The science of overeating: The good, the bad, and the ugly

I’ve been writing about the emotional journey of my weight-loss project, but obviously there’s more to weight loss than emotions.

There’s also science.

I recently found a book that does a great job explaining the science of overeating, and today I’d like to share with you some of what I’ve learned from it.

The book is called “The End of Overeating: Taking Control of the Insatiable American Appetite.” It’s by a former US FDA head, David Kessler, MD.

You can get the book on here.

In this post I’ll share some of the quotes from the book that really struck me, and my thoughts about them. But be aware — there’s a lot in this book I won’t be sharing with you. I won’t be sharing his research about how the food industry works to “load and layer” food so you’ll become addicted to it. I won’t be sharing the theory of treatment of “Conditioned Hypereating.” I won’t be sharing many other parts of the book. If you like this blog post, “The End of Overeating” may be worth checking out.

Americans weigh more, and eat more

Did you know that Americans didn’t used to be fat? It’s true. According to Kessler, as early as 40 years ago, weight was generally pretty stable across a person’s adult life. “American adults typically gained a couple of pounds between 20 and 40, then lost of couple of pounds in their 60s and 70s.” That was it.

Things have changed. Kessler points out that, in the 40 years between 1960 and 2000, 20- to 29-year-old American women’s average weight has gone from 128 pounds to 157 pounds. At the same time, American women ages 40-49 went from an average of 142 pounds to an average of 169 pounds. And while he didn’t provide the numbers for men, I feel confident that their increase is just as big if not bigger.

Americans are also eating more:

“By far the largest increase has been in the consumption of fats and oils, with a 63% jump over a thirty-three year period, from per capita annual consumption of about fifty-three pounds to about eighty-six pounds. The use of sugars and sweeteners is also up — by a modest 19% — and in that same period we ate 43% more grains and 7% more meats, eggs, and nuts.”

We eat more, and we weight more.

But…Why? Why is this happening? And what can we do about it?

Introducing the “Hyper-palatable 3″: Sugar, Fat, and Salt

Kessler points out that “Early human diets contained only about 10 percent fat. Sugar intake, primarily from ripe fruit, was also modest.” And I imagine early humans intake of salt was modest, too.

These foods are vital in small quantities, but they were rare, so humans developed the ability and the desire to seek them out. “That may be why we have 300 or more olfactory receptors to sense the odors associated with fats, as well as an innate preference for sweetness,” Kessler says.

So what happens when sugary, fatty and salty foods — once rare and pursued — become available in unlimited quantities?

A study at the University of Chicago performed by scientist Anthony Sclafani provides an answer that probably won’t surprise you. Sclafani fed rats a “supermarket diet:”

“[The rats were fed foods including] sweetened condensed milk, chocolate-chip cookies, salami, cheese, bananas, marshmallows, milk chocolate, and peanut butter. After ten days, animals that were fed the supermarket diet weighed significantly more than rats that were fed bland chow. And the rats on supermarket diets continued to gain weight, eventually becoming twice as heavy as their control counterparts.”


But as I said, you’re probably not surprised by this. Most of us have experienced “losing control” against foods high in sugar, fat, and salt.

That’s why Kessler calls sugary, fatty and salty foods “hyper-palatable.”

They’re not simply “palatable” — that is, “good tasting.” They’re “hyper-palatable” — off-the-scale desirable, tasty beyond anything humans have developed resistance to.

And it turns out that, if you eat a ton hyper-palatable food, it’s not because you have some sort of moral failing.

It’s because of biology.

When we go up against sugary, fatty, and salty foods, our biology can easily be turned against us. Then overeating — and getting fat — wins.

This is your brain on heroin opioids

Kessler says that “alone among the senses, taste is hardwired to brain cells that respond to pleasure.”

That means that there are specific neurons that respond to different aspects of the eating experience. Some specific neurons fire when you eat something sweet. Others respond to a certain texture in food. “A neuron stimulated by a sweet taste that has been coupled with a fatty texture would be activated when we eat, say, an éclair.”

When these neurons fire, they trigger the body’s pleasure system:

“When we first put a highly palatable food in our mouths, taste buds in the tongue respond by sending a signal to an area of the lower brain responsible for controlling many of our involuntary activities, such as breathing and digestion. When the lower brain receives that signal, it activates the neural circuitry that contains natural opioid molecules.”

“From the lower brain, the sensory experience of taste travels through the midbrain, reaching regions where the sensory signals of food are integrated. Those signals are ultimately relayed to the ‘nucleus accumbens,’ an area of the brain that is the center of reward.”

This causes the release of opioids into the brain. Also known as endorphins, they have a “rewarding effect similar to morphine and heroin.”

That gives the big burst of pleasure that is familiar to many of us. It’s what we feel when we eat a hyper-palatable food — in my case for instance, a chocolate-chip cookie. The intense pleasure is the opioids being released into the brain.

A vicious cycle: Opioids drive even more eating

Unfortunately, when you eat hyper-palatable foods — foods that are full of sugar, fat and salt — you don’t generally become satisfied.

In fact, eating hyper-palatable food drives you to eat even more hyper-palatable food:

“In a cyclical process, eating highly palatable food activates the opioid circuits, and activating these circuits increases consumption of highly palatable food.”

“Animals eat more high-sugar, high-fat foods after receiving opioid injections. We also know that after using drugs that stimulate the opioid circuitry, people report that palatable food is more pleasant and they eat more of it.”

Not only do the opioids activated by hyper-palatable food stimulate eating more, they also keep you from growing tired of those foods.

You’re never satisfied. You just keep wanting more.

Sugar, fat and salt literally change your brain

I’m not using “literally” to mean “figuratively,” either. As we’ll see in a moment, the cycle of cue/dopamine/opioid/habit/repeat literally changes the way your brain functions in regard to food.

Cues to eat

First, there are the “cues” to eat.

A “cue” is a stimulus that “trips the trigger” and tells you to eat. It’s what makes you think, “Oh yeah, it’s time to eat that now.”

For me, the cue to eat a cookie might be seeing it at the coffeeshop.

Or I might be unaffected by seeing it, but the smell of it, fresh-baked, might cue me to eat.

The more I obey a cue, the stronger and more far-reaching that cue becomes. After enough times of eating a cookie after I’ve seen it, not only will I get cued by seeing the cookie, I’ll also start being cued by driving by the coffeeshop where the cookie is available. Then I’ll start getting cued every time I get into the car. Then I’ll start getting cued to go buy a cookie when I even think about getting into my car.

Kessler says, “With experience, the association between cues and food becomes even stronger, and we become more single-minded in our focus and our pursuit.”

Not surprisingly, he concludes, “That increases consumption.”

Dopamine and the pursuit

When we see a cue, the chemical dopamine is released in the brain.

This releasing of dopamine is like putting your foot on the gas pedal of desire. It makes you go faster in the pursuit of food.

“If opioids give food its pleasure and help keep us eating, dopamine motivates our behavior and impels us toward food.”

When a person gets cued and dopamine is released, they are driven to overcome whatever obstacles might be between them and the goal.

How hard will dopamine drive us in pursuit of hyper-palatable foods? Scientist Sarah Ward, working at the University of North Carolina at Chapel Hill, found this:

“The breaking point where the animals will no longer work for a sugar and fat ‘reward’ is slightly lower than the breaking point for cocaine. Animals are willing to work almost as hard to get either one.”

That’s some pretty serious pursuit.

And again, it’s not a moral weakness if this is happening to you. It’s not you “just being weak” or “needing to try harder.” It’s your brain’s natural reaction to constant exposure to foods full of sugar, fat, and salt.

Habits nail that coffin shut

If you act out a set of behaviors over and over, it will usually become a habit. And, because of the pleasure that comes with the opioid release of eating hyper-palatable foods, habits of eating sugar, fat, and salt are very easy to form.

As Kessler says,

“A continuous cycle of cue-urge-reward is set in motion and eventually becomes a habit.”

“In one study, people were given high-sugar, high-fat snacks for five consecutive mornings. For days afterward, they wanted something sweet at about the same time each morning that they had been fed the snack, even though they had not previously snacked at that time.”

This is serious, because when you have a habit, you can actually take action before you know you are doing it:

“Researchers have been able to measure movement before subjects know they are going to move. Brain activity stimulates a motor response in advance of awareness.”

Have you ever just “found yourself” eating, before you even knew you were doing it? That’s “action in advance of awareness.” It’s part of the effect that hyper-palatable foods have on your brain.

Summing up the science

Kessler concludes:

“Foods high in sugar, fat and salt are altering the biological circuitry of our brains….Rewarding foods are rewiring our brains. As they do, we become more sensitive to the cues that lead us to anticipate rewarding foods.”

“The cycle: a cue triggers a dopamine-fueled urge…dopamine leads us to food…eating food leads to opioid release…and the production of both dopamine and opioids stimulates further eating.”

Kessler has defined this behavior as “Conditioned Hypereating.” It’s a syndrome in which this new brain chemistry has taken control.

In conditioned hypereating, everything seems to become a cue to eat. The cue releases the dopamine, which drives us to eat, which releases the opioids, which drives us to eat more… And the cycle goes on and on, and we get fatter and fatter.

Thinking in terms of 3 types of food: The good, the bad, and the ugly.

As you may recall from a previous post, I very highly value feeling free to make my own choices. Discovering that I was being a puppet in the hands of sugar, fat, and salt really motivated me to change.

As I’ve contemplated this change, I’ve realized that most people see food in two categories:

  1. The good: Food you enjoy. You eat it, because you like it.
  2. The bad: Food you don’t enjoy. Generally speaking, you don’t eat it. You avoid it because you don’t like it.

Before hyper-palatable foods were constantly available to us, these two categories worked just fine. But I believe a third category of food has arisen:

3. The ugly: Hyper-palatable food. Hyper-palatable food is food you enjoy — too much. You don’t eat it because

    • it takes control of your biology,
    • it alters your brain chemistry, and
    • it takes control of your behavior and makes you eat even more.

Since I’ve been thinking of food in these three categories, rather than the old two, it’s been much easier for me to change my eating habits.

Now that I know the truth about hyper-palatable foods, I see them for what they really are. If a food is hyper-palatable, I don’t eat it. It doesn’t matter if its tasty. I don’t need the trouble.

I’ve also come to recognize the feeling I get when I eat a hyper-palatable food. When I eat a hyper-palatable food, I feel an intense pleasure, located in the center of my head, along with the desire to eat more of that food. Your signal may be different from mine, and I encourage you to discover what your signal is.

For me, if I feel that “hyper-palatable pulse,” I stop eating that food right away, because I know it will take control of me if I give it the chance.

The bigger picture

I have some other ideas about the importance of managing your brain chemistry that I’ll discuss in future posts. Today, I’ll simply say that I suspect that there is a kind of brain chemistry that feeds the feeling of deep blessing. I believe that such brain chemistry is actually incompatible with the driven-to-eat brain chemistry that comes from eating hyper-palatable foods.

My suspicion is that you can either be in the “blessed” state of mind, or the “pursue hyper-palatable foods” state of mind — but not both. And because we all want to live from a flow of deep blessing, knowing how to get your brain chemistry right is important.

Put another way, I’m suspecting that the act of making changes in our diet runs down to the core of who we are as people, and directly into our spiritual lives. It’s not just about losing weight. It’s about where we get our sense of sustenance, on the deepest levels.

And that’s a good thing, because I know that I’m not seeking a way to lose weight if it means spending the rest of my life in a battle to keep from getting fat again. If you’re like me, you’re not interested in a life-long battle, either.  So whatever solution I arrive at has to not only work in the long-term, it has to really, truly help me feel like I’m being fed by a deeper blessing current. I think most other people would like that, too.

I’ll talk more about it in coming posts, but I wanted to give you a sense of where I think all this is going.

For now, I suggest you start to think in terms of foods you like to eat (the good), foods you don’t like to eat (the bad), and hyper-palatable foods that cause you pleasure, but which you don’t eat anymore (the ugly).

I welcome your thoughts in the comments.

Sign up here to be notified of future blog posts. (You can unsubscribe with one click from any email I send you.)

About Dmitri


  1. Judy Murdoch says:

    Guess Red Velvet Cake with cream cheese frosting is on the list of Hyper Palatable.

  2. Jane says:

    Very interesting Dmitri. Thanks. I love your concepts of foods that create a blessing feeling vs. those that just increase desire. Ayurveda has a similar concept. Foods that create the feeling of deep blessing or bliss are known as “sattvic” whereas foods that fuel desire and are hyper-palatable are known as “rajasic”. Sattvic foods lead to feelings of calmness, peace and clarity of mind. Rajasic foods promote drama and instability of mind and emotions. As you can probably guess Sattvic foods are things such as whole grains, legumes, fresh vegetables and fruits. Nice when science confirms ancient teachings :-)

  3. Lynnette says:

    I dont eat my old diet but I most certainly remember it. When I read “Eclair” above, it brings me back again, to the hotel door behind which was my Parisian patisserie bag with the Eclair saved for the flight home the next day and forgotten. But remembered since fondly, surrealist, better than an old friend. Opiat, legal and French. I never had a chance. I haven’t been back. Dont feel too bad however as I ‘d bought two and the previous one had lasted a whole train ride long. Enough has a different definition now. 6 grilled shrimp and tomato, quartered hard egg, roasted beef, macerated cucumber, abed arugula, a dust of pepper. Thats breakfast and lunch, appetizer and dinner, or a shared respite taken with teppid water, lemoned and iced, or variations of teas. Followed by the joys. Great memory tho!

  4. Steven Deller says:

    You left out the biggest cuplprit, IMO. That culprit is high-fructose corn syrup (HCFS) and just plain corn syrup which is mostly fructose. The problem is that the metabolic pathway for fructose is different than for glucose.

    Glucose is metabolized in our cells. It is, for all intents and purposes, a “good” sugar. During the metabolism, leptin is produced to tell our brain “I have enough sugar.”

    Fructose is metabolized in the liver which produces fat, destroys the liver (there are now cases of cirrhosis of the liver from sugar metabolisis), and worst of all, there is no production of leptin (as there is with glucose). Without the leptin, we never get the signal to stop eating sugar.

    Sucrose, table sugar, when we first break it down, becomes one glucose and one fructose. The fructose is bad, but at least the glucose produces leptin to tell us “enough!”.

    Honey is basically 1/2 glucose and 1/2 fructose (the bees split the sucrose for us). It does have loads of other trace items, but most of it is those two — again, we at least get leptin produced by the glucose half of the mixture.

    Agave is between 70% and 90% fructose and 10% to 30% glucose. That’s worse than sugar and honey. One saving grace is that the sugars appear to be “bound” in some way so it is hypo-glycemic, meaning it is broken down more slowly. At least that’s what they tell us. And that is also why getting fructose from raw fruit is somewhat better than getting it from HFCS.– the body more slowly loads the liver with the fructose and the glucose-induced leptin is more continuous.

    The food industry started using HCFS about 40 years ago, about the time you said the American obesity fad started (how do you make a sarcastic emoticon?). That was also the time that the US Government started paying farmers to grow corn (they used to pay them NOT to grow things). HFCS was the natural by-product of the explosion in corn production and the explosion of the American waistline was the natural result of that.

    I am on the warpath to remove all HCFS from anything in my kitchen. Out went the ketchup!! Can you believe it? You can’t get ketchup without HCFS (at least I can’t find it). I know they started ketchup back in the early 1900′s before HCFS, but now days you can’t get the good old stuff (Gee — I sound like an old fart :-) ) — and the real old stuff had minimal sugar.

    I’m still hooked on sweets — though I’ve been working, like you, to remove them. It is happening over time. And I’ve gone primarily to Stevia products when I need sweets (the price of Stevia helps keep my desire for sweets in check :-) ).

    Fat is not so dangerous, IMO. I find that very little gives me a real feeling of saiety — and the more I read the more I realize we need some of it in our diets. With fat, I can listen to my body and my taste (when it feels greasy to my tongue, I don’t like it).

    Salt I treat the same as fat — just listen to what my body wants. If I want salt, I eat it (sometimes dump some in my hand and take it straight). For me, salt has no relation to high-blood pressure.

    We do watch the amount of salt in the few processed foods we buy (soups primarily), but that is more a careful listening to what tastes I like and wanting to taste something besides salt. And I don’t “routinely” salt things.

    The body needs sodium (and potassium) for proper muscle function so if I feel I want it, I take it. I remember in the 1950′s that we routinely took salt tablets on very hot days when sweating a lot. If the body needs salt, it needs salt. As for the association of salt with high blood pressure, I beleive that is starting to be de-bunked. The amount of salt in the blood stream has little to no relation to the amount eaten and the correlation with high-blood pressure may be just that, a correlation without any cause and effect. For me, blood pressure mainly has a lot to do with mental stress levels. In spite of being overweight (in the past almost morbidly so), my blood pressure has stayed in the 110/70 to 120/80 range for the last 20 years (I donate platelets every 2-4 weeks so I get my blood pressure taken that often). That correlates well with when I started to de-stress by changing how I reacted to things.

    For me, with regard to obesity, the real cuplrit is fructose and particularly HFCS. We’ll see how it goes now that I’m working hard to remove it from my diet (starting about 6 months ago).


    • Dmitri says:

      Steven – those are great points. I know one doctor who told me he thinks hfcs should be ILLEGAL. 
      For me, sweets are the biggest problem, though I do find I feel better if I limit my intake of oils. 

    • Fawn Bilgere says:

      Keep looking–there is at least one health-food brand of ketchup that uses straight-up sugar.

      (Or make your own, like in the olden days?)

      To your health! :-)

  5. Leslie says:


    I invite you to distinguish oils in terms of their processing. Old-fashioned fats / oils have been processed very little–I mean butter, olive oil, coconut oil, cream, even farm-made lard, and beef tallow. The modern processed oils are primarily rancid–soybean oil, corn oil, sunflower oil, safflower oil, canola oil–these are all modern fabrications requiring high temperatures and other high-stress processes. I find the old-fashioned oils are very satisfying and quieting and healing to my system, rather than heedlessly increasing my desire for them. Coconut macaroon, anyone?

    After all my readings about diet, I think the culprit in this “hyper-palatability” story are modern foods, not old-fashioned fats, natural sugars (like maple syrup or raw honey), or unrefined sea salt. It is the refining that strips the foods of their delicate nutrients and adds funky things like MSG (a neurotoxin) and HFCS. It is the refining that brings us foods that fail to nourish us.

    We need to distinguish between old-fashioned foods and modern foods. If we don’t, we are liable to get our science all screwed up!!

    There are cultures / cuisines which include very high levels of old-fashioned fat and sustain high levels of health, like that of the Eskimo (who traditionally ate very little vegetable or grain or fruit foods, and ate mostly protein and fat, often raw). Beautiful, Irish butter from cows eating their proper food–green grass–is a nourishing food, a primo nourishing food. Probably one of the most “sattvic” foods in the Ayurvedic paradigm, in the form of ghee. The Indian culture has revered ghee as a life- and health-promoting substance for a very long time. We have so many fat receptors because old-fashioned forms of fat were vital sources of key nutrients in the form of fat-soluble vitamins like A, D, and K. Without those vitamins, we are poorly nourished people. Old-fashioned fatty foods have nourished people for centuries, if not millennia. Has anyone heard of the “French paradox” wherein French people eat lots of (old-fashioned) fatty foods and have lower rates of heart disease than many other countries? This is not a paradox but a fundamental truth about what foods nourish and what foods deprive. Nourishing diets will always include a source of old-fashioned saturated fat, like butter, ghee, coconut oil, eggs, cream, beef, and so on, among other nutrient-dense, real, whole foods.

    • Leslie says:

      One way to learn more, if anyone cares to do so, is to read what is in

      “The Liberation Diet: Setting America Free from the Bondage of Health Mis-information,”
      by Kevin Brown and Annette Presley, which is a pretty easy read, among other great reads like the “Good Calories, Bad Calories” mentioned above.

    • Jane says:

      Great point about “old-fashioned” healthy fats. They are necessary and important to health. And the current “fear of fat” can have unhealthy consequences if taken too far. A healthy diet is a balance of all the food groups and the six tastes (sweet, salty, sour, bitter, pungent and astringent). It is also appropriate for the constitution and digestive strength of the individual. Eg, some folks definitely do better with more fat in their diet than others (people who tend to be very thin, cold and dry for instance). And as fat, even good fat like ghee, can be hard to digest, it is best to eat only when one has a strong digestive “fire” and is able to digest it with no gas, bloating etc after eating.

    • Dmitri says:

      @Leslie — great point about oil. My wife once went off all HEATED oils to help her heal a chronic condition (it worked). I don’t mean to say that all oils are bad — just that the refined, heated oils that are loaded into so many of our foods are probably not a great idea. (And I also I find that I’m feeling better — and losing weight — keeping away from them).

      I’ll check out the book you recommend!

  6. Jase says:

    Great stuff! Thanks!


  1. [...] flour and added sugar.  Never did I think that a “whole food” could be “hyperpalatable“ the same way sodas and candies are. Perhaps they’re hyperpalatable because of the [...]

Speak Your Mind