September 8, 2013

Obesity in Germany: The fault-line divides the nation again

The civilizational fault-line that cuts Germany in half has more on-the-ground effects than what type of folk culture the people adopt, or what their religious history has been. It turns out that the stereotype of "fat Germans" or "fat German tourists" is another example of outsiders observing only one half of "Germans," and applying what they see to all of "Germany."

Hilly/mountain country is more suitable for (agro-)pastoralism, while the vast lowland plains can support large-scale agriculture. If the local diet reflects the local subsistence mode, then we'd expect folks in the west and south to rely more on animal products than they do in the north and east, where we would expect grains and other plant crops to play a larger role.

Obesity, and other symptoms of metabolic syndrome, is primarily caused by an overly high amount of carbohydrates in the diet. Digestible carbs are burned as glucose, which is metabolized by insulin. And insulin is the only hormone that locks fat in the fat cells, rather than release fat into the blood to be burned for energy. So, a long-term reliance on a high-carb diet will tend to lead to the symptoms of metabolic syndrome -- not only obesity, but also diabetes, hypertension, insulin resistance, etc.

Metabolic syndrome is a "disease of civilization," a consequence of agriculture.

Now let's look at a map of the prevalence of "overweight" and "obese" people across the various German states (sources cited here). The top one shows the percent of the state that has a BMI between 25 and 30, the bottom one a BMI over 30. White means low, light blue means intermediate, and dark blue means high compared to the national average.

Looks like a pretty good fit with a topographical map, especially the bottom one showing obesity. The obesity rates for whites in America reflect the topography in a similar way (see this map), with folks in the hilly/mountain parts being slimmer than the "corn-fed" people from the Plains and Mid-west or deep South.

Combining both categories gives the following ranking from heaviest to slimmest. (Here is a map showing which states are where).

64.4% - Mecklenburg-Vorpommern
64.3% - Saxony-Anhalt
63.5% - Thuringia
62.8% - Brandenburg
61.2% - Lower Saxony
60.7% - Rhineland-Palatinate
59.9% - Saxony
59.3% - Bavaria
59.2% - North Rhine-Westphalia
58.8% - Schleswig-Holstein
57.8% - Hesse
56.9% - Baden-Württemberg

(I omitted the city-states of Berlin, Hamburg, and Bremen because they're urban centers and not representative of the general area around them. Like how D.C. often gets left out of state comparisons in America. I omitted Saarland for the same reason -- in area and population, it's like the three city-states.)

The only major exception to the north/east being the fattest is Schleswig-Holstein. Saxony is not as fat as the rest of the eastern states, but the article says that the obesity rates do not tell the whole story about Saxony. In the nation as a whole, half of obese people also have diabetes, whereas 3/4 of the obese in Saxony do. So for overall metabolic disorders, it is probably not unlike the other eastern states.

The differences are not huge -- not even 10 percentage points between the fattest and slimmest states. Turning percentages into z-scores, we find a 0.2 standard-deviation gap between the top and bottom states.

But those small differences in the average can lead to dramatic differences in the tails of the distribution. For example, the really tubby Germans we see on beaches are probably from the north/east. And lithe people like supermodels are probably going to come from the west/south. Indeed, both Claudia Schiffer and Heidi Klum hail from North Rhine-Westphalia. (In fairness, Tatjana Patitz comes from Hamburg.)

Tacitus said that the Germanic tribes ate mostly meat and milk (being nomadic pastoralists), and that their bodies were large and strong compared to the wheat-eating Romans. In fact, the barbarians truly were taller than the civilized agriculturalists. This was probably due in large part to diet, because among the Romans themselves, their heights showed a high-low-high pattern over time that reflected their reliance on pastoralism-agriculture-pastoralism. Man does not live by bread alone.

Once the Germanic groups who occupied the lowland plains began to use the land more for sedentary agriculture than for grazing their livestock, that set them off on a different evolutionary path. That is only within the last 2000 years, but natural selection can work fast when the pressure is strong. And being thrown into a strange new subsistence mode would definitely qualify.

I wonder how much Viking influence remains in Holstein, whether genetic or cultural. They are pretty slim, and they're world-famous for their local breed of dairy cattle, the Holstein Friesian. So they might not have gotten pulled toward the adaptation to agriculture as strongly as the rest of their northern neighbors, and stayed a bit closer to the nomadic pastoralist roots of the Vikings. But that's just a hunch.

10 comments:

  1. Have you read any of Stephan Guyenet's writings on obesity at his blog, Whole Health Source?

    He's convinced me that the carbohydrate/insulin theory of obesity is at best an oversimplification, and that a starch-based diet, particularly one based on tubers, is not necessarily a recipe for metabolic dysfunction.

    There are a number of cultures where people eat starch-based diets while still remaining lean, such as the Kitavans and traditional East Asian cultures. Only when they began adopting westernized diets, which have higher levels of fat, which have a higher percentage of calories from fat, Furthermore, it's well established that obesity can be induced in mice by feeding them on the "cafeteria diet," which is higher in fat than standard lab chow.

    This doesn't mean that fat, as such, causes obesity. Guyenet's claim is that the problem is food reward&emdash;the tendency of certain foods to promote overeating through stimulation of the brain's reward center. Most such foods (ice cream, potato chips, french fries, cookies, etc.) are high in both fat and carbohydrates, which is one reason why low-carbohydrate diets promote weight loss, but also why traditional starch-based diets promote weight loss as well. Both eliminate the highly rewarding mixtures of fat and carbohydrate that promote overeating.

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  2. West Virginia is the state most closely associated with hilly culture in the U.S, but it's also the most morbidly obese.

    Wikipedia has a page listing U.S states by elevation, but there's four different possible measures. Which do you think correlates best with obesity?

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  3. "West Virginia is the state most closely associated with hilly culture in the U.S, but it's also the most morbidly obese."

    That's because everybody but the bottom has left West Virginia.

    You have to look at the Mountain states instead. ("Rocky Mountain boys.")

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  4. There are a number of cultures where people eat starch-based diets while still remaining lean, such as the Kitavans and traditional East Asian cultures."

    Though remember that obesity is just one symptom of the broader Metabolic Syndrome. I remember reading that Japan is the 2nd most diabetic country on Earth.

    "Only when they began adopting westernized diets, which have higher levels of fat,"

    Well sure, you need to eat fat in order to store it. So you need both carbs and fat in the diet to become obese. But thin starch-eaters are creating an illusion because of the other symptoms of Metabolic Syndrome (diabetes, insulin resistance, etc.).

    And most folks couldn't stand to eat only starchy food -- it has to have fat to provide any taste to it.

    East Asians have a blunted sense of taste, disgust, pleasure, or something, that allows them to not mind bland fat-free food. But that's unusual. You definitely could not "teach" that to other people around the world. "Here's a nice baked potato, but you can't put any butter, olive oil, or sour cream on it."

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  5. the blondest9/8/13, 4:44 PM

    Actually a lot of starch-based foods are low in carbs. Brown rice for example has low carb and has more nutrients than white rice. Paleodiet nerds of course do not know this. They believe that high starch diet in general is bad based on dumb ideas about human history abd food. Most people in the recent past use to eat grains that have more fiber and less carbs than today. The fact that our paleo-ancestors did not grains is not the problem with a high starch diet. It is the fact that most of the grains that people eat today are not like grains of the past. East Asians and Westerners do not eat much brown rice anymore. This is in part due to the fact that grains with high carbs are higher yields and last longers. Brown rice for example spoils faster than white rice. Most countries like Japan and China would have to import more grain if they switched to brown rice.

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  6. The effects of starchy agricultural diets showed up very quickly and were nasty and pervasive. See Paleopathology at the Origins of Agriculture, the main scholarly edited volume on the topic.

    Also see the post (and cite) on Roman vs. barbarian heights. Romans shrunk when they gave up pastoralism in favor of agrarian farming during the Empire, then regained their height once the Empire crumbled and they could no longer sustain massive-scale farming, hence turning back to smaller-scale herding of animals.

    I don't doubt that modern industrial efficiency-maximizing, cost-minimizing carbs are even worse than what destroyed Roman health.

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  7. The theory strikes me as very Lamarkian. Lowland Germans in an earlier period ate lots of starch, which is known to cause obesity. Fair enough. But how exactly does this translate into a genetic predisposition to obesity? Did they somehow acquire a hereditary tendency to obesity?

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  8. Not a genetic predisposition. They continue to eat more starch / less animal fat compared to the southerners. An assumption, because I don't have hard data on differences in macronutrient content across regions, but a fairly straightforward one. I.e., they've been eating more starch for a very long time, and that's unlikely to have changed, let alone reversed sign, very recently.

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  9. The obesity rates for whites in America reflect the topography in a similar way (see this map), with folks in the hilly/mountain parts being slimmer than the "corn-fed" people from the Plains and Mid-west or deep South.

    Although I don't think this quite matches up to the UK, where I think the Scots tend to be slightly more obese and overweight and the rest of the Celtic Fringe are comparable to England, with the mountainous north and western upland regions of England tending to increase England's obesity "score" as well.

    Danes and Scandos are generally rather slender as well, possibly for the same reasons as East Asians (happier with a blander diet with more fish and vegetables and less fat), if to a lesser degree.

    I think statistically, Germans are not particularly obese as Europeans go, although they have many overweight folks. Rather chubby more often than whalelike. Assuming similar standard deviations in obesity between countries (or subregions) might be a bit of a problem.

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  10. I would expect the opposite with the people with the longest history of eating starch to have more genetic adaptation to the modern diet. Unless you did a diet survey I would expect traditional local diets to have much influence on a modern mass consumerism population.

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