• Your life and health are your own responsibility.
• Your decisions to act (or not act) based on information or advice anyone provides you—including me—are your own responsibility.


Mechanisms of Sugar Addiction: Or, Why You’re Addicted To Bread (Updated)

(This essay is Part I of a series on carbohydrate addiction and the myth of ‘complex carbs’. You can skip to Part II, “Adjacent To This Complete Breakfast!” or Part III, “The Myth Of “Complex Carbohydrates”.)

Why do we crave the empty calories of bread? Answer: for the same reasons we crave the empty calories of candy.

Bread = Skittles

I’ve made the point before that bread—even whole wheat bread—is metabolically equivalent to Skittles, because it has the same glycemic index. You get the same sugar rush from a ‘healthy’ whole wheat bagel that you do from candy…and though it might not taste as sweet, it’s all the same to your digestive and metabolic system.

Whole-grain bagel: 280-350 calories, glycemic index 72.

Bag of Skittles: 250 calories, glycemic index 70.

(Calorie counts: bagel, Skittles. Glycemic index table here.)

A short layman’s explanation for those unfamiliar with food chemistry: “proteins” are just amino acids linked together in chains, and “carbohydrates” are just simple sugars (glucose, fructose, galactose) linked together in chains. When a carbohydrate is small (two simple sugars) and tastes sweet, we call it “sugar”—and when a carbohydrate is big (many simple sugars) and doesn’t taste sweet, we call it “starch”. But it’s all the same thing: “carbs” are just sugar, and your body breaks them all down into simple sugars before using them.

“Glycemic index” is a measure of how quickly the sugar in a food (including starch and other “carbohydrates”) appears in our bloodstream, fully disassembled, after we eat it. The higher the glycemic index, the quicker the sugar hit.

Note that white rice has a higher glycemic index (64) than Coca-Cola (58), and ‘healthy’ breakfast cereals like cornflakes (81) and Grape Nuts (71) have a higher glycemic index than a Snickers bar (55)! Read this list of 100 common foods: you’ll be surprised at which “healthy” foods are really just sugar bombs.

Interestingly, there is no special dietary name for short proteins: they’re all just called “protein”.

(A giant table of glycemic index for thousands of foods can be found here.)

Eating Like Cattle, Getting Fat Like Cattle

We are told to eat lots of ‘carbohydrates’ (sugars) in small meals throughout the day, as recommended by the nutrition industry (the ADA, most Western governments, and other wholly-owned subsidiaries of multinational agribusinesses and drug companies). In other words, we are told to graze—like cattle.

Grazing like a cow means that your bloodstream is always full of sugar. Glucose (a simple sugar) is our body’s primary energy source, and our bodies will always use it first if there is any available. We only start metabolizing fat for energy when there is no sugar left.

Unfortunately, by maintaining such a diet, our ability to metabolize body fat simply atrophies—because it’s never used! This is why dieters feel so desperately hungry, and why it’s hard to reduce ‘carbohydrate’ (= sugar) intake: we’ve got plenty of energy available in the form of body fat, but our body’s ability to metabolize it has atrophied—so we are metabolically starving in the midst of plenty. It’s like having a pantry full of canned tuna and discovering you’ve lost the can opener.

In the scientific literature, the ability to switch back and forth between glycolysis (burning sugar) and beta-oxidation (burning fat) is called “metabolic flexibility“. And while the above paragraph is simplified to avoid dragging my readers into the technical and biochemical details, the adventurous and inquisitive can learn more by viewing my 2013 Ancestral Health Symposium presentation “What Is Metabolic Flexibility, and Why Is It Important?” and the references in its bibliography.

This is the metabolic component of sugar (‘carbohydrate’) addiction.

(See this short cartoon for Tom Naughton’s entertaining layman’s guide to this metabolic catastrophe, which includes Type II diabetes in its end stages. I also recommend watching his full presentation “Big Fat Fiasco”, also available on DVD here.)

The Sugar Rush: Chasing Serotonin and Dopamine

There is a second component to sugar addiction: not only are sugars (‘carbohydrates’) metabolically addictive, they are most likely physically addictive too. Here’s how that works. (You can skip to the summary below if you’re not interested in the details.)

“Carbohydrates, when digested by the body, are effectively broken down into sugar molecules. When these molecules are absorbed and released in the bloodstream, blood concentration of glucose increases. Almost immediately, there will be a significant increase in plasma insulin levels as a result of the pancreas releasing its stored insulin. Insulin then steps in to do what it is genetically programmed to do–it breaks it down some more to produce energy and transport the extra glucose from the blood to the body cells. Insulin also makes it easy for tryptophan to enter the brain by eliminating its other amino acid competitors.
“The concentration of the majority of the amino acids, including alanine and glutamine, are significantly reduced each time insulin is secreted. Tryptophan is then able to enter the brain at a higher rate. An increased level of tryptophan in the brain means more available tryptophan for conversion. Tryptophan undergoes hydroxylation to the 5 positions and is converted in 5-HT and eventually to serotonin.” -“Why Carbohydrates Instantly Increase Serotonin Levels”

The science behind this explanation:
PM Lyons and AS Truswell. Serotonin precursor influenced by type of carbohydrate meal in healthy adults. American Journal of Clinical Nutrition, Vol 47, 433-439

In summary: sugar (carbohydrates) boosts brain tryptophan levels, which makes us sleepy. This tryptophan boost increases brain serotonin levels over time, which makes us feel content and satiated (“food coma”). Furthermore, the immediate reward of eating palatable food is a dopamine rush: the same neurotransmitter behind drug highs like cocaine and amphetamine.

(In case you’re not familiar with serotonin: you’ll note that the common antidepressants (Prozac, Zoloft, etc.) are all SSRIs—selective serotonin reuptake inhibitors—which boost serotonin by blocking the body’s ability to reabsorb it.)

The problem is that, like any other addictive drug, the positive effects of bread (and other high-sugar foods) diminish over time—while the addiction remains.

The Journal of Neuroscience, September 29, 2010, 30(39):13105-13109. Weight Gain Is Associated with Reduced Striatal Response to Palatable Food. Eric Stice, Sonja Yokum, Kenneth Blum, and Cara Bohon

“Results indicated that women who gained weight over a 6 month period showed a reduction in striatal response to palatable food consumption relative to weight-stable women. Collectively, results suggest that low sensitivity of reward circuitry increases risk for overeating and that this overeating may further attenuate responsivity of reward circuitry in a feedforward process.”

Rephrased in simple language: the fatter you get, the less of a good feeling you get from eating tasty foods. (And here’s some rat science on striatal dopamine receptors, for those curious about the mechanisms.)

So we eat more and more ‘carbs’ (sugar) in an effort to recreate that dopamine rush and subsequent serotonin contentment…but as we gain weight, we get less and less of that reward. All we get is the sugar spike and subsequent metabolic crash.

Interestingly, alcohol apparently has a similar mechanism of addiction: it increases serotonin nerve activity, but depletes actual brain serotonin. See: Adv Exp Med Biol. 1999;467:265-74. Tryptophan metabolism in alcoholism. Badawy AA. And it is perhaps not a coincidence that women with a family history of alcoholism are more likely to be obese.

Further Reading (optional):
Carbohydrate craving: a double-blind, placebo-controlled test of the self-medication hypothesis. Corsica JA, Spring BJ. Eat Behav. 2008 Dec;9(4):447-54.

Psychobiological effects of carbohydrates. Spring B, Chiodo J, Harden M, Bourgeois MJ, Mason JD, Lutherer L. J Clin Psychiatry 1989 May;50 Suppl:27-33

The effect of carbohydrates on affect. Larry Christensen, PhD. Nutrition Volume 13, Issue 6, Pages 503-514 (June 1997)

“…Carbohydrate consumption is relevant for individuals experiencing symptoms of emotional distress, particularly symptoms indicative of depression, and that the individuals with depressive symptoms show a preference for sweet simple carbohydrates.”


In summary, carbohydrates are addictive in two ways, both factually established:

  • First, because they’re really just sugar, and we get the same sugar rush from bread that we get from candy.
  • Second, because sugar pumps up dopamine and serotonin levels in the short-term—but, like any addictive drug, the reward diminishes over time, while the compulsion to eat ‘carbohydrates’ (sugar) remains.

Breaking Our Bread Addiction

So how do we break our bread addiction?

There is good news! My experience, and that of most people attempting a paleo diet (which is ‘low-carb’, or low-sugar, by definition, unless you’re making a concerted effort to eat potatoes), is that you can indeed regain your ability to burn body fat for energy—and once you’re ingesting enough protein and B vitamins, your serotonin levels won’t be completely dependent on eating sugar. (Eat more meat and eggs.) The relentless sugar cravings slowly dissipate over a couple weeks.

You’ll find that not only do you not crave huge piles of empty sugar calories (bread, pasta, potatoes) with meals—as a bonus, you’ll find that it’s suddenly much easier to go without food entirely, because your body is learning how to burn fat again! You’ll be able to skip a meal without feeling like you’re going to die of hunger…and you’ll also discover that being a little bit hungry substantially boosts your mental capacities due to the action of ghrelin, once you’re no longer distracted by hunger pangs.

Though I can’t find any human studies (since it’s difficult to measure brain tryptophan and serotonin levels without dissecting the brain), there is suggestive evidence from animal studies that fasting raises brain serotonin:

Changes in brain serotonin metabolism associated with fasting and satiation in rats. J. Pérez-Cruet, A. Tagliamonte, P. Tagliamonte and G. L. Gessa. Life Sciences Volume 11, Issue 1, Part 2, 8 January 1972, Pages 31-39

“The synthesis rate of brain serotonin was about 30% lower in rats fed for two hours than in rats fasted for 24 hours.”

Also see Br J Pharmacol. 1984 October; 83(2): 357–362. The effect of fasting on 5-hydroxytryptamine metabolism in brain regions of the albino rat. L. D. Fuenmayor and S. García. [Note: 5-hydroxytryptamine = serotonin.]

There are still unanswered questions here: how long do we have to go between meals to produce a rise in serotonin? (It might happen after an hour, three hours, or twenty hours.) Is abstaining from sugars (‘carbs’) sufficient, or must one fast altogether? More research is needed here: if you know of any that I’ve missed, please leave a comment.

My non-scientific advice is: don’t try to go cold turkey, but do make a strong effort to replace sugars (‘carbs’) with real food whenever you can. Cook bacon and eggs for breakfast, grab hard-boiled eggs or dinner leftovers if you’re on the go, and if you must have that piece of buttered toast, go for it—because it’s still infinitely more satisfying and nutritious than a breakfast of cold cereal or a bagel. It’s better to be happy and calm than a stressed-out diet purist. But as you slowly reduce your sugar intake, you’ll find that you miss candy (and its metabolic equivalent, bread) less and less…

…and you’ll enjoy life more and more without your sugar (‘carbohydrate’) addiction.

Live in freedom, live in beauty.


(This essay is Part I of a series on carbohydrate addiction and the myth of ‘complex carbs’. Continue reading Part II, “Adjacent To This Complete Breakfast!”)

Postscript: Paleo Is Not Atkins, Nor Is It Zero-Carb

The paleo diet is not Atkins, nor is it zero-carb. The best research I can find shows that modern hunter-gatherers get perhaps 1/3 of their calories from carbohydrate, and Paleolithic hunter-gatherers somewhat less. This means vegetables, including root starches like sweet potatoes: grains were not a meaningful part of the human diet until agriculture, of which the earliest evidence is only 12,000 years ago. (This is a tautology: agriculture defines the transition from Paleolithic to Neolithic.)

“In this review we have analyzed the 13 known quantitative dietary studies of hunter-gatherers and demonstrate that animal food actually provided the dominant (65%) energy source, while gathered plant foods comprised the remainder (35%).” Eur J Clin Nutr. 2002 Mar;56 Suppl 1:S42-52. The paradoxical nature of hunter-gatherer diets: meat-based, yet non-atherogenic. Cordain L, Eaton SB, Miller JB, Mann N, Hill K.

(Did you enjoy this article? Use the icons below to spread it! Then, continue reading Part II.)

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Permalink: Mechanisms of Sugar Addiction: Or, Why You’re Addicted To Bread (Updated)
  • Barbara Lamar

    Your theory of metabolic “atrophy” is interesting, but a more straightforward explanation of sugar addiction would be that the ingestion of concentrated forms of sugar (e.g. breads, pastries, candies) stimulates insulin production, which reduces the level of sugar in the blood, leading to symptoms of low blood sugar, which prompt the addict to eat more sugar. If my understanding is correct, insulin also promotes the storage of fat (see Philologic Effects of Insulin http://www.vivo.colostate.edu/hbooks/pathphys/endocrine/pancreas/insulin_phys.html). Of all the published diets I’m aware of, the ones that make the most sense in metabolic terms are the various forms of the Paleo diet, and the South Beach Diet. The South Beach diet discourages grain consumption, but unlike the Paleo diet, it includes dairy products.

  • Barbara:

    That’s what I thought, too—and the blood sugar crash is the commonly accepted explanation for post-meal fatigue. (Your understanding of insulin and sugar metabolism is correct AFAIK.)

    However, the paper “Psychobiological effects of carbohydrates”, which I cited above, notes the following:

    “Only the carbohydrate meal significantly increased fatigue, which could not be attributed to hypoglycemia because plasma glucose remained elevated. Fatigue began approximately, when the carbohydrate meal elevated the plasma tryptophan ratio but ended even though the ratio remained elevated. Fatigue after a high-carbohydrate lunch could not be explained by reactive hypoglycemia or sweet taste, and could partially be explained by the hypothesis that fatigue parallels an elevation of the tryptophan ratio.”

    This makes sense: the fatigue from a high-carb meal appears relatively quickly, long before all the sugar can be metabolized. The effects of low blood sugar arrive much later, and manifest as hunger cravings—specifically for sugars (= carbohydrates).

    But this doesn’t explain why sugar addicts feel this hunger and its associated cravings so much more intensely, which is the central puzzle that I’m trying to solve. They have a compulsion to gorge on sugar (including high-GI carbohydrates like bread and potatoes)—causing massive insulin releases and consequent fat storage, which is (by the empirical evidence) a positive feedback loop ending in obesity and Type II diabetes.

    The fact that sugar (= carbohydrate) addiction is apparently self-reinforcing demands explanation—as does the fact that paleo/South Beach/other low-carb diets empirically work better than low-fat diets, and that carb cravings generally decrease over time for people who follow paleo/low-carb diets.

    Thus my explanation above.

    It’s becoming apparent that everything from muscle strength to cognitive capacity is maintained by our body on a ‘use it or lose it’ basis. My theory is that the ability to efficiently metabolize fat for energy is no different, and that a gradual atrophy of this ability accounts for the observed data.

    (Thank you for helping inspire this essay, by the way.)

  • Yossi

    What do you mean by “bread”.

    There are many, many types of bread, no doubt having various glycemic indices. Has there ever been a comprehensive research program to measure this?

    You are probably referring to the most common commercial “bread substitute” made from highly refined, denatured wheat flower, sugar, yeast, chemicals, etc.

    But what about real sour dough breads made with organic stone ground grain such as wheat, spelt, rye, etc. Or, even better, sprouted grain Essene or Ezekiel breads?

    A macrobiotic style diet, based on whole grains has been shown to be very effective and nourishing.

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  • Yossi:

    Store-bought white and whole wheat bread (and bagels) both have the same glycemic index: 71-72.

    Bread made from other grains tends to have a somewhat lower glycemic index, down in the 50s and 60s…but that’s still up there with Coke and Snickers. I can’t find any information on sprouted grain breads.

    Interestingly, flour tortillas have a lower glycemic index than any other bread or grain product…most likely because of the fat required to make them.

    Note that fat slows gastric emptying and intestinal absorption. Thus, low-fat diets are not only high-sugar diets by definition…they increase the effective glycemic index of all those ‘carbs’ (sugars), causing greater metabolic spikes and greater physical addiction! I believe this to be a primary reason why the “fat is evil, don’t eat it” message from the 1970s and on was immediately followed by rampant obesity and diabetes. I suspect another post on this issue will follow soon.

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  • Robbo

    Great stuff !
    The one point I would argue with is “My non-scientific advice is: don’t try to go cold turkey”

    In my view breaking the sugar / starch addiction is about training your body to use body fat and ketones as power sources, and to train your mind in new habits of eating, actually a new perception of what is food and what is not food. Certainly in my case, in the first few weeks while I was establishing the new habits, I found it very powerful to say to myself and others “I don’t eat sugar / starches”, and refuse the bread / cake / pie / nachos /soda etc. Saying “I’m trying to cut down on sugar / starch” inevitably sets up “but, just for now” and there you are starting to undermine your new habits and revert to your old ones. Of course once the new habits are properly established going off-piste a little is no harm, as long as it is not so long extended as to form a new habit in itself, but frankly I look at a lot of what people around me eat and instead of thinking “I wish I could have some of that but my diet won’t let me” my response is “Wow, you actually think that stuff on your plate is food ?”.

    My personal journey to Paleo was via Atkins, and Atkins induction is pretty much carb cold turkey. Whereas I agree Atkins was wrong on sugar-substitutes like sucralose (to me they reinforce the sugar habit) and he missed the seed-oils issues, he deserves massive credit for popularising low-carb in the face of vitriolic opposition.

  • Robbo:

    Thank you for sharing your experience!

    I suspect there is a great deal of individual variation here.  My experience was that if I tried to cut sugars out entirely, my body simply couldn't burn enough fat to stay awake, and I either walked around in a daze or fell asleep.  So my problem wasn't as much the temptation to eat sugar ('carbs') as it was retraining my body to burn the fat.

    In your case, however, I can understand why you'd need to go cold turkey.  I think it's a matter of which is stronger: the dopamine/serotonin reward motivation, or the blood sugar metabolic motivation.  If the reward circuit is stronger, 'cheating' is bad; whereas if the metabolic motivation is stronger, 'cheating' may be necessary to get you through the day until your body improves its ability to burn fat and ketones.

    That's an interesting issue, and I'm glad you brought it to my attention.  I may revise the article if I can figure out a succinct summary.  

    Please continue to read articles and contribute comments!  There's a new one up right now, and a big update coming on Tuesday.


  • Cornelius

    Great article. A couple of minor quibbles, however. Regarding “…Paleolithic hunter-gatherers got perhaps 1/3 of their calories from carbohydrate,” it should be noted that this depended on where those hunter-gatherers lived. My own ancestors, for example, had much less opportunity to find fruits, veggies, and tubers while following buffalo herds on the plains than did other societies that lived in more tropical climes.

    Also, I don’t think the ability for the body to attain ketosis and start burning fat reserves can really be said to have atrophied, it is just that this switch is almost never thrown anymore. Nowadays we can pretty much get any sort of food we want, all it takes is a trip to the local supermarket, so we never go into seasonal ketosis.

    However, in Paleolithic society, everything except meat was seasonal. Hunter-gatherers would gorge themselves on sweet fruit, for example, when it was available. It was a good source of vitamins, and it was a good thing to go into winter with a little extra fat as insulation. But, once that source of carbohydrate was gone, it was gone, and ketosis set in, allowing our hunter-gatherers to emerge into spring lean and ready for the next big hunt, move to the spring camp, or whatever.

    Our bodies evolved in such a way that they would fatten up for winter, and lean down for summer. In fact, for most of our history, we had little choice, assuming gathering was good. This, I think, is the reason we like sweets. It was for fruit, not candy. Fruit was good for us, in moderation, so it tasted good. But to many, if sweet is good, even sweeter is better.

    Now, we no longer need to hunt, gather, or eat seasonally. So, we just keep eating whatever we think tastes good, and getting fatter.

    Regarding cold turkey or not, I think it may depend on how much carbohydrate you were used to eating. As far as actual sugar goes, I was never allowed much as a child, and that carried over into my adult life. Once in a great while I would get a hankering for a candy bar or somesuch, but I literally only ate like two or three a year. The same goes for chips, and snacks in general. So for me it was pretty much a question of laying off the bread and potatoes. Cold turkey was not too difficult for me. It just meant more meat or more steamed veggies slathered in guilt-free real butter. Yum. :)

  • Cornelius:

    I think you're correct: the seasonal nature of food is a very overlooked part of the metabolic puzzle. Fructose in excess is certainly a metabolic problem…but hunter-gatherers didn't necessarily have year-round access to fruit.  Neither did they have access to domesticated sugar bombs like apples, pears, and bananas, which have been bred for thousands of years for sugar content.  And they most certainly didn't have access to table sugar (1/2 fructose) or soft drinks!  

    So gorging on fruit when it was available was most likely not a metabolic issue for them, and humans didn't ever need an “off switch” for their sugar appetite.  This is suggested by the fact that fat induces satiation but sugars do not: apparently it was possible to eat too much fat, so our bodies have an “off switch” for that.

    Keep in mind, though, that humans primarily evolved in Sub-Saharan Africa, where seasons don't mean the same thing.  Rains are seasonal, and crops are season, but temperatures are far less so.  “Getting fat for the cold winter” is a more recent European adaptation.

    Thank you for all your thoughtful comments and contributions!



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  • Mark

    While those studies show that there is a biological addiction to carbs, it should be mentioned that there is a psychological drive (at least for many people) wherein the desire for carbs is an ingrained behaviour (eating disorders).

    From a neuro-linguistic programming (NLP) perspective for those that don’t have an eating disorder, you could also say that the drive to eat carbs comes from an ‘anchor’

    (Off topic)
    I’m sure you’ve heard about study’s that have attempted to link dopamine release with eating chocolate?

    The question is (both for bread and for chocolate with regards to dopamine) is ‘how do we know anchors are not influencing the result?’

    I remember reading a study a few years ago that stated couples whom described themselves as “madly in love” had similar brain activity to heroine addicts (CATscan).

    My point here is that there is that nothing is being consumed yet dopamine and oxytocin levels were through the roof.

    The psychology of these matters is underestimated and overlooked.

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  • Keith Baigrie

    Is it really the case that hunter gatherers can be so easily claimed as a behavioral bench mark for human eating behavior.

    I also must applaud Cornelius’s excellent point, that there were unrecognized seasonal aspects to be yet to be factored in.

    I recollect that the northern European Vikings, who at the beginning of the last ice age, having earlier colonized Greenland, simply died out by not recognizing the futility of trying to ‘gather’ in continuous snow and ice…whereas the indigenous Inuit, who for thousands of years in the sub arctic didn’t gather at all, but Lived almost exclusively on seal meat ( which interestingly also protected them from scurvy).

    Surely, there are such serious genetic differences between all of us. Where say today a descendant of such an Inuit living in London, who still has a natural advantage of an ability to live in a severe cold climate surely is also likely to have also a genetic predilection and thus even a real NEED to ‘gather ye rosebuds while ye may’ in times of food abundance? As Cornelius’s quibbles rightly pointed out

  • Keith:

    You're right that the Vikings refused to adapt to climate change: they also apparently refused to stop sending much of their surplus back to Europe in return for religious artifacts, which didn't help.

    I'm not willing at this point to speculate on racial/cultural metabolic differences, other than the “thrifty gene” hypothesis seems to have been largely abandoned.  If anything, blacks in America have a higher rate of obesity and diabetes than whites despite a more recent African origin, which pokes a hole in the idea that Paleolithic seasonality drives obesity in some races more than others.


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  • PrimalNut

    Hi guys,

    this is my first time here. Been reading all day long on this site, very interesting and very insightful!
    I have been on a Primal ‘diet’ for the last 1.5 years and it has made a HUGE difference in my health. I have cured every ailment I had. From degenerative disc disease to life long sinus infections, life long suffering from constipation and extremely hard stools, brittle, prooly growing hair, nails that peeled backwards, misterious skin rashes that would come and go, at some point crippling rheumatoid arthritis in my ankles, feet, wrist and hands and slow steady weight gain even though I’d starve myself and consumed little calories (doh lol).
    I have been following the MDA recommendations of the Primal Blueprint for the past 1.5 years but something was still off. MDA suggests to make vegetables the main bulk of a meal.
    I just switched to an almost 100% carnivorous diet and finally got rid of my bloated belly! Yay.
    The only addiction I can’t seem to shake is my RAW goat milk consumption. Perhaps ditching the darn vegetables and eating more fat will allow me to reduce the amount of raw milk I consume.

    Thx for this site and information

  • PrimalNut:

    It sounds like you've overcome a raft of problems…feel free to link this comment on the “wakeup call” thread.

    I wouldn't stress too hard about the raw goat's milk: try coming off it for a while and see if it improves your health or body composition.  If not, then stick with it!



  • Jean

    I learned a lot while reading this article. Thank you so much for your willingness to compile useful data for those of us who fight carb/food addiction. A million times – thanks!


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  • John

    What is the glycemic index for wine, beer and alcohol? I realise that this will vary greatly between varietals, distillers, brands, etc, but just curious and I haven’t seen anything on this topic.

  • John:

    Ethyl alcohol doesn't have a glycemic index, because only foods containing glucose can elevate blood glucose!  And the point of alcoholic fermentation is for the yeast to convert the sugar and starch into alcohol, so usually there isn't much glucose left.

    Beer contains some residual glucose.  Wine contains very little (with the exception of sweet/dessert wines like Riesling, port, etc.) because most of the sugar has been fermented into alcohol.  And distilled liquors contain basically zero.


  • Lourdes

    I am curious about the relationship between eating disorders and sugar addiction. The model for explaining alcohol an drug addiction, where the brain gets its reward mechanism highjacked by the drug, does not seem to apply to eating disorders (specially compulsive overeaters). Following AA other fellowships like Overeater Anonymous work with the model of abstinence, in this case, abstinence from sugar and white flower. Obviously unlike alcoholic or drug addicts the eating disordered person has to eat. Maybe is a combination between compulsive behaviors and some sort of overreaction to the high of sugar, however I don´t seem to find any literature that explains this connection in a clear way, as it is has been explained when it comes to drugs, alcohol or even OCD.

  • [...] This link and this link were helpful in understanding some of the blood sugar/gluten issues: [...]

  • Kratoklastes

    Firs,t let me make clear that I’m not a ‘shill’ for Big Bread (or Big Wheat, or Big Agra): I am of the view that wheat is to be avoided to the extent possible – the ‘complex’ carbs in it aren’t complex once they hit the mouth; the protein in it is both hostile to human gut lining AND addictive (the gluteorphins and gliadorphins); and WGA (wheat germ agglutenin) – the lectin in wheat – is an endocrine disaster.

    OK… that said:

    I wish people would stop using GI – it’s the equivalent of using BMI (which is an idiotic portmanteau statistic that is meaningless the moment anybody does any resistance training whatsoever).

    The GI of white bread is higher than that of Skittles (and of table sugar), however white bread only contains 51g of carbohydrate per 100g whereas Skittles contain 91g/100g – and furthermore, the fact that the carbs in Skittles are 50% fructose brings into play al lthe bad things about fructose (in the absence of VitC and fibre) that folks like Gary Taubes and Robert Lustig have made clear.

    GI is based on a ‘dose’ of the relevant food that contains 50g of carbohydrate: the fact that bread is 51/91sts as carb-dense as SKittles, means that a serve of bread 91/51sts the size of the equivalent-GI serve of Skittles.

    Glycemic LOAD for a specific serve size is a far more relevant measure. That’s the GI of the food, multiplied by the carbs per unit weight of the food, times the weight of the serve.

    Srsly… get yourself a blood glucose meter, and measure your blood glucose at 20-min intervals after eating a serve of bread and a serve of skittles: there is NO COMPARISON.

    Bread is still REALLY bad for you though: check out the YouTube vids that detail how the well-meaning developement of high-yield semi-dwarf strains of wheat b yBorlaug in the 950s has had disastros consequences for humans. Modern wheat is almost the epitome of a ‘designer diabesogenic’ – AND it’s addictive.

    And who the hell eats Skittles anyhow? Anybody who lets their kid have them is committing child abuse (almost as much as people who religiously-indoctrinate their kids).

  • Kratoklastes

    Oh, one more thing… the post’s about bread (i.e., wheat) addiction, and there’s no mention whatsoever of gliadorphins (the metabolic products of gluten and gliadin)?


    Snark aside: if you give folks Narcan (naloxone) and tell them to chow down on wheaty products, they eat on average 400cal less than control. That’s why naltrexone (oral Narcan) is now approved for use as a weight loss aid.

  • Lourdes:

    Apparently I missed your comment: sorry about that.

    You are correct that the addiction model is not a convincing explanation for overeating: here's a paper that reviews the relevant research and comes to the same conclusion.  

    Nat Rev Neurosci. 2012 Mar 14;13(4):279-86. Obesity and the brain: how convincing is the addiction model? Ziauddeen H, Farooqi IS, Fletcher PC.

    Meanwhile, you might find my series on the science of hunger interesting.  Here's the index.


    Yes, but what is a “serving”?  Does it have anything to do with how much people actually eat at once…or is it a number chosen by the food manufacturer to make the nutrition numbers say what they want them to?  A can of energy drink has two “servings” in it…but since when does anyone drink half the can?

    That's why I find “glycemic load” to be a fudgy number, too: the actual amount of food people will consume depends on its satiating power, not its “serving size”.

    And yes, I'm quite familiar with gliadorphins.  However, this article is very much aimed at the introductory/beginner level…and when you try to tell people that bread is, quite literally, an addictive drug, they tend to shut you out like you're a conspiracy theorist.  (Keep in mind this article was written long before Wheat Belly came out.)


  • [...] Tässä on hyvä artikkeli sokeririippuvuudesta englanniksi. [...]

  • eddie watts

    in the uk you can buy anything with nutrition guidelines based on one serving.
    things like a 200g cake of which a single serving is whatever amounts to 100 calories.
    beyond a joke!

  • eddie:

    It's instructive that we were all much thinner before food even had ingredient labels — let alone calorie counts and serving sizes!


  • Valencia

    This was very insightful! I am not a scientifically inclined person, but everything made sense. I will be making moves to shake my bread addiction, thanks!

  • Valencia:

    Thank you!  For a comprehensive program that will help you improve your health in many more ways, read my guide “Eat Like A Predator, Not Like Prey.”


  • [...] For more on the relationship between carbs and sugars, check out Gnolls.org’s article Mechanisms of Sugar Addiction: Or, Why You’re Addicted To Bread [...]

  • Nina


    I’m a naturally very skinny person at 5’8.5″ 115 lbs (a BMI of 17 which is considered underweight). My body fat measurement has gotten as low as 13% according to a hand-held analyzer. Regardless of what I eat or don’t eat, my weight does not fluctuate more than 4 pounds. I am trying to break my sugar addiction. Can I do that safely with no fat reserves to burn? Do I ‘need’ sugars more than people who have fat stores? If I cut ‘carbs’ and refined sugar from my diet, what can I replace it with to help maintain energy?


  • Nina:

    Even at 13% bodyfat (which is very low for a woman) you've still got well over 50,000 “calories” worth of fat reserves.

    I'm in a similar situation: it's nearly impossible for me to gain weight unless I let myself drink a lot of soda and eat lots of bready junk food, and even then I don't gain much. 

    The biggest advantage for me of breaking my sugar addiction has been that I used to have to eat every three hours or I became cranky and irritable.  Now I usually eat only 1-2 meals per day…it's wonderful not being forced to interrupt what I'm doing to find food every few hours.

    So yes, you can safely break your sugar addiction so long as you're eating enough other food to keep your body happy.  If you find yourself losing too much weight, eat more…and if that doesn't work, start drinking half and half (heavy cream, if you're lactose intolerant) or eating more potatoes and rice.  My general eating strategy, by which I've enabled myself and many others to shake their sugar addiction, is here: Eat Like A Predator.


  • [...] Sugar Addiction: Or Why You Are Addicted To Bread [...]

  • [...] carbs I have been so happy how much better in control my apetite is. I came across this article: http://www.gnolls.org/905/mechanisms…cted-to-bread/ I can't speak to the entirety of everything it is saying but I wanted to point out from me and my [...]


    Paleolithic people had a much lower life expectancy in part caused by deficiencies in diet amongst other things.

    Paleolithic humans included Neanderthal and look what happened to them!

    I’m sure there is some truth in the adage that too many carbs are bad for you but romanticizing a diet based on ancient history is just silly. Why not base it on the millions of years of evolution of apes and that would show that diet should be 100% sugar based. sloppy logic at work here.

    Eat everything in moderation, at a calorie maintenance level, regular exercise, lots of water. Its really not hard.

    Dr C Van Bardelbum

  • DODAH:

    Your sources, whatever they are, are factually incorrect.

    1. Paleolithic people, in all cases for which we have evidence, had longer lifespans than the agriculturalists who followed them.

    2. Their teeth and bones were far more robust, and show no evidence of chronic malnutrition — unlike agriculturalists, whose remains show extensive dental caries (cavities), porotic hyperostosis (from iron-deficiency anemia, i.e. not enough meat), etc.

    More information here: Indian Knoll vs. Hardin Village

    “Why not base it on the millions of years of evolution of apes and that would show that diet should be 100% sugar based.”

    If you're happy being a 60-pound proto-chimpanzee that is limited to living in equatorial forests, and has a tiny 300cc brain incapable of making even the most basic stone tools, go right ahead!  The rest of us left that behind about six million years ago — in favor of an existence requiring both more brainpower and enough meat to support it.  See my series-in-progress “Big Brains Require An Explanation”.

    “Eat everything in moderation, at a calorie maintenance level, regular exercise, lots of water. Its really not hard.”

    If that were true, we wouldn't have an obesity epidemic!  


  • [...] More veggies than a vegetarian. Fill about half of your plate with vegetables at every meal.  They’re loaded with fibre, vitamins and antioxidants  to support healthy digestion and immunity.   Veggies should be your main carbohydrate source, supplemented with a bit of fruit.   Paleo eating is naturally lower-carb than the Standard American Diet, but you should eat to meet your goals and lifestyle.    If you’re very active, underweight, pregnant or nursing, you’ll need more carbohydrates from fruit and starchy veggies like beets, carrots, yams, and squash.   If your goal is fat-loss, a lower-carb diet can be beneficial in boosting your fat-burning metabolism. You may want to include more fruit and starchy veggies at the beginning and taper down your intake as you adjust to the whole food diet, to help avoid cravings and carb-withdrawal. [...]

  • nancy

    What about Gluten-Free Bread? Does it have the same effects as bread and carbs? Thanks!

  • nancy:

    “Gluten-free bread” can contain any number of ingredients, as there's no universally accepted way to make it.  (Typical contents include potato starch, rice flour, tapioca starch, sorghum flour, bean flour, cornstarch, …)

    However, it's all just processed carbohydrate — and while gluten is unhealthy for several other reasons, the usual effect of simply substituting gluten-free junk for the junk you used to eat is a diminution of your savings account.  (Gluten-free bread and cracker substitutes are expensive!)  It's best to substitute the bready junk you used to eat with real food — meat, fish, eggs, vegetables (including root vegetables), some nuts and fruits.  Eat like a predator, not like prey.  

    That being said, gluten-free junk is less bad for us than gluten-based junk, and I do indulge in an occasional treat…but it's still processed “carbohydrate” (sugar).


  • kazy

    I find this article incredibly informative. I do have a questions regarding 2 foods: croissants and chocolate. You said: “When we take fat out of our diet and replace it with ‘carbohydrates’ (sugars), the glycemic index of the food we eat goes up dramatically.” That slabbing butter on your toast lowers the GI. Or if you’re eating some bread but having eggs and sausage, it changes to carb effect on your glucose. So what about croissants which are traditionally baked with tons of butter? Would that put them in a “better” or different category than Ezekiel bread?
    Then there’s chocolate. Sweet, yes, but I’ve heard dark chocolate on occasion is not bad.
    My last comment is you said: “blacks in America have a higher rate of obesity and diabetes than whites despite a more recent African origin.” But that has more to do with the cheaper processed foods in this country that is available to them. Not something they would eat living in Africa. Much in the same way Hispanics from Mexico and South America develop high rates of diabetes once the come to the US and indulge in the food supply of our food industry, where they didn’t have any record of diabetes back in their home of origin.

  • kazy:

    Blood sugar spikes and crashes are only one contributor to hunger and weight gain: nutrition is a primary driver, as I've shown in my presentation “Why Are We Hungry?”  (Print articles here.)  So while slathering butter on a croissant does blunt the blood sugar spike (and adds at least a little bit of fat-soluble nutrition), substituting the white flour-based croissant with food that isn't just empty calories will keep you less hungry and produce better results.

    To that end, sprouted bread will indeed be superior to other breads, but even the humble potato will provide superior nutrition — and whole eggs, meat, and vegetables will be even better still. 

    I agree that dark chocolate in moderation isn't a bad thing: the darker it is, the less sugar it contains vs. cocoa butter, antioxidants, and the odd stimulant and euphoric.  My current favorite is the Lindt 90%.

    “But that has more to do with the cheaper processed foods in this country that is available to them. Not something they would eat living in Africa.”

    I agree.  Indigenous populations, whether Native American, Australian Aboriginal, or Pacific Islander, suffer much more from obesity, diabetes, and other “diseases of civilization” upon adopting a diet of processed industrial Western food than Westerners do — whether they adopt the processed industrial diet in their homeland or upon moving to the West. 


  • [...] Mechanisms Of Sugar Addiction: Or, Why You’re Addicted To Bread – this is a fantastic in-depth article about why you feel you “need” to have such a carbohydrate heavy diet. [...]

  • [...] bread, bagels, cereal, biscuits, coffee, even oatmeal or whole wheat bread is broken down into pure sugar at a molecular level.  Pasta is a no no. As well as candy, milk chocolate, and any sugar. Note: If you are strict to [...]

  • [...] Part I: Why You’re Addicted to Bread [...]

  • [...] the fake foods are either loaded with sugar or made out of something your body will turn into sugar the moment it’s digested. Damn, that’s another rant about to happen. I’ll get to [...]

  • Skgr

    The problem I find with this article is that J. Stanton points out something and says it always leads to this. I have never experienced an addiction to whole-wheat (I have to white bread but that is unhealthier) and I know plenty of others who haven’t as well. You say that people gain weight from being addicted to grains? I have never seen anyone addicted to just plain whole-grain bread with nothing on it. A lot of people I know never eat anything whole-grain.
    And heres the thing, I have and my family love white rolls. But I wouldn’t eat them plain. I would only eat more than 1 if they are buttered up. I’d say fats are more addictive than complex carbohydrates in my experience.
    Also, I have a question. J. Stanton, you say that we should eat more meat and eat it with every meal. Why should I eat (red (which is what you recommend)) meat if my stomach and guts feel bad. Why is our digestive system more like an herbivore’s than a carnivore’s? For example, human teeth aren’t nearly as sharp as a carnivore’s. I’m also pretty sure our stomach acid is much much weaker than a carnivore’s. Our digestive tract is also much longer than a carnivore or even an omnivore that is mostly carnivoristic.

  • Skgr:

    I don’t content that a high-carb diet always causes metabolic inflexibility — that’s clearly not the case, and a combination of other factors Including genetic susceptibility) must also occur.

    Also, I would be careful about generalizing your and your family’s experience to the rest of the world: I’ve received many communications from people who find carbohydrate of any type addictive, regardless of taste.

    Finally, our guts are NOT more like an herbivore’s than a carnivore’s: our stomach acid is just as strong as a carnivore’s, and our digestive tract is NOT “much longer than a carnivore’s.” (Further discussion, including links to scientific literature, here.) Nor do we have a rumen or a cecum, necessary to extract significant energy from vegetation (the rumen and cecum are places where bacteria ferment vegetation into SCFAs.) And we don’t need huge teeth, as we’ve been using sharp rocks for over 3 million years.


  • Skgr

    J. Stanton said


    I don’t content that a high-carb diet always causes metabolic inflexibility — that’s clearly not the case, and a combination of other factors Including genetic susceptibility) must also occur.

    Also, I would be careful about generalizing your and your family’s experience to the rest of the world: I’ve received many communications from people who find carbohydrate of any type addictive, regardless of taste.

    Finally, our guts are NOT more like an herbivore’s than a carnivore’s: our stomach acid is just as strong as a carnivore’s, and our digestive tract is NOT “much longer than a carnivore’s.” (Further discussion, including links to scientific literature, here.) Nor do we have a rumen or a cecum, necessary to extract significant energy from vegetation (the rumen and cecum are places where bacteria ferment vegetation into SCFAs.) And we don’t need huge teeth, as we’ve been using sharp rocks for over 3 million years.


    First off, thank you for pointing out all those inaccuracies. I do have a few more to ask you about but first, a question. Do you believe that humans are primarily carnivorous (about 75% animal based foods and 25% plant based) or omnivores that eat about equal amounts of animal and plant materials. (Please note, I’m not asking this based off of mass but off of caloric energy).

    Doesn’t our saliva contain amylase, an enzyme that breaks down amylose (a complex carbohydrate)? It would make sense if humans were 50/50 omnivores but not if we were primarily carnivorous. Also, why do we have the ability to move our jaw left and right (presumably to grind up plant matter) if we are primarily carnivorous? Do you think that the paleo diet is suitable for all modern humans?

    This is off topic though but why do (not all) vegetarians and vegans report success with their diet in the long term? I understand that vegans can “cheat” with supplements but what about lacto-ovo vegetarians that don’t supplement any nutrients?

  • Skgr

    Also, I noticed in this article you say bread=skittles. Skittles are almost purely sugar with no nutritional value. Bread on the other hand, has many different vitamins and fiber. If you are going by glycemic index, yeah, they’re the same, but, using the analogy “Bread=Skittles” makes it seem like they are equivalent to each other in nutrients when they’re not.

  • Wilbert

    Good article. I’m experiencing some of these issues as well..

  • Skgr

    J. Stanton said

    Finally, our guts are NOT more like an herbivore’s than a carnivore’s: our stomach acid is just as strong as a carnivore’s, and our digestive tract is NOT “much longer than a carnivore’s.” (Further discussion, including links to scientific literature, here.) Nor do we have a rumen or a cecum, necessary to extract significant energy from vegetation (the rumen and cecum are places where bacteria ferment vegetation into SCFAs.) And we don’t need huge teeth, as we’ve been using sharp rocks for over 3 million years.


    Due to recent information I have found, I no longer agree with two of these points.

    About the length of GI tract compared to body length: When we are talking about body LENGTH (shoulders to hips) we have to remember not to measure human height. If we compared our GI tract to height it would indeed be 3.2 to 5.2x the height of a human. If we compare our GI tract to body length it would be about the same ratio as an herbivore’s. So our GI tract is much longer than a carnivore’s, and it is about the same length (in proportion of course) as a herbivore’s is to its body length.

    Not all herbivores need a rumen and cecum. A rumen and cecum are needed for when plant material with loads of cellulose are eaten. (Leaves, stems, grasses.) Other herbivores only need a single chambered stomach. These herbivores eat (Fruit, nuts, seeds, some leaves (i.e vegetables that provide fiber in the form of cellulose) tubers, mushrooms, et cetera).

    I believe that humans evolved to eat whatever is available. Some Paleolithic humans ate more meat (such as the Inuit) while others ate a significant amount of plant matter (can’t remember the names of the people that ate like this but I believe they lived in South America, Africa, and Asia). That’s why humans can find success in multiple diets from Paleo, to Vegetarianism, and more rarely, Veganism.

  • […] analogy is straight out of one of my most popular articles (“Mechanisms of Sugar Addiction: Or, Why You’re Addicted To Bread”), published way back in 2010, and which still gets tens of thousands of page views every […]

  • Skgr

    @J. Stanton
    Just wondering if I’ll get a reply soon. I’m looking forward to discussing this topic with you.

  • […] While they may contain certain nutrients, the anti-nutrients in whole grains actually bind with these nutrients and prevent their absorption. Also, all carbohydrates, whether simple or complex, are broken down into simple sugars in your body. So while you may think you’re getting all sorts of nutrients from your whole grain bagel, all you’re really getting is a sugar rush (source). […]

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