Home > Uncategorized > We don’t know why we’re all so fat

We don’t know why we’re all so fat

March 14, 2017

One of the most ridiculous aspects of the “blame the individual” approach to obesity is the overall trend of fatness throughout the country and the world over the past few decades.



The rates of obesity have skyrocketed and we simply don’t know why. Here are a few reasons that are consistently trotted out:

  1. People have become lazy. (Actually this one’s easy. In fact we’re getting more exercise and it doesn’t seem to help. And for that matter, exercise doesn’t make you lose weight.)
  2. We’re eating too much fast food.
  3. We’re drinking too much soda and generally eating too much sugar.
  4. We’re watching too much TV/ playing too many video games.
  5. There are too many food options constantly surrounding us.
  6.  Our portion sizes are too big.
  7. We’re just eating too much of everything. In some sense this is a tautology. The question is why.
  8. Glyphosates in our grains are making us fat.
  9. Our internal stomach biomes are messed up and make us fat.
  10. Bad genetics make us fat. This one’s easy too, since our gene pool hasn’t changed that much recently.
  11. Dieting itself makes us fat.

So, there are tons of reasons, and I’m sure I missed some. The tricky thing is, all of them sound plausible, and none of them are likely the single answer. Likely it’s a combination of a bunch of them.

But the truth is, we don’t know. And people hate not knowing stuff, so they pretend they know. That’s not helpful. We need to be scientists and try testing out hypotheses.

The biggest problem with testing the above hypotheses is that many of them are hard to avoid environmental factors of modern life. You can take the soda machine away from a high school but then the kids will just buy soda at the nearby corner store.

Until we’ve figured it out, I’d like us to admit I don’t know why we’re all so fat. And I’d like us to stop blaming individuals, especially children.

Categories: Uncategorized
  1. Matt
    March 14, 2017 at 10:33 am

    This is the most interesting question to me, and the fact that these graphs don’t go back very far in time is one of the more interesting parts: are McDonalds and Coca-Cola really more popular now than they were in 1987 or 1997? Is food that much more abundant? My intuition is “not really”, but I could be wrong about that. If we saw the spike in the immediate post war years when food was becoming much more processed and abundant than it had been before, I could see these arguments as being a lot more compelling.

    One other thought: data I’ve seen suggest that even within countries, these trends are different in different places, whether that’s states, metro areas, rural / urban, or whatever. Looking at proposed causes through that lense may be the least bad way to assess some of these conjectures, but I don’t know of any work that’s convincing based on such comparisons, would love to be pointed at some if they exist.


    • March 14, 2017 at 10:35 am
    • Auros
      March 14, 2017 at 7:38 pm

      I wonder what the inflection point around 1980 could be… Something about the Reagan deregulatory era? Putting unhealthier food into school lunchrooms?

      Though that doesn’t make sense of the way that animals are along for the ride. So maybe something to do with deregulation of the chemical or pharma industries, or perhaps even the invention of a few key products (plastic variants, pesticides, pharmaceuticals that reach the water table due to poor disposal practices or because metabolites aren’t adequately processed out in wastewater treatment)…


  2. Josh
    March 14, 2017 at 1:03 pm

    The whole idea of talking about “the reason” or “the cause” of anything complex degrades discussion. There are always a number of contributing factors and each of us seem to be free to focus on whichever one suits our purpose.

    For instance, what is “the reason” Trump won? Everyone points to whatever they want to justify their position. Trump won because he was a good campaigner, because the people liked what he was saying, because his supporters are racist, because of upset with elites, because of fake news, because of Clinton’s terrible campaign, because the Bernie supporters didn’t support Clinton strongly enough, because of the Electoral College, because of voter suppression, because of James Comey, because of Russian hacking, because of economic malaise, because…

    .. take your pick (or come up with your own) and conclude whatever you want. They all have some basis because reality is complicated.

    I’m not saying that some things aren’t more important that others. But, the idea that we can focus on one thing to the exclusion of everything else and each of us can pick which “reason” we want to focus on leads to people talking past each other and forming self-reinforcing groups — even without any completely false information.


    • March 14, 2017 at 2:02 pm

      I disagree. Trump won for a number of reasons, and it’s probably unimportant to know exactly how much each thing contributed, but the real issue there is that it’s already over and we need to deal with it. So in that sense we’d be wasting time just talking about why.

      But with obesity, if we found (for example) that glyphosate was a huge part of the story, then we could stop using it in agriculture. That’s an important question on an ongoing problem.

      In other words, we should care about “why” here because we’d like to intervene.

      Liked by 1 person

      • Josh
        March 20, 2017 at 11:21 pm

        I didn’t mean to suggest that it wasn’t important to think about causes — just not to think/talk about them too simplistically. I agree it would be good to understand the important factors.


    • March 14, 2017 at 2:04 pm

      This is exactly the reason I think it’s a terrible idea to “admit we don’t know until we’ve figured it out.” There is a public health crises, and we know a lot about a lot of the contributing factors. Sugar is a major factor (probably the most significant). High GI carbs are a major factor once someone has developed significant insulin resistance. Our gut microbiota plays a role. Etc.

      It’s quite disingenuous and unethical to pretend like we know nothing until we have 100% certainty of 100% of the contributing factors. I’d argue that the attitude of “let’s just admit we don’t understand this” is a causal factor of those graphs going up and not the other way around (that the graphs going up means we don’t know).

      Liked by 1 person

      • Guest2
        March 14, 2017 at 2:57 pm

        Yeah, but Cathy is right to point out that for any individual, we do not know enough to address obesity on a personal basis — we don’t know metabolism, starvation effects are poorly understood, and gut microbiota “plays a role” doesn’t help the local physician very much. So, no — we do NOT know how to personalize what we do know on an scientific level. Too bad. Who needs the science if it is irrelevant at the personal level?


  3. March 14, 2017 at 1:34 pm

    100% agreement with Josh; it’s silly to talk about “the reason” for obesity, when individual variables & genetics differ so widely. There are LOTS of problems/questions like this out in the real world, where certainty does not apply, and the synergies at work are almost incalculable… which is why, again, I’d be wary of any statistical study pointing to one answer.


  4. ed
    March 14, 2017 at 1:54 pm

    Because we like food (for the obvious reasons of genes/evolution), and food or, more precisely, calories have gotten much cheaper than they used to be.

    Liked by 1 person

  5. Johan
    March 14, 2017 at 2:00 pm

    Your missing an entry from your list (admittedly a recent one): leptin-resistance. https://www.youtube.com/watch?v=WMdSHNnRbEs

    But what really makes the problem weird is this: The obesity epidemic is not limited to humans.


  6. Nutt Eugene
    March 14, 2017 at 3:46 pm

    I believe some urges and their mechanisms have not been fully explored, i.e. hunger, excepting for banding or bulimics some of whom loose interest in eating, waste away and die. There are different shades of this, in genetics it was DNA that brought it out of the doldrums, Masters & Johnson did a lot to “normalize” sexuality.

    So I’m waiting for that landmark study that unravels all those threads yielding a method keeping you trim just as germ theory led to a hygiene cycle countering contagious diseases. Note, a lot of people and places don’t know that germs cause disease, plagued with diahrea, polio and tuberculosis.


  7. March 14, 2017 at 3:46 pm

    One more for the list: a virus did it. https://www.wired.com/2016/12/mysterious-virus-cause-obesity/


  8. rjh
    March 14, 2017 at 4:07 pm

    I guess it helps that I completely ignore the usual sources, because I work with clinicians and epidemiologists. It’s fair to say that there are hints in the data, but no clear simple causal answers. One hint comes from analysis of India, where the changes are less from westernization and much more from changes in the nature of work. They’ve got a huge obesity change temporally related to the shift from brutal manual labor to machine assisted labor and office labor. It’s large enough that they’ve re-defined the basic minimum calorie level for food assistance. People need about 20% fewer calories to maintain a steady weight.

    I’m not surprised. The internal system relationships for basic type 2 diabetes show over a dozen different organ systems interacting by means of almost two dozen hormones and nutrients, with various timescales for reactions. That’s a complex system that is way beyond the simple explanations available using the popular press method of “A causes B”.

    Obesity will be more complex.


  9. March 14, 2017 at 7:31 pm

    The crazy thing is that _animals_ are getting fatter too. And not just pets.


    It’s possible that our plastic effluvia have pervasively polluted our water with endocrine-disruptive chemicals. :-/


    • Auros
      March 14, 2017 at 7:34 pm

      Oh, I see somebody else linked to a story about this issue too…


      • March 15, 2017 at 7:12 am

        Thanks though, it’s super interesting.


        • Ben
          March 17, 2017 at 9:37 am

          Combine the animal observations with Kevin’s post and link to the Wired article on a possible virus connection- see above. And, hasn’t ag been trying to make by various means ask the animals we eat bigger? Is that in some manner transferring to us?


  10. Laura
    March 14, 2017 at 10:38 pm

    I totally agree that we have no clue. But there is more to be said for the genetic aspect than I would have previously thought. The research into epigenetics and gene expression and passing it on to your progeny is really interesting. It is plausible that having multiple generations with prolific amounts of food have affected our genes to be more susceptible to gaining weight.


  11. AHG
    March 15, 2017 at 4:01 am

    Increased caloric consumption explains everything. I’m sure there are proximal things to point to like increased soda consumption or portion sizes, but CICO underlies it all.


    Liked by 1 person

    • March 15, 2017 at 7:09 am

      As I said, tautological. Doesn’t explain why everyone’s eating more.


      • ed
        March 15, 2017 at 2:53 pm

        Because they can.


      • AHG
        March 15, 2017 at 9:43 pm

        I disagree it is tautological. As you state in many of your proposed explanations, people are offering non-caloric explanations. Establishing this base fact helps shed light on which explanations are valid and which are not. I also disagree with your usage of the term “tautological” as a simple matter of logic. Saying increased caloric consumption caused the increase in obesity does not contain “the increase in obesity caused the increase in caloric consumption”.

        Liked by 1 person

        • March 15, 2017 at 9:55 pm

          I agree, I shouldn’t have said tautological. What I thought you said was that people were getting fat because they were eating more calories than they were using. That is, in fact, what fat reserves represent, so that explanation would have be tautological. So, I misread your message. Apologies.

          It’s of course possible that we might be eating the same number of calories but using less, which would also make us fatter. So it’s not obvious we’re eating more calories per se, although chances are we are.

          The question can be rephrased as: why are people, since 1970, eating more calories than they are using? What about our homeostatic systems around energy use has changed?


  12. March 15, 2017 at 4:55 am

    1. Weight gains post 1970’s can be correlated to Nixon’s agriculture policy under Earl Buntz. The policy paid farmers to farm rather than to idle fields, which was a reaction to inflation in the 1970’s, to lower the cost of food. Previous farm policy, under FDR, payed farms to idle fields, to counter deflation in the 1930’s, when food prices were to low.


    ” . . . [Butz] abolished a program that paid corn farmers to not plant all their land.”

    “Butz argued that the corn subsidy had dramatically reduced the cost of food for all Americans by improving the efficiency of farming techniques. By artificially increasing demand for food, food production became more efficient and drove down the cost of food for everyone.”


    This correlates to the graph referenced by Ms. O’ Neil:

    2. The cause of obesity is known: carbohydrates.

    Carbohydrates are a fat storage molecule.
    Biochemically carbohydrates are not essential, unlike fats and proteins, as the human body can synthesize carbohydrates.


    This is basic biochemistry, and can be verified by minimal google searches.

    Wendy Pogozelski, a Chemistry professor at the State University of New York, did a TED talk on the problem of carbohydrates:

    Peter Atta, MD.also did a Ted Talk on this subject:

    Gary Tubes wrote a book on this topic, “Why We Get Fat and What to Do About It”


    • March 15, 2017 at 7:14 am

      Dude, anything can be verified with google searches. Also, I’m giving a TED talk, doesn’t mean I’m right about everything.

      Which isn’t to say I am not paying attention to sugar and corn as a culprit. But I don’t think it’s in any sense a slam dunk.

      Liked by 1 person

    • March 15, 2017 at 2:34 pm

      This policy also reduced the price of food in the U.S. so very few people in the U.S. are now starving, many fewer than were from the 1930s-1960s.


    • Auros
      March 18, 2017 at 2:52 am

      Can corn subsidies explain why marmosets are getting fatter?

      There are plenty of things one can do with corn other than eat it. It can be processed into a liquid fuel, or cat litter, or various plastics.

      And you can’t really posit the price mechanism — calories are cheaper therefore we eat more — as driving things. Rich people (for whom food has always been a negligible portion of their budget) have gotten fatter too. If it were as simple as “people who can afford to tend to overindulge in sweets, and now we have more people who can afford to,” that wouldn’t be the case.


    • Auros
      March 18, 2017 at 2:57 am

      Honestly, given that we know that stress and sleeplessness can disrupt metabolism, leading to diabetes and obesity; and we know that virtually everyone up and down the income scale now sleeps less, works more, and feels less secure about their ability to hold onto their social position; I’d suggest that “economic insecurity” could be as big a driver as the food landscape. Socialism for health!

      Liked by 1 person

  13. A. Nony Mouse
    March 15, 2017 at 1:56 pm

    Something has changed and it’s clearly not just bad individual choices.

    My guess, and just a guess, is a deadly combination of too much of the wrong kind of food, and a reduction of physical activity in our mechanized world.


  14. Lou
    March 17, 2017 at 11:59 am

    The worldwide graphs of obesity (and diabetes) since the 70s, when the cheap, synthesized high fructose corn syrup was introduced, track the increasing consumption of this malformed industrial poison.


  15. Bob A.
    March 17, 2017 at 10:57 pm

    Its not increased calories:
    I refer to an excellent analysis by: (hope you dont mind)

    Robert H. Lustig, MD, UCSF Professor of Pediatrics in the Division of Endocrinology, explores the damage caused by sugary foods. He argues that fructose (too much) and fiber (not enough) appear to be cornerstones of the obesity epidemic through their effects on insulin. Series: UCSF Mini Medical School for the Public [7/2009] [Health and Medicine]

    Alot of American foods include all sorts of corn-based products. Even citric acid is derived from corn, and well HFCS is in everything.

    Sugar: the Bitter Truth (lecture to UCal students)

    Liked by 1 person

    • Lou
      March 20, 2017 at 11:49 pm

      HFCS is indeed ubiquitous — some ignorant beekeepers are winter-feeding it to their hives, but such industrial poison does not help their pesticide-compromised bees.
      IMHO, the distinction between ordinary corn syrup and it’s cheap, synthesized imitation is the negative chirality side-effect derived from synthesis : 50% malformed, unnatural industrial poison.


  16. Bob A.
    March 26, 2017 at 10:18 pm

    Hi again, Ive meaning to add this other stuff. Gut flora I’ve read, make up half our bodies digestive system and are largely responsible for the conversion of foods into useful products.

    I’ve also be hearing about the impact of gut flora on ones health and metabolism:
    Its been on and off on CBC Radio over the last few years.

    *Gut bacteria may be key to fighting obesity
    Fat mice get lean after intestinal bacteria transplants from humans (and vice-versa)



  17. Izzie
    April 9, 2017 at 12:45 am

    But we kinda do… Everything you mentioned above has to do with either behaviour, genetics, environment or a combination of them (with perhaps the exception of the biome, which is a fascinating in itself).

    If getting fat is a side effect of insulin resistance, and we understand pretty well how exercises, food (mostly carbs and protein), choices, timing and environment impacts insulin dynamics (and we do since the 1950’s, see Gary Taubes, IHMC and others) – is this still a mystery?


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