• 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.


Fat And Glycemic Index: The Myth Of “Complex Carbohydrates”

(This article is Part III of a series on carbohydrate addiction. Each part stands alone, but I recommend starting with Part I, “Why You’re Addicted To Bread“, as it explains the fundamentals. Part II is here.)

The Mystery of the Flour Tortilla

This article started when I asked a simple question: “Why do flour tortillas have such a low glycemic index?”

The humble flour tortilla tops any list of low glycemic index grain products, with a GI of only 30. Yet whole-wheat bread has a GI of 71! (Source.)

Why is that?

“Complex Carbohydrates”…Not So Complex After All

Most low-fat diet pushers (from Pritikin, to Ornish, to the ADA and US government, to vegan fronts like the PCRM) make a big noise about “complex carbohydrates”. The theory goes like this: Table sugar is made of just two simple sugars, glucose and fructose. That’s bad, because it digests too quickly for our body to use all of it—whereupon the excess is turned into fat, stored as fat, and we’re hungry again. In contrast, the ‘complex carbohydrates’ in whole-grain products are good because they digest more slowly, allowing our body to use all of them. Right?


As described in Part I, whole wheat bread (71) has the same glycemic index as white bread (72), and both of them have a higher GI than white table sugar (62)! This fact alone proves that the theory of “complex carbs” is flawed: our bodies absorb the sugar from that ‘healthy’ whole wheat bread more quickly than…pure table sugar.

Low Glycemic Index: What’s Responsible?

So what’s the real story behind glycemic index? Why do we digest some ‘carbohydrates’ (sugars) so much more slowly than others? And how does a flour tortilla top the list?

Answer: it’s the fat.

  • Mexican flour tortillas have a GI of 30, whereas American whole wheat bread has a GI of 72. Remember, you need plenty of lard (or, at least, grain oil) to make a nice, flat, chewy tortilla.
  • A plain French baguette has a sky-high glycemic index of 95: spread some butter and jam on it, and the GI declines to 65.
  • Cooked white rice has 0.2% fat and a GI of 64; a meal of white boiled rice, grilled hamburger, cheese, and butter has a GI of 24.
  • A Pizza Hut Super Supreme pizza (13.2% fat) has a GI of 30, whereas a Vegetarian Supreme (7.8% fat) has a GI of 49.

This is common sense once we think about it for a minute. As anyone who’s taken a freshman nutrition class can tell you, fat inhibits gastric emptying and slows digestion. For example:

Pierre Thouvenot, C Latge, M-H Laurens, and J-M Antoine. Fat and starch gastric emptying rate in humans: a reproducibility study of a double-isotopic technique. Am J Clin Nutr 1994;59(suppl):781S.

Executive Summary: A high-fat mixture of egg yolks, olive oil, and butter left the stomach over 50% slower than spaghetti…and that doesn’t even count the time taken to digest it in the intestine. (Also note that spaghetti has a glycemic index of 38-61, depending on cooking time—much lower than bread or cereal at 70-80.)

In conclusion, the theory of “complex carbs” is a red herring. The primary driver of glycemic index is fat content. The more fat, the slower the sugars (‘carbohydrates’) are digested, and the lower the glycemic index.

(Yes, it is possible to make lower-GI pure carbohydrates: a wheat ‘bread’ containing 80% intact kernels gets down to a GI of 52…just under a Snickers bar at 55. But wait…80% intact kernels? That’s not bread…that’s a cake of birdseed! I’ve never even seen that sold in a store, let alone watched someone actually try to eat it.)

Conclusion: A Low-Fat Diet Means A High Glycemic Index Diet

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.

This has obvious negative consequences for our health and weight, and I’m going to highlight it, because it’s the key to this article:

High-GI ‘carbohydrates’ (sugars), simple or complex, are digested far more quickly than we can burn them for energy, whereupon our bodies convert them into fat and store them as fat—leaving us hungry, even though we are gaining weight!

Then, we get a transient dopamine rush and subsequent serotonin high before our blood sugar crashes, but that decreases over time as we get fatter—meaning that we are chemically as well as metabolically addicted to sugar (‘carbohydrates’).

Does this situation sound familiar? You’re told to take those ‘unhealthy’ fatty foods out of your diet—and suddenly you’re either hungry and miserable, or you’re gaining weight uncontrollably. Ever wonder why you don’t feel full no matter how many plain bagels, glasses of skim milk, cups of low-fat yogurt, and boxes of fat-free Fig Newtons you eat…yet you still have the compulsion to keep eating?

Even worse, if this vicious cycle of goes on long enough, you become insulin-resistant, and then diabetic. Isn’t this what’s happening to all of America? Our ‘obesity epidemic’ started once we told people to avoid fat at all costs…

…and now you know why. It’s because by removing fat from your diet, you’re turning everything you eat into candy.

Incredible but true fact: a medium Jamba Juice fruit smoothie (‘Berry Lime Sublime’) has substantially more calories (487) than a Quarter Pounder (417)—and a large has almost as many calories (610) as a Double Quarter Pounder (647)!

Which one will leave you feeling like you ate a meal, and which one will leave you still hungry?

...than the Quarter Pounder!

This has more calories...

But Isn’t Fat Bad For You? Science Says “No.”

We’ve been told for decades that fat and cholesterol are bad, and saturated fat will kill you. That is, stated baldly, a lie.

There is no association between saturated fat intake and heart disease, and there is no association between egg intake (the largest source of dietary cholesterol) and heart disease.

Patty W Siri-Tarino, Qi Sun, Frank B Hu, and Ronald M Krauss. Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. Am J Clin Nutr Jan 2010

“A meta-analysis of prospective epidemiologic studies showed that there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD or CVD.
“The pooled relative risk estimates that compared extreme quantiles of saturated fat intake were 1.07 (95% CI: 0.96, 1.19; P = 0.22) for CHD, 0.81 (95% CI: 0.62, 1.05; P = 0.11) for stroke, and 1.00 (95% CI: 0.89, 1.11; P = 0.95) for CVD. Consideration of age, sex, and study quality did not change the results. “

Here’s the layman’s version, from Scientific American:

Carbs Against Cardio: More Evidence that Refined Carbohydrates, not Fats, Threaten the Heart“, Scientific American, May 2010

“…The quintile of women who ate the most easily digestible and readily absorbed carbohydrates—that is, those with the highest glycemic index—were 47 percent more likely to acquire type 2 diabetes than those in the quintile with the lowest average glycemic-index score.” … “women who were overweight and in the quartile that consumed meals with the highest average glycemic load, a metric that incorporates portion size, were 79 percent more likely to develop coronary vascular disease than overweight women in the lowest quartile.”

“The next time you eat a piece of buttered toast, [Ludwig] says, consider that ‘butter is actually the more healthful component.'”

Moving on to eggs:

Public Health Nutr. 2010 Jul 16:1-10. Egg consumption and CHD and stroke mortality: a prospective study of US adults. Scrafford CG, Tran NL, Barraj LM, Mink PJ.

“We did not find a significant positive association between egg consumption and increased risk of mortality from CHD or stroke in the US population. These results corroborate the findings of previous studies.”

So: eat fatty meats, eat eggs, eat avocados. Cook with butter, tallow, and coconut oil, and perhaps some extra-virgin olive oil for taste. And if you absolutely must eat candy in the form of bread, cereal, or potatoes, eat them with plenty of butter, olive oil, cream, and whole milk.

Sounds a lot better than rice cakes and dry toast, doesn’t it?

Live in freedom, live in beauty.


Postscript: if you want to know how we got bamboozled into believing that foods we’ve eaten for millions of years (meat) were bad for us, but industrial products that didn’t even exist until this century (‘vegetable oil‘) were good for us, you can watch Tom Naughton’s entertaining presentation “Big Fat Fiasco”, available here and on DVD here.

(This is Part III. Go back to Part I, Part II.)

“So what do YOU eat?” you ask. Click here for my classic article “Eat Like A Predator”.

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When The Conclusions Don't Match The Data: Even Loren Cordain Whiffs It Sometimes, Because Saturated Fat Is Most Definitely Paleo (Updated)

(Note: This article has been revised, extended, and greatly improved as a result of an error caught by an alert commenter.)

Caution: contains SCIENCE

Origins and evolution of the Western diet: health implications for the 21st century
Loren Cordain, S Boyd Eaton, Anthony Sebastian, Neil Mann, Staffan Lindeberg, Bruce A Watkins, James H O’Keefe and Janette Brand-Miller.
American Journal of Clinical Nutrition, Vol. 81, No. 2, 341-354, February 2005

This paper is basically all you need to know about why paleo diets work, and why they are the most healthy diet possible…

…with one exception. The authors make a giant mistake by regurgitating the “saturated fat is bad” dogma, even though their own data refutes it.

First example: in the subsection “Fatty domestic meats”, they claim that wild game is much leaner than feedlot cattle (this is true)—and then claim it is much lower in SFAs (saturated fatty acids), which is false according to their own data!

Click to zoom. Image ©2005 AJCN.

In Fig. 6, showing seasonal variation in caribou body fat, caribou at their leanest (in April) contain 9% saturated, 8% monounsaturated, and 2% polyunsaturated fats—a fat profile of 47% SFA, 42% MUFA, and 11% PUFA. At their fattest (in October), they contain 33% SFA, 29% MUFA, and 5% PUFA, or a fat profile of 49% SFA, 43% MUFA, and 8% PUFA.

Here are their claims:

“Because subcutaneous and abdominal body fat stores are depleted during most of the year in wild animals, PUFAs and MUFAs ordinarily constitute most of the total carcass fat (11). [False: half the carcass is SFA. 47%/53% and 49%/51% equal 1/2 within the precision of their data set.] MUFAs and PUFAs are the dominant fats in the edible carcass of caribou for all 12 mo of the year, as illustrated in Figure 6 (11, 60-65). [False again: as shown above, there is as much SFA as MUFA and PUFA combined.] Because of the seasonal cyclic depletion of SFAs and enrichment of PUFAs and MUFAs, [What seasonal depletion? 49% to 47% is insignificant, being well within the rounding error of the percentages they use in the table] a year-round dietary intake of high amounts of SFAs would have not been possible for preagricultural hominins preying on wild mammals. [False again! The table of fat content Cordain uses assumes that hunters selected an animal purely at random from the herd, which is nonsensical.]

In other words, every claim in this paragraph is factually false according to the authors’ own data!

Hunters Didn’t Choose Random Animals

My last statement clearly requires justification. Let’s look at hunting strategies used by actual Late Pleistocene caribou hunters, to whom Cordain presumably refers. (Hat tip to Peter at Hyperlipid for the reference.)

Subsistence strategies and economy in the Magdalenian of the Paris Basin.
In: R.N.E. Barton, A.J. Roberts and D.A. Roe, eds., The Late Glacial of Northwest Europe: Human Adaptation and Environmental Change at the End of the Pleistocene, pp. 63-71.
Council for British Archaeology Research Reports 77, London.
(alternate location, easier to read but in two parts: part 1, part 2)

The age distribution is dominated by prime adults, suggesting selection of individuals to be killed. At Le Flageolet although males are present, females appear to be more numerous, which is consistent with individual encounter hunting in the winter, due to their superior nutritional state after the rut.

“[At Pincevent and Verberie,] The toothwear for the one and two year old individuals indicates that the kill took place during the autumn at both sites … The large size of the kill and the season point towards a hunt related to the autumn migration (at least at Verberie).”

“The primary use made of reindeer [note: reindeer = caribou] was, of course, nutritional. The autumn hunts indicated by the dental eruption sequences at Pincevent and Verberie would be designed to exploit the prey in its best condition of the entire year. The summer forage would have fattened up the herd to its maximum annual weight, and even more importantly, to its highest fat content. Both meat and marrow are important for the diets of reindeer hunters. Speth and Spielmann’s arguments (1983) about the desirability of fat in the diet are particularly pertinent for cold climate hunter/gatherers in the winter. The fat in marrow can supply twice as many calories per gram as protein can, and can allow efficient metabolism of the protein from meat. There are no whole bones in the faunal assemblages from Pincevent or Verberie. There are abundant impact fractures, systematically placed to open the medullary cavities for the extraction of marrow.” [Note: marrow is very high in fat.]

This behavior is shared by all other known hunting cultures:

Jack Brink, Northern Plains archeologist, from his masterwork “Imagining Head Smashed In”:

“Fat, not meat, was the food source most sought after by all Plains Aboriginal hunting cultures…”

“Assuming that bigger was better, he [George Carlin] aimed at a massive bull and suffered ridicule and laughter from the rest of his party ‘for having aimed at an old bull, whose flesh was not suitable for food.’

“My people killed three bulls … which served for our dogs.”

Click to zoom. Image ©2005 AJCN.

So it is abundantly clear that not only were the healthiest and fattest animals selected by Paleolithic hunters—the hunters also orchestrated mass kills during the season they were fattest in regions where winter cold made meat preservation practical. Yet this behavior is not reflected in Figure 6, which assumes hunters selected randomly each time by using an average value.

Fortunately Figure 5 shows average fat concentrations for mature bulls, young bulls, and mature females. Using the figure of 25% bodyfat (from a mature bull in October) with the cubic regressions Cordain uses, taken from this figure in this paper, yields…

…90% of calories from fat, not 67% as listed in Fig. 6! So if we choose an animal of the healthiest of the three types in Fig. 5, as caribou hunters clearly did, we get the following percentages:

Month % calories from fat,
Fig. 6 claimed
% calories from fat, calculated from
actual bodyfat in Fig. 5 and cubic regression
Jan* 29% 54%
Feb 25% 48%
Mar 22% 44%
Apr 19% 36%
May 22% 42%
Jun 22% 45%
Jul 28% 54%
Aug 41% 64%
Sep 58% 75%
Oct 67% 90%
Nov* 55% 66%
Dec* 49% 59%
Average 36% 56%

(* Most likely animals eaten in these months were from October mass kills, so these percentages are conservative)

Finally, note that caribou hunters didn’t kill an average animal of each type, either: they selected the fattest…usually females who had not borne a fawn that year, a category not shown in the table. And this further assumes that they never threw away lean muscle meat, or gave it to their dogs, as Plains Indians were well-known to do. So these figures are most likely lower bounds of fat consumption.

Thus, we can easily see that fat provides the majority of calories for caribou hunters, even under pessimistic assumptions.

This argument is reinforced by the fact that humans can only metabolize a limited amount of protein each day…approximately 200-250 grams. But an active hunter burning 4000 calories per day, if eating only the claimed 36% of their calories from fat, would average 1260 calories a day of lean protein—or approximately 360 grams! This is nonsensical.

Finally, I note that caribou hunting is a recent adaptation: Homo sapiens didn’t reach Europe or East Asia at all until perhaps 40,000 years ago. Quoting the original paper again, “Larger mammals generally maintain greater body fat percentages by weight than do smaller animals.” Recall that preagricultural hominins preferentially hunted megafauna: mammoths, mastodons, giant ground sloths, giant tortoises, gomphotheres, chalicotheres, giant hartebeest, giant bison, woolly rhinoceri, and the myriad other megafaunal species that our ancestors drove extinct during the Quaternary period. Even modern American bison (let alone ancestral bison) are many times larger than caribou.

Such animals would have contained a much greater percentage of carcass fat, which would therefore have comprised a much greater percentage of the human diet. Taking caribou as typical representatives of the hunter-gatherer diet is somewhat disingenuous, as humans didn’t even reach the area where caribou lived until perhaps 40,000 years ago. (Compare this to our 2.6 million year history of butchering animal carcasses with stone tools, and the fact that meat-eating most likely dates from before our split with chimpanzees 6-7 million years ago.)

Is Modern Red Meat Higher In Saturated Fat? No.

Now let’s compare the fatty acid profile of…modern feedlot beef.

According to the USDA’s food information database, the fat profile of grain-fed beef is approximately 46% SFA, 50% MUFA, and 4% PUFA.* In other words, grain-fed beef has a slightly lower percentage of saturated fat than wild caribou—and we have disproven another of the authors’ key claims about saturated fat. (“Marbled meat results from excessive triacylglycerol accumulation in muscle interfascicular adipocytes. Such meat has a greatly increased SFA content…” [which we’ve just proven false])

In fact, based on Table 5 of this Cordain paper, the fat of wild game averages approximately 45% SFA (saturated fat).

Finally, the fact remains that hunter-gatherers ate all portions of the animal. Hunters did not trim their steaks—and they ate the fatty parts of the carcass, such as brains and visceral fat, that modern humans throw away! Therefore, the fact that modern muscle meat is fattier is balanced by the fact that we throw away much of the fat which Paleolithic humans consumed with relish.

The rest of the article is indeed correct, including their subsequent conclusions about the PUFA profiles (n-3 vs. n-6) of wild game vs. feedlot beef—but their conclusions about saturated fat are simply a regurgitation of disproved theories which are contradicted by their own data, as well as recently but clearly established science.

Therefore, though it is an excellent paper overall, we can safely discard all its conclusions relating to relative intake of saturated fats.

Live in freedom, live in beauty.


(* I can’t link directly to results in the USDA online database, so I’m forced to link to pages at nutritiondata.self.com, which crawls it. And the composition varies slightly by cut and by individual animal, but is close to those values for the cuts I’ve looked at.)

For far more detail on the subject, you can read this comment.

Postscript: I don’t have time to list all the research showing that saturated fat is, in fact, good for you, because that’s another article by itself—but you can start here:

Am J Clin Nutr 91: 535-546, 2010. Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. Patty W Siri-Tarino, Qi Sun, Frank B Hu and Ronald M Krauss
“A meta-analysis of prospective epidemiologic studies showed that there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD or CVD.”

And here’s the formal refutation of The China Study, the last refuge of the “meat and fat is bad, eat grains and go vegetarian/vegan” dogma since Ancel Keys’ Seven Countries Study was conclusively refuted (most recently by the tremendously entertaining documentary Fat Head) as misleading trash science.

Finally, my purpose is not to trash Dr. Cordain: he’s done a great deal of good over the years, and “Origins and Evolution of the Western Diet” is a solid summary of the issues, one to which I’ve referred people many times. But that particular section (“Fatty domestic meats”) is simply wrong, and I hate to see people scared away from eating paleo because they can’t get game meats or grass-fed beef at their local supermarket—or because they’re still afraid of saturated fat.

(Did you like this article? Click here for more articles tagged “data != conclusions”, or here for more articles tagged “paleo”.)

Why Companies Keep Pay a Secret, and Why You'd Rather Know The Truth

“A new study by researchers at the University of California at Berkeley and Princeton University suggests that if all of our salaries were made known tomorrow, half of us would be made miserable and the other half would be made no happier.”
-Smart Money Magazine, “Why Companies Keep Pay a Secret

The implication is that we’re all better off not knowing the truth.

This, however, is only the employer’s half of the story. This information is indeed of negative value to the organization…but it is of positive value to the workers.

Information, in a free market, causes prices to equalize. However, salaries within an organization are not a free market. The only way to meaningfully increase your salary is by leaving and taking another job, and the only way to meaningfully decrease your salary is by getting fired or laid off.

So there is a free(ish) market in the larger sense of the employment market as a whole, and employees participate in this larger market—while employers would rather restrain them from doing so by withholding information, forcing them to sign non-compete agreements, and so on.

Employers benefit from keeping pay a secret because they can pay some of their employees less than their market value and redirect that profit to themselves. An underpaid employee may quit and get a new job at a better salary, which is indeed a disadvantage to their old employer…but it is an obvious advantage to the employee, who will be much happier at an employer who is not trying to cheat them out of earning their full market value.

In other words, this article is correct in its data, but wrong in its conclusions.

If you’re not convinced, here’s an analogy:

Your Price: $?.??/lb

The article might as well argue that there should be no price tags in supermarkets, that we should each negotiate a price for hamburger with the store the first time we walk in, that we should pay that price (indexed to inflation) for the rest of our lives when shopping with that store—and that none of us should ever be able to find out what anyone else is paying for hamburger.

It should be obvious that such an arrangement benefits the store (who can charge some of their shoppers well over market price) but disadvantages the consumer.

It should also be obvious that while a shopper might be initially dismayed to find out that they were paying substantially more than another shopper under such a system, they would be much happier in the long run to know who was paying what, and to use that information to be able to pay a lower price for hamburger instead of continually wondering whether they were being cheated.

But, of course, the article and study only account for the immediate, short-term effect on the employer.