I came across this article:
So, what does cause obesity?
Not grains - Okinawan eat grains and happily living till 100 years old. Many traditional cultures supplement grains. Asians (Koreans and Japanese) eat white rice and they have the lowest obesity rates among other countries.http://www.nationmaster.com/graph/hea_obe-health-obesity
Gluten? Originally, Samoans had very little gluten, yet their obesity rates were high even before gluten consumption. Samoan starch: either breadfruit, taro root, or green bananas. Italians and French indulge in gluten, yet the weight problem has been creeping up on them very slowly, not like in the U.S.
Processed foods? We all know at least one or more individuals who indulge in processed foods (at least till age of 20) and never get fat. So there is a protective mechanism. Also, white flower and white sugar can be considered processed food, but many cultures use it. Spaghetti in Italy is not whole grain. So are baguettes in France.
SAD? Again, we know some examples when people are not overweight even on SAD - I know at least five people like that, even in their late 40s. Why is UK getting fat? SUKD? What about Mexico?
Sugar? Nobody can live only on sugar - I do not know any diets where people would consume only sugar. Interestingly, fruitarians are not overweight by any standards.
Calories? But what makes some people to crave for more junk food?
However, I know a bunch of kids who became obese at the age of 4 or 5 on a relatively healthy diet. Genes? I wonder if there are any twin studies where one twin would be obese, and another one is slim.
EDITED - I am very interested WHY U.S. and Mexico? Why not some other country? GMO sounds like a possible cause. Could it be about chemical additives? Why Mexico? Traditionally, Mexican food is healthy. Is it just a food culture? Very puzzling to me. Also, I have heard that they have reversed an obesity trend in Austria, but I forgot the details.
I would posit that, for most obese people, the underlying problem is diseased and dead mitochondria due to a combination of poor nutrition and a diet that raises inflammatory markers. If the TCA cycle is damaged or cannot run optimally, the fatty acids that make up the energy currency of the body cannot be metabolized, thus promoting storage in adipose tissue. This then explains (at least at bird's eye view) why people who are obese tend to stay the same weight over long periods, since that amount of fatty tissue is what is necessary to get the leptin/adinopectin/resistin/whatever hormone levels up to the point where the remaining mitos are producing just enough energy to run the body.
The only evidence I have for this, really, is the high incidence of keratosis pilaris in obese people, and the findings of dead blobs of tissue that used to be mitochondria in the cells of T2DM patients. But it's so far a better fit for the data than anything else I have seen.
Singling out individual foods or components of food like grains and sugar as the sole cause of obesity only proves these foods are not the sole cause of obesity. The root cause of obesity is multifactorial and those foods may contribute to the pathology of excess weight gain, especially when combined, refined, fried in seed oil and given artificial flavor and MSG for taste.
The cause of obesity is surely a complicated question for which there are lot of contributing answers.
What causes obesity? The answer is very straight forward, despite what overthinkers and Taubes-ites might say - eating too much of anything causes weight gain. Continuing to do that much of the time causes obesity.
Why do people eat too much food generally, and why so much food of poor quality specifically? The list of reasons is huge!
I think Food Reward and convenience play an important role - all the cheap, convenient foods that one will eat even when they are not really that hungry or continue to eat past what is needed to satisfy hunger.
I think the modern snacking mentality also makes this worse. Daycares, schools, and after-school programs insist that kids need several snacks a day. It is always cheap convenient crap they know the kids will eat even if they aren’t really hungry.
I guess I would rephrase the question this way: who causes obesity--and why? Who would most benefit from a population that is fat, sickly, out of condition and/or with heart disease, diabetes, and utterly dependent on drugs for its survival?
Could there be some people who stand to benefit from such a state of affairs? We could follow the money, and make a list--I bet it wouldn't take long to see some significant associations. As in any observational study, association may not equal causation. But it sure might imply it--and suggest the need for further research.
EDIT: The comment from "thhq" caused me to reflect further, and I decided instead of being coy I'd edit my response to explicitly reflect what I was implying.
It's way too long--DO NOT READ!!!!
Exactly What Causes Obesity: A half-baked, sophomoric manifesto I probably should have written when...well, when I was a sophomore. In high school.
The shift of over-eating and overweight from deviant to normal is a sociological problem. A nation full of skinny people did not one day decide, "It's now okay to eat too much and get fat, after all we won the war!"
The normalizing of over-eating and overweight occurred as more people became over-eaters and overweight--just the same way every other human behavior is normalized. The problems leading to our obesity situation were well underway by the time it stopped being okay to make fun of fat people.
And still these things aren't fully normalized. No one wants to be on camera, shoveling in two Big Macs, large fries, and a super-sized coke. Like our recreational drug use, we do a lot of our gluttonous food consumption behind closed doors. No one ever sees how much we eat--or what we eat. They just see more and more of us getting bigger and bigger, and that makes it more normal.
No one thing causes obesity. And no one thing turns individual obesity into a system-wide situation affecting half the population. The obesity problem is the natural result of a vicious cycle that, while perhaps not implemented purposely in the beginning, is now fueled--perhaps purposefully--by money.
The USDA ignores science (going all the way back to the 60's) and continues to recommend an unhealthful diet composed of foods directly refined from the products of federal farm subsidies (our taxes). And we all know what kind of "food" is made from these products. One can hardly use these products as recommended and not become obese. These foods are like automobiles and guns: they are among the few products that, when used for their intended purposes, kill people (in predictable numbers, year by year).
The government adopts new actuarial tables that suddenly categorize many more Americans as "obese," people who were once just "overweight." With their new diagnosis, these people are eligible for new, and more, medical interventions, especially drugs. Statins are prescribed for people who have no signs of CVD. Statins are prescribed for women over the age of 60--a group for which there is no evidence they help, and good evidence they harm. All of this gets the medical/pharmaceutical industry a sweet piece of the action, and you better believe they use it to lobby congress for more. I don't know if the pharmaceutical industry lobbied congress on those actuarial tables or not, but would it surprise you if it did?
Just an annoyingly lefty, half-baked theory here from me: I speculate that a population that is fat and sick with diabetes, heart disease, and cancer will tend to discharge its civic duties at diminishing rates. As we become obsessed with our illnesses (while continuing our consumption), bed ridden and bedraggled by an interminable medley of maladies, we will withdraw from public participation and become more and more attached to our technology, which will mollify our suffering. We, the electorate, whipped for so long by artificially low food and energy costs, will allow politicians the luxury of ignoring us, so long as things stay the same. Corporations (and unions, if any are left, but who am I kidding?) will be in charge. Making people stupid and sick, and persuading them to participate in their own subjugation, is a good first step for implementing control. This technique (hegemony) has been pondered endlessly in fiction, and demonstrated in real life countless times in the world's history of colonialism--long before technology, mega-corporations, and huge world markets were part of the picture.
Now add to all that crap all the many, myriad factors I can't even remember to include in my argument, and then start thinking about feedback loops and vicious cycles. Probability and inevitability.
It seems to me obesity (and all its associated problems) is about the only possible outcome to this system.
To stop obesity, this system must be interrupted somewhere. I am very cynical, so I predict the interruption will come only in the form of the dynamic duo of 1) skyrocketing energy costs, and 2) global climate change. I'm not sure which will happen fastest, or if they will dance slowly together for awhile, acting as force multipliers upon each other, but they are on the way sooner or later. The later they arrive, the fatter and sicker we'll all be. So that's the downside to putting it off. But a faster arrival means horror for all of us. So basically we're screwed either way.
However, we're not necessarily screwed forever. Barring catastrophic depopulation, we'll adapt, perhaps:
Once it's cheaper to grow food locally than to pump it full of fertilizer, pesticide, and ship it across the oceans, that's what we'll start doing. We'll be ripping out Big Box Store parking lots and turning them into fields of sweet potatoes.
We'll sell all our food at local farmer's markets that will dot the landscape the way liquor stores and pharmacies do today, because it's cheaper and easier to sell your food to the people who live within a few blocks of the farm.
When we can't afford gas for our cars (or coal for our electric cars), we'll live closer to where we work (perhaps on that farm), and bike and walk more.
When we can't afford heating fuel, we'll shiver more, and start living in smaller, denser communities with more people.
And we'll finally get skinny again because there just won't be enough of anything to get fat.
I can't decide whether this is dystopia or eutopia. Probably dystopia, on account of the roving bands of cannibals and people stealing your shoes in the winter and guns and zombies. But who knows.
So, that's what I think is the cause of obesity.
I think malnutrition is the biggest reason caused by:
poor food quality (cheap calories devoid of nutrition: cereal, bread, etc.). People starving for nutrition stuff their faces with this stuff and just store up the empty calories while they remain hungry.
digestive problems, allergies, celiac disease etc.
the rise of and media bias of vegetarianism and likewise, the idea that animal products are unhealthy, the increase consumption of lean meats, low fat dairy, etc.
The fact the fast food is the most wholesome food many American's eat on a regular basis (animal products) and as such is very satisfying and rewarding, is also hyper caloric and inflammatory.
The rejection of the proposed answers is misleading, not only because obesity is multifactorial, as Mscott answered, but because it usually takes a long time for obesity to develop. Populations that move to a Western society often do not start to show signs of the diseases of civilization for a decade.
So just because so-and-so has eaten such-and-such all his life, and is still slim at 25, doesn't mean s/he's not going start "unexpectedly" gaining weight at 30. This happens all the time.
And don't forget genetics and epigenetics as extremely important factors.
Its a combination of how processed food affects the body, and how we have demonized and shamed fat in this society. The earlier one goes "on a diet" to lose weight, the larger they will be when they grow up. Women who restricted calories during pregnancy have larger children.
There are almost ZERO fat people who have never been on a diet. It is one of those chicken and egg things, once you think you are even the slightest bit fat, you begin to restrict calories (and usually fat), and you may "lose weight," but you damage your metabolism in the process, and typically gain back more than you lost.
The entire argument over "obesity" is what is causing the issue. We have completely disregarded "health" as the end point goal. Developing better habits that lead to a modest (6 pound) weight loss creates an entirely more healthy person than a person who restricts calories, does chronic cardio, and loses a lot of weight without changing a lot of their health habits.
As seen in almost all "health based diets," removal of processed foods, excess carbohydrates and grains, sugars, and increasing the quality of ones food leads to healthier habits, regardless of weight loss. Which is why people feel better doing Paleo/Primal/Vegan etc.
In my opinion, if you want to boil it down to one simplistic answer, it is the dominance of processed, industrially produced foods in most people's diets. They embody and contain most of the bad qualities that everyone else has mentioned. Not to mention that they are developed by researchers whose goal is to make people eat more than they should. What chance does a person who is genetically predisposed to overeating have against that? To paraphrase Marla Daniels (The Wire), the only way to not lose is to not play the game.
I don't particularly think Taubes has the whole story (or even a significant part of it) with his insulin hypothesis, but his books are extremely important in getting people to think about why something happens, not just how it happens. You can say all you want that obesity is a self control issue, but that's just moralizing about something that's actually biological. Why are so many people unable to control themselves? That's a much more interesting question with an answer that has nothing to do with "They're lazy" or "They're just weak people".
This question is backwards. Instead of asking what causes obesity, maybe we should ask:
What causes a person to maintain a healthy weight level?
Focusing on what causes obesity only results in a list of things you should not do. It tells you nothing about what you should do.
Isn't that the bottom line with paleo--figuring out what you should do?