Monday, August 17, 2015

The obesity epidemics: another problem we don't know how to solve

A suburban market near Florence, Italy, a few days ago. This market is frequented only by local residents and it provides good evidence that the Italians, on the average, are not so fat. Most people you see walking there are in reasonably good shape and I tried hard to find someone truly obese, but I didn't see a single one.  It turns out that, indeed, Italy is less affected by obesity than most (although not all) countries of the Western World. But things are rapidly changing; Mediterranean diet notwithstanding, even in Italy people are more and more gaining weight and becoming obese. The obesity epidemic seems to be another one of those problems that keep getting worse and that we just don't know how to solve. 

We all know that the world suffers an obesity epidemic, hitting in particular the rich countries of the West. But what exactly makes people fat? You could say that it is because they eat too much and exercise too little and that would be, obviously, true. But should fat people be demonized because they can't control their appetite? Being overweight, and, in particular, being obese, brings all sorts of health problems; being also told that it is your fault just adds further misery to an already painful condition (*). Yet, this is a common attitude (See DeShazo et. al.). But consider that a whole scientific field has been developed with the specific purpose of creating food so tasty that people can't stop eating it. And we have a whole industry, the food industry, dedicated to making people eat more, and another, the medical industry, trying to make them eat less. A no win situation, if ever there was one.

There is more to say about the damage done by the modern, hypertechnological food industry. Food is not only a question of how many calories it contains, but also of the nutrients it contains. And there is a reason why we often use the term "junk food"; it is because this food contains plenty of calories, but few nutrients (see also this post of mine). So, it may be that people try to compensate for the lack of nutrients by eating more food; another likely reason for the obesity epidemic (see, e.g.  Swinburn et al.). Obese people are actually malnourished (see, e.g. Hyman).

But there may be more to this story if we consider the situation from a "systemic" viewpoint. Human beings are complex systems and complex systems are known to react in a non-linear manner to external forces. So, facing an obese person, if you are thinking in terms of systems, you won't just say "this person eats too much". Rather, you would ask, "what could have unbalanced the metabolic homeostasis of this person?"

To illustrate this point, let me compare the obesity epidemics to climate change (that we could call a "high temperature epidemic"). The Earth's atmosphere is a typical complex system that reacts in a strongly non linear manner to external perturbations (called, usually, "forcings"). The main forcing causing global warming is the increase in the concentration of the greenhouse gas carbon dioxide, CO2. It is not the only forcing agent, but surely the most important one in unbalancing the atmospheric homeostasis.

Note how all it takes is a small increase in CO2 concentration (little more than a hundred parts per million) to generate a major change in the atmospheric temperatures. It is a point that many people find difficult to understand; not unexpectedly because we are not used to think in systemic terms. But even a small change in the complex atmospheric system can generate a cascade of reinforcing feedbacks that create the disaster we call "climate change." That's the way complex systems work.

Now, could it be that something similar is taking place with the obesity epidemic? Could there be a single agent, or, anyway, a main one, that triggers a cascade of reinforcing metabolic feedbacks that turn normal human beings into land whales?

It can't be excluded, but identifying such a substance, if it exists, is a major - nearly impossible - task. A recent review by Simmons et al. reports a table of 23 putative obesogen substances, chemicals that go from heavy metals to saturated fat, including pesticides, hormones and more. And then the same authors report a table of 38 more possible obesogen additives, but never tested in this sense. A grand total of 61 possible additives that could make you fat; and I am sure that there are many more not listed in the paper.

The sheer number of possible culprits makes one's head spin.  But, in a sense, that can be seen also as promising. What if one of these chemicals plays the role of CO2 in the atmosphere? That is, could one of them be the main trigger of obesity? It would be great if we could point to a specific substance and say: "Look! This is the stuff that makes people obese! Stop putting it into the food we eat!" And, from then on, we would see no more land whales in shopping malls.

Unfortunately, things are not so simple. As I said, the human metabolic system is much more complex than the climate system and, therefore, it is hard to identify such a substance, assuming it exists. The best that can be done is to test the possible obesogens one by one, but what if their effects are reinforced by feedbacks created by their combination? To return to the climate example, by examining the climate system, we could conclude that water vapor is one of the causes of global warming, because it is a greenhouse gas and it is abundant in the atmosphere. But, no, the increase of water vapor concentration is not the cause of global warming, it is an effect of it. We can say that because we know the climate system much better than the human metabolic system.

Then, even if we could identify one or more substances that play a major role in triggering obesity, it may be impossible to remove them from food. Stuff such as heavy metals are just all around us; we have been creating or extracting them over centuries of industrial activity. There is no way to remove them completely from the ecosystem.

And, finally, even if we manage to have scientific proof that a specific substance is the main cause of obesity, we would likely see the food industry gearing up for a major denial campaign. It is easy to imagine politicians stating, "Look, I am not a scientist, but I believe that there is no proof that bis-tetraphenil-dyazin-watchamacallit causes obesity." and then you would hear in the news, "Fatgate: food scientists confess they have faked the obesity data in order to keep their research grants!"  And so on.....

In the end, it seems that the problem with obesity is the same we have with other gigantic problems we face: climate change, the food supply and many others. Often, we are not smart enough to understand what causes them and, even if we do, we are, unfortunately, smart enough that we can stop all attempts to solve them. It seems that we are creating a world so complex that it is becoming impossible for us to manage it.

Let me conclude, however, with a note of optimism (of a sort). Obesity has the advantage over climate change that people can experiment with it by themselves. So, a lot of different diets are being tried, from Vegan to Paleo, and everything in between. With all this experimenting going on, eventually we'll learn something about what makes people fat and how to avoid it. This is, after all, the way the universe manages complex systems: it just discards what doesn't work; it is called natural selection. It would be nice if we could apply the same strategy to climate change; too bad that we have just one planet.

(*) The author of this post has a body mass index (BMI) of 26.2, and that puts him on the lower side of overweight. 

h/t Roberto Rondoni


  1. An interesting and thought-provoking analogy.

  2. Some years ago I switched to a paleo diet and my health improved a lot and especially relevant for this post: I am no longer hungry all the time. I really wonder how many of the health problems we assign to overweight are actually health problems from chronic hunger and dieting.

    To me paleo is more a generator of hypothesis than an exact diet or lifestyle. Given the enormous rise of chronic decease it seems warranted to ascribe a large part of that to the modern lifestyle. If people would live like in the old days, they might have other deceases and accidents, but modern chronic deceases, including obesity, would likely be a lot less. Some people are able to handle this modern lifestyle, others are not adapted to it. How they are not adapted to it is likely different for every individual. That may make it hard to find obesogen X. There are likely many.

    That is why I like your suggestion to experiment. And blogging at variable variability, I wonder whether the variability you create by experimenting is in itself already a good thing. In the past, when the peas in the garden were ready for harvest, you would eat peas until you could not see them anymore. Even if you eat the same total of peas well spread over the entire year now, that may have a different effect on the ecosystem in your stomach. Just like the variability of the weather (for example, how often it freezes (palms trees), how long the droughts are (cactus), how long the ground is not completely wet to suppress the competition (willow)) is important for the kind of ecosystem you see outside.

    For me the main problem seems to have been grains (gluten). That also shows how complicated the problem can be because people ate grains without problems a century ago. Thus there seems to be some interaction. Some people suggest emulsifiers. Might also be more hygiene and less mucus to protect the intestines. Who knows, for now the placebo of no grains works better than the placebo of healthy whole wheat bread.

    1. Yes, Paleo does wonders for me, too, but it is a little difficult for me to follow it in the real world (and especially in Italy). So, I settled to no grains, it seems to work well enough - even though it seems I can't really break the BMI barrier!

    2. When I eat outside, I only watch out for grains. When I cook myself I do a bit more.

      While my hunger went away when eating paleo, like you I also did not get much thinner. Just being able to eat what your appetite indicates is heavenly (not to forget the health improvements).

      Because I did not notice any health effects with dairy, I have kept eating that. However, now I am doing an experiment of removing it for a longer time and it looks like my weight is finally going down, but just a few pound up to now, hard to say it that is real and especially whether it is causal.

  3. I see a very closed relation between these 2 problem apparently without solution, in fact both are tight linked to each other by the same negative energetic source actually specifically called “ignorance”, that’s unfortunately a vicious circles reproducing itself, generating greediness, greediness is generating corruption and corruption can only generate back again ignorance, like in a vortex each of those 3 elements are fueling each other.
    Therefore there a magic word that can solve not only those 2 problem but any problem related to the human impact on this planet and that is “Education” simply and only that.

  4. There once was a rule for dinner party conversation: total abstinence from any discussion of religion, sex or politics. Today it should include diets. Or maybe diets are the new religions: may I be spared from vegans, glutinophobes, kosherholics, etc ad nauseam. My wife and I, our kids and their spouses, have resolved this quandary by almost eliminating dinner parties. (Another reason is that hardly anybody else hosts them these days.)

    One of the finest formal dinner parties we ever hosted included several priests in clerical garb. Yes we discussed religion, sex and politics. Plus Global Warming, education and art. It was a fine group of people. Interestingly, one person was obese, maybe three were overweight. Most were well up in years. Politically, folks were all over the map.

    The BMI is not for those on a salt-free diet. My BMI of 28½ says I am overweight. Physicians tell me otherwise. I have big bones. I cannot float in fresh water, even if I take a huge breath I will sink. When I was a teenager I would freak people out by taking a deep breath and sinking to the bottom of the pool and lie on my back, playing dead. (I can still do so, but I refrain.) My late father, who was overweight-for-real, had a deceptively low BMI — he had small bones. At the beach, he would take a book, float on his back just beyond the surf… and read. This also freaked people out.

    The few people who invite my kids (they and their spouses are 50-somethings) and us to formal dinners are, interestingly, almost all trim. And omnivores. Maybe formal dinners are the secret for staying slim!

    1. I wish I could say the same for my BMI, David, but my wife points at my belly and says, "Ugo, you are fat!" I think she is right, unfortunately.....

    2. I fear I understated or misstated my point.

      When I was a kid, my parents and we kids typically were all at the table simultaneously for breakfast and supper. It was the same for my parents when they were kids. The table was never silent; the meals were generally long; the conversations were vigorous, passionate and long. (Decades later, when I ate alone quite regularly, I gained weight that I found hard to shed. I suspect I was overeating; also, I would have more alcohol with my suppers.) The conversations forced us all to eat more slowly. (My Dad’s problem was because of his beliefs. He believed that what he ate while nobody was looking would never make him fat.) Also, for supper, we kids were not only supposed to wash up, we were also supposed to change into cleaner clothes.

      The general infirmities of advancing age keep my wife and me from being as physically active as in days of yore, but fortunately our appetites have decreased. When she eats alone, she typically eats less than when she eats with me. With me, no such luck. (I hope she outlives me, for several more reasons.)

      The formal dinner is, I feel, a “High Mass” equivalent of the “Low Mass” family dinner: a dressed-up version of essentially the same thing.

      When we dress better, we behave better. In conversation, we are likelier to make sure brain is engaged before putting mouth in gear. And likelier to listen. And to think. I have read that the brain consumes large amounts of energy.

      The big advantage of making a big deal about “dinner” (or other meals) is that it is more fun, more enjoyable.

      And here is the big analogy to Climate. Just as we do not need 2000 food calories to have a good meal, we do not need high quantities of energy to lead an enjoyable life and be a benefit to our families, our friends and to the World. Whoever envies us doing so benefits us by outdoing us.

      All in all, life is to short to drink plonk, smoke bum tobacco, eat junk food, making up for low quality with high quantity.

    3. In Italy, many people try to keep the old habit of having dinner together. Maybe they succeed better than in the US, so far, but I am afraid that if we try to organize a formal dinner here, today, everyone at the table will be looking at their cell phones much more than engaging in conversation.

  5. To make matters worse, we are not only an overly complex system of liquids, hormones, neurotransmitters, cell types & c., but with an equally complex system of thoughts, beliefs, Pawlowian reactions, customs on top of it, and all that embedded into a social system of communications of all types, that can as well run out of control or lock in in some weird state in different ways.
    Concerning diets i prefer a healthy eat-it-all-diet.
    My way of staying (more or less) within boundaries is computer addiction, when i simply don't bother eating - you wouldn't call that very healthy. (& some moderate jogging).
    What can you do?
    I disagree with the education proposition above. The reason is, that eating is governed by a only half consious process, concerning appetite, thirst, stress level, customs & c.
    The climate - bodyweight - analogy is striking in one more point: the power balance of people gaining weight may be tilted by only a small amount. Plus 10 kg fat over 5 years is more or less 90 Mcal. Total burn is 3300 Mcal. Which gives 2,7 % power imbalance. Seems easily to be achieved with some sensor or process in the appetite feedback loop out of whack.
    (somehow the preview function here is broken.... ??)

    1. Dear Dlen,
      quite interesting your opinion, I can undestand and accept your disagreement about education specially if you are a person over weight, in all cases you may surely agree with me that if we will not undestand and control our consious processes we will never have any chance to get out of this jam.

  6. Ciao Professor,

    There seems to be another common thread between climate change and obesity, and it relates back to your Ferragosto posting (which I really enjoyed) — the intersection of corporate profits and our inability to solve problems.

    With the 1% getting rich off both climate change and obesity, we will never be able to even experiment with solutions (beyond our own bodies and perhaps as small communities). For example, it would be obvious to prohibit junk food advertising targeted at small children — but it will never happen. The Junk Food Industrial Complex is every bit as powerful as the fossil fuel interests (or guns in the US for that matter), and I don’t see them going away. So any attempt at experimenting is a threat to corporate profits.

    Having lived in both Italy and the US, the differences between the two food systems is shocking, from what is stocked in the markets, to the number of chain restaurants, to the number of food ads on television. Americans going obese is making a lot of people a lot of money.

    1. Oh, yes, we are very smart at making sure that problems cannot be solved!

  7. I think there is another point in common. It is meat. Both as a cause of obesity and climate change . This makes it particularly appropriate comparison .
    Embrace who raised you .

    1. Eating less meat than the average person sounds like a good idea. Especially because then you can afford to eat good quality from animals that had a good life.

      However, is there better evidence for the relationship between meat and obesity than empirical studies of the quality of the China Study? Which is a book that looks a lot like a very long WUWT post. It does not even consider the question whether a Western lifestyle in general may cause obesity and meat consumption is just a proxy or one aspect of that. A decent study should at least distinguish between real meat and all the processed junk with meat in it.

  8. It must be said that animal protein, in general, especially if consumed more than our stone-age metabolism can handle, is it surely bad for us, causing many diseases, further more the fact that mass production animals, or most of them if not all, are fed with estrogens, antibiotics and other chemicals, that makes a great opportunity for chemicals and pharmaceuticals industry.
    Beside the above reasons, we should reduce meat in our diet also because animal production is responsible for a great share of green house gas and fresh water consumption, both for about 1/3?.... maybe someone knows better.

  9. There's been a steady decline in blue collar vs. white collar jobs in the western world. In blue collars jobs, of course, physical work is done.

    I don't know about europe, but here in the U.S. over the past 40 years there's been an explosion in real estate prices. With that has been has, *perhaps*, been a corresponding decrease in the real money cost of food. That could be a factor.

  10. There are so many endocrine disruptors that they are virtually unavoidable and there is research suggesting that they change our genetics and thus a disposition to obesity can be passed on to the unborn. If I remember correctly all that DDT they sprayed back in the day is one of the first ones. Imagine the cocktail effect spread over multiple generations of ever more chemically exposed people combined with eating evermore hyper caloric, mad scientist food and less sunshine and physical activity. Better living through chemistry?

  11. I certainly do NOT think that it is "the fault" of obese people if they are obese or have become obese. And finding a good collective solution to the problem which clearly involves a wide range of cultural, social, policy, genetic and other factors is, as is typical of complex problems, quite difficult. But I do think that ultimately the solution at a personal level for most cases is quite simple: eat less and better and exercise more and keep it up no matter what others around you think, say or do. Easier said than done but it often DOES work. Naturally it would help if all sorts of policies, propaganda and silly and self destructive cultural habits also changed. But if one is fat and it is starting to affect one's health and energy and etc. can one really wait for those near impossible things to change to receive some helpful support? Even for those who don't believe in God I think they would to well to believe at least in this instance that "God helps those who help themselves". Maybe after they have lost 30 kilos or even more they also will become "believers".

  12. nicole.lascurain@healthline.comMay 20, 2016 at 8:34 AM

    Hi Ugo,

    First off, I came across your site and wanted to say thanks for providing a great health resource to the community.

    I thought you would enjoy this interactive infographic which details the dangers fast food has on the body. It will be helpful to persuade anyone trying to cut out fast food out of their diet to visually understand the toll it can take on your body:

    Naturally, I’d be delighted if you share this embeddable graphic on , or share on social. Either way, keep up the great work Ugo!

    All the best,

    Nicole Lascurain [ Assistant Marketing Manager ]
    t: 415-281-3100 f: 415-281-3199

    Healthline Media, Inc.
    660 Third Street, San Francisco, CA 94107 – @healthline – @HealthlineAdLab

    About Us:



Ugo Bardi is a member of the Club of Rome and the author of "Extracted: how the quest for mineral resources is plundering the Planet" (Chelsea Green 2014)