.)

The brain remembers what triggers dopamine. Once a dopamine reward is given, the brain then helps us seek out that reward again by repeating the behavior. The more we repeat the behavior, the more the reward is ingrained.

The more junk you eat, the more junk you’ll eat.

But the converse is true too — the less junk you eat, the less junk you’ll eat. Cravings stop going where they aren’t fed.

Variety really is the spice of life

We also seem to have sensory specific satiety that is additive. We like more rather than less; fancy and varied rather than plain.

This means we’ll eat more from a bowl of Chex Mix than a bowl of only pretzels. We’ll eat more from a bowl of trail mix than a bowl of only almonds.

We prefer particular tastes and textures — and we love them together. We like the taste of sugar and salt, and the “mouth feel” of fat, for instance. And we’ll eat more when tastes and textures are combined (salty and sweet; crunchy and creamy, etc.) Food manufacturers and restauranteurs know this — so they create foods that combine variety.

Think nachos with cheese and sour cream: salty, tangy, creamy, spicy, crunchy…

Or you may think you like chocolate, but in fact, what you really like is the creaminess and sugar with a tiny hint of bitterness. Most folks don’t get hooked on raw cacao nibs or 100% pure cocoa powder.

Some researchers speculate that artificial sweeteners may raise our “sweet threshold” — changing our taste expectations so that like addicts who seek out stronger and stronger hits, we seek out sweeter and sweeter tastes; we aren’t satisfied with things like the sweetness of fruit.

We also eat more when we have more choices, such as during buffets, potlucks, holidays, etc.

Sex, drugs, and chocolate

Compared to food and sex, drugs create a much stronger dopamine response in the brain… although the dopamine response for food and sex is similar. Just like drugs hijack the brain, evidence suggests that chronic consumption of refined foods can have a similar impact (with weaker effects). Food acts like a drug, and we act like junkies. And we may learn to use food to soothe ourselves or avoid unpleasant emotional states.

Bad day at work? You could have a few drinks. You could smoke half a pack of cigarettes. Or you could have a tub of Haagen-Dazs. What’s the difference?

There’s also evidence that some folks may be more predisposed than others to engage in addictive behaviors. For instance, up to 50% of individuals with disordered eating abuse alcohol or illicit drugs, compared to 9% of the general population.

The fun factor

We’re pleasure seekers by nature. This is one reason why “eat less and exercise more” isn’t compelling. It doesn’t seem rewarding. It doesn’t seem fun.

If your life isn’t pleasurable, you’ll find pleasure elsewhere.

It’s important to get “highs” from daily living (job, family, friends, hobbies, exercise, etc.), not just “highs” from food.

Why restriction fails

New evidence suggests that what we call “willpower” — or our ability to delay gratification, control our behaviors, and manage irrational urges — is a finite resource. If we expend a lot of effort on self control, we run out… and that’s when we start engaging in problem behaviors.

This is one reason why strict dietary restraint usually results in over-eating; why skipping breakfast catches up to us in the evening; and why long gaps between meals result in knucklehead food decisions.

So don’t set yourself up for failure by creating and trying to enforce a host of complex, strict food rules. Create a structure and environment that allows you to succeed without really trying. (For example, see All About Kitchen Makeovers.)

Furthermore, diets don’t address why we’re overeating in the first place. The things we come to crave are, for the most part, things we have experienced and found reinforcing in the past. Just telling ourselves we won’t eat the things we crave isn’t enough.

The role of body composition

With eating and body fat, we don’t always know what comes first. For example:

  • Is it the lack of dopamine receptors in the brain that causes overeating and obesity, or is it overeating and obesity that causes a lack of dopamine receptors in the brain?
  • Are some people born resistant to leptin, or do people eat too much, get fat, and then become resistant to leptin?
  • Do we get stressed and then get fat? Or does the extra fat on our bodies cause stress?

What we know so far

While we wait on some final answers, there are some things we do know for sure.

Processed food is a problem

Our bodies respond differently to processed vs whole foods. “Carbs” aren’t the problem, “processed carbs” are.

We love fat, sugar and salt. Think about how these components alter otherwise healthy whole foods. And think about how these alter your response to foods in general.


Corporations are invested in our over-eating cheap, mass-produced foods. Their goal: to get you coming back for more… lots more. In fact, brand loyalty can be established by the time a child is two. If we only ate unprocessed foods that promoted health, countless food companies and restaurants would go out of business.

Aroma chemists make $250,000 per year. The average family farm household income is $76,000.

“Treating” the problem

If we can acknowledge food as a potential addiction, it will be helpful for how we might go about handling eating.

“Treatment” for poor nutrition is simple. We build knowledge, form a plan, and execute the plan.

“Treatment” for an addiction is quite different. Calorie knowledge and grocery store tours don’t do much good. Addiction involves a major psychiatric and spiritual component.

Summary and recommendations

While the jury is still out on whether food (or nonfood) consumption can truly be an “addiction”, thinking about it this way helps us understand seemingly irrational behavior — such as over-eating until it hurts.

Addiction thrives on patterns. We tell our brains what we want by “grooving” habits. For example, the more junk you eat, the more junk you’ll eat. But the converse is true too — the less junk you eat, the less junk you’ll eat. Cravings stop going where they aren’t fed.

Restriction and “willpower” alone aren’t the answer. We need to structure our routines and environments to help ourselves succeed.

And we need to address the underlying causes of our behavior. Food has chemical effects, but addictions are also coping mechanisms.

Opt for unprocessed, whole foods. Our bodies respond to these differently than they respond to sugar, fat, and salt bombs.

Note: Thanks to Dr. Lacye Ratliff for the lecture.

Further resources

Research Review: Is Food Addiction Real?

Research Review: Food Rewards and Overeating

Research Review: Sweet Stealth: Tasteless Sugar Addiction

How “Instant Gratification” Delays Your Results

How Do You Change Your Behavior?

Yale Rudd Center for Food Policy and Obesity has several podcasts about food addiction

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