It isn't controversial to point out that we face serious public health problems: while modern medicine is helping us live longer, more years of our longer lives are spent fatter and sicker. Some of the biggest problems, obviously, are the related illnesses of obesity, diabetes, and heart disease.

Since these problems are ubiquitous, there is no short supply of efforts to solve them. This is a good thing, right? Well, not necessarily. That would partially depend on whether most of these efforts are based on correct principles of health and nutrition. And that is an open question, because there are many very different approaches to health and fitness out there, and many of them conflict. For example, the conventional approach tells us to avoid saturated fats (go easy on the red meats and egg yolks) and seek whole grains (6-11 servings per day, even). But then there are less conventional approaches (but with plenty of credibility) which give almost the opposite advice. For instance, the low-carb approach advocates a diet high in fat and protein. Then there's the paleo approach which tends to embrace fat, while avoiding post-agricultural foods like grains, legumes, and dairy, which are staples of many other diet plans.

I won't get too far into the details of these diets. The point so far is that in order to gauge our current prospects for improving public health, we need to answer two questions: (1) Which approach to health and nutrition is the right approach? and (2) Which approach currently enjoys widespread acceptance? If we get two different answers (that is, if an incorrect approach enjoys widespread acceptance), then we have a problem. But this result would seem unlikely, because once we begin to make any progress regarding (1), that progress should influenc the answer to (2). In other words, if some approach has become more mainstream than the others, that's probably because it's the most correct approach. This is what we should see happen as a result of fair and honest scientific debate: the best ideas will (eventually) emerge victorious from the battlefield of ideas and win widespread acceptance.

But this process may not play out like this if non-scientific intervening forces get involved and influence which approach ends up winning widespread acceptance. The u201Cnon-scientific intervening forceu201D that I have in mind here is, of course, government. The U.S. federal government, in many of its actions, has prematurely taken a non-neutral stance on the scientific debate about what constitutes a healthy and nutritious diet. In doing so, it has helped one approach become entrenched dogma. Once the government got involved, there ceased to be free or fair marketplace of ideas about health and nutrition (and there hasn't been for a very long time). And this is an important reason that the answers to the above questions (1) and (2) might be (and probably are) different. (It is worth mentioning that I am not dismissing the influence of Big Business (Big Ag, Big Pharm, etc.). But I do believe that their influence is ultimately supported by partnerships with the government, as well as policies which benefit them, such as food regulations and intellectual property laws. But these issues are worthy of whole articles (or books!) in themselves.)

The point is that there can't be a fair battle of ideas over health and nutrition when the federal government is essentially using its power and influence to impose one approach from the top-down. Its favored approach, as we all should know, has been the conventional approach which advocates a low-fat, higher-carbohydrate diet. This approach demonizes artery-clogging-saturated-fat, glorifies the almighty heart-healthy-whole-grain, and also recommends low-fat dairy, plenty of fruits and vegetables, and lean meats and fish. The federal government has backed (and imposed) this approach in many ways, some of which follow. First of all, there are the USDA Dietary Guidelines, which currently comes in the form of u201Cmy plate.u201D It also imposes this approach in its school lunch programs. One of the latest schemes is a partnership with Domino's Pizza, which will be providing u201Csmart sliceu201D, a whole-wheat reduced-fat pizza to be served in increasing numbers of public school districts all over the country. And then there are the various taxation and subsidization schemes, dating back to at least the first part of the 20th century. These interventions manipulate food prices (they make grains and grain-fed animal products cheaper) and thus influence the eating and grocery-shopping habits of millions. There is, of course, much more, but my purpose here is not to give a full catalogue of the federal government's influence over what we eat.

The result of all this is that this conventional whole-grain-loving fat-phobic approach is now insulated from the corrective forces inherent in a free and fair marketplace of ideas. If, for instance, Domino's-fed public school children get fatter and more diabetic over the next five years, don't expect an end to the partnership between Domino's and the government. Domino's has much better lobbyists (with much more money) than diabetic children. Nor will it cause the USDA to rethink its Guidelines. Do you think the USDA would ever tell us to eat less of the stuff (grains, corn, soy) grown by the farmers it's supposed to represent? Never. More importantly, making any significant changes in dietary guidelines would amount to the federal government admitting that it is, and has been, wrong. This would be an admission of (at least some) responsibility for the increases in obesity, diabetes, and heart disease (and their resulting deaths) in recent decades. Such an admission will most certainly never happen. So, even if the conventional diet does make us all fatter and sicker (which probably is the case), and even it fails to find any conclusive support in the scientific literature (which actually seems to be the case), it will nonetheless maintain its widespread acceptance as nutritional dogma or u201Cconventional wisdomu201D (which, sadly, is the case).

It is important to point out that the implementation of these policies presupposes a certainty about what constitutes the healthiest and most nutritious diet. This would be ok if some definitive scientific consensus about diet and nutrition pre-dated these policies. But was not the case. Rather, the government interventions in question pre-empted any such scientific consensus in the name of u201Cdoing somethingu201D about heart disease. The biggest offense was perpetrated by the McGovern Senate Select Committee on Nutrition and Human Needs, when it published its u201CDietary Goalsu201D in 1977, advocating a low-fat high-carb diet. This advice soon found support from the National Institutes of Health. (The American Heart Association soon followed, prompting the development of a massive low-fat food industry.)

The problem is that, at this point, the verdict on nutrition was far from in, and many scientists warned that such premature action was unwise and dangerous. Phillip Handler, president of the National Academy of Sciences, raised an important question:

u201CWhat right has the federal government to propose that the American people conduct a vast nutritional experiment, with themselves as subjects, on the strength of so little evidence that it will do them any good?u201D

This may have been an important question for politicians and bureaucrats to consider. But McGovern's defense was that u201Cwe Senators don't have the luxury that a research scientist does of waiting until every last shred of evidence is in.u201D So, here we have a clear admission that the conventional high-carb low-fat approach began with no clear scientific basis. Nonetheless, political support has helped this scientifically unspupported approach to become (and remain) dogma.

As has often been pointed out, the u201CDietary Goalsu201D was a product of overzealous government do-goodery, and this is partially right. I don't doubt that there were plenty of good intentions involved. But it is also worth noting that the McGovern Committee needed its existence renewed every two years. Marshall Matz, a member of that committee, admits that their real concern was with u201Csay[ing] something on this subject [of diet and heart-disease] before we go out of business.u201D That is, if the committee would have erred on the side of caution, it may have lost funding or become expired, causing committee members to lose their own sense of importance. So, what we also see is here is self-interest on the part of these public officials. Many of us with romantic notions about u201Cpublic servantsu201D might doubt that such a thing is possible. But here we see demonstrated the fundamental insight of Public Choice, namely that public officials are human too, and they act on selfish motives and limited knowledge just like the rest of us. But the unfortunate difference between public officials and private individuals is that their bad decisions can effect millions. Anyone who appreciates these basic principles of Public Choice wil not be surprised that a bunch of politicians put millions of Americans' health at risk in order to keep their committee in existence.

I don't mean to give the full history here, as there is much more to the story. (For more of the story, see Gary Taubes' NYT article u201CWhat if it's all been a big fat lie?u201D or part one of his book, Good Calories Bad Calories. Or check out Tom Naughton's funny, yet super-informative, documentary, Fat Head.) The take-home lesson is that the political verdict on nutrition predated any scientific verdict. This means that the origin and basis of conventional nutritional wisdom is not science, but politics.

Meanwhile, many other approaches to health and nutrition are battling obesity and disease with more of a bottom-up approach. This approach involved trying to exert influence by means of blogs, podcasts, books, and plain ol' word of mouth. And what is importantly distinctive of this bottom-up approach is the lack of government intervention. Anyone is free to read and listen to the paleo and low-carb voices out there, and eat according to their prescriptions. But they are also free to ignore those voices completely, and to not eat according to their prescriptions. (This is not so much the case with the conventional approach.)

This means that these alternative approaches to health and nutrition are completely vulnerable to the corrective forces inherent in a free and fair marketplace of ideas (as they should be!). If paleo or low-carb diets were to make people fatter and sicker, or if scientific studies were to emerge condemning these approaches, then word would spread. Those advocating paleo or low-carb would then be put on the defensive, and if they cannot respond to the challenging objections and damning evidence, they and their ideas would soon become marginalized. In the end, the choices of many individuals (i.e. market forces) would make these failed approaches go away, and they would have never been able to cause health problems on a very large scale. And this is how scientific debate and the battle of ideas should work.

Unfortunately, this is not the case for the conventional approach, which will persist as dogma so long as it remains supported by political forces.

Consider two sets of health-conscious parents who care about what their children put in their body, but who subscribe to different approaches to health and nutrition. The first set of parents rejects the paleo and low-carb approaches. If they don't want their kids eating in these ways, all they have to do is not feed them accordingly. And if they subscribe to the conventional approach, their kids are likely to be fed this way by default through little effort of their own, especially if they attend public schools.

But the second set rejects the conventional approach. They now have to worry about the fact that their public-school educated kids will be fed lots of carbohydrates (including grains) but very little fat. And this is not to mention the problems posed by government-influenced doctors (which is looking only to become more of a problem) and the artificially high-prices (and scarcity) of the foods that they would like to feed themselves and their children. For this set of parents, their children's health is a steep uphill battle.

And this second set of parents of a rare breed, indeed. This is because the conventional approach is simply the default. It's what we all learned in school. It's what we see pushed by the government and media. It's what most well-intentioned and trust-worthy figures (parents, teachers, coaches, clergy, etc.) will advise. Giving a non-conventional approach a shot requires some independent thinking and research, but most of all it requires a willingness to swim upstream and a skepticism about what we all u201Cknowu201D is true. This situation might be fine if it were the effect of true scientific debate and a free and fair market place of ideas. But, as we have seen, it isn't. It's the product of the political process and government intervention into our lives.

In short, my main point here is not to argue in favor of one approach over the other (although it should be obvious that I tend to favor the paleo and low-carb approaches over the conventional approach). My main point is that because the government has pre-emptively gotten involved, one approach has become insulated from corrective forces. It is now entrenched, and neither evidence against it, nor the actions of individuals who reject it, are likely to change that. And I'm certainly not suggesting that the government change its policies to support the paleo or low-carb approaches. There is still a lot that is not known about health and nutrition, and so taking any side of the debate is inherently risky. But this risk is unavoidable, as we all have to pick some way to eat. But this risk should be one that individuals take for themselves. It should not be imposed by means of government force and influence, as this is essentially amounts to to an unnecessary and dangerous gamble on the lives and well-being of millions.