U.S. food supply inconsistent with dietary guidance

The U.S. food supply is far out of balance with dietary recommendations. A new study in the Journal of the Academy of Nutrition and Dietetics quantifies the gaps. In brief, the U.S. food supply was quite unhealthy already by the 1970s and has not improved noticeably since then.

The authors -- Paige Miller, Jill Reedy, Sharon Kirkpatrick, and Susan Krebs-Smith -- use a measure more commonly applied to individual survey data, called the Healthy Eating Index. Getting this measure to fit national food supply data from USDA requires a bit of shoe-horning, but nonetheless the results are persuasive about the basic picture. As the video below illustrates, for example, Americans have for decades had all the protein we could possibly need, but the food supply for vegetables falls much short of recommendations.

The video -- from the National Collaborative on Childhood Obesity Research (NCCOR) -- generally thinks of the food supply as "upstream" and food consumers as "downstream." A possible implication is that policies should alter the food supply so that downstream consumers could eat more healthfully. It should be noted that people in the food business, and perhaps most agricultural economists too, give greater weight to consumer preferences for unhealthy food as a key driver of the gap the study describes. Economists may suggest that the food supply would provide plenty of healthy food if that's what consumers actually would buy.

Still, nutrition scientists and agricultural economists have in recent years been doing better than ever at listening to each other's perspectives on these big questions. For example, in an accompanying article, which calls on dietitians to get involved in designing federal policies such as the Farm Bill, Claire Zizza reviews agricultural economics perspectives as well as public health perspectives on how such policies should be evaluated. It all makes a lively conversation.

 

Independent analysis of the Healthy Weight Commitment Foundation trillion calorie pledge

An independent evaluation reported today that the Healthy Weight Commitment Foundation succeeded in removing more than a trillion calories from the U.S. food supply, as originally pledged.

Through this pledge, leading food and beverage manufacturers had promised to reduce total food energy sold by 1 trillion calories, from a 2007 baseline through 2012.

Using Nielsen scanner data from supermarket electronic cash registers and from a random sample of consumer households, Shu Wen Ng, Meghan M. Slining, and Barry M. Popkin estimated calorie trends and reported the results today in the American Journal of Preventive Medicine.

To some extent, the accomplishment simply reflects downward trends in the packaged food and beverage sector, which is losing market share over time -- mostly to the restaurant industry but perhaps partly to healthier food options. In an accompanying editorial in the same journal, Dariush Mozaffarian asks whether the pledge is a "marketing ploy."

As a rule, nutritional targets -- and other quantitative information intended for general audiences -- should be stated in easily explained per-capita terms. Who knows what a trillion calories in aggregate even means?

It reminds me of silly infographics that take a common-sense concept and convert it to some obscure immense quantity. For example, in my in-box this month, I have an infographic from Guiding Stars, which aims to report the amount of running required to burn off the average American's sugar consumption. Sugar is estimated at 3 pounds per week (a sensible way of explaining the quantity), while the amount of running is stated as 2.7 times around the globe over a lifetime (an irrelevant quantity designed merely to appear large to easily-impressed readers).

Today's study by Ng, Slining, and Popkin nicely goes beyond its assessment of the original trillion calorie pledge and also reports the modest but non-negligible resulting calorie changes on a per-capita basis. To the extent that the results reflect improvements in particular categories, such as sugar sweetened beverages, the findings are still reasonably upbeat.

The Healthy Weight Commitment Foundation -- and the companies that made pledges -- will be delighted by today's coverage in major media outlets such as U.S. News and World Report, which states the good news broadly: "Obesity continues to plague the country, but it appears as though food companies are beginning to take strides in helping alleviate the problem."

Dariush Mozaffarian: to address chronic disease, we should focus on food patterns rather than nutrients

In my school's latest Wednesday seminar, the epidemiologist and cardiologist Dariush Mozaffarian methodically builds the scientific case for amending our traditional obsession with total fat (as a culprit in obesity) and saturated fat (as a culprit in heart disease).

Then, from about minute 47:30 to 50:30 in the video, he drops the hammer. Summarizing this large body of research, he argues that federal dietary guidance to address chronic disease should focus on food patterns rather than nutrients. In sharp criticism of the "Go, Slow, Whoa" guidance that still appears on the website of the National Heart, Lung, and Blood Institute, Mozaffarian concludes, "This is insane!."

The speech implies big changes afoot. And I don't just mean for federal dietary guidance. This summer, Mozaffarian took the helm as the fourth dean of my school, the Friedman School of Nutrition Science and Policy at Tufts University.

Dean Dariush Mozaffarian, MD DrPH-Global Dietary Priorities and Policies to Improve Cardiometabolic Health from Tufts Friedman School on Vimeo.

Patent office okays patent for "Diane's Manna"

The federal government last December allowed a patent (U.S. patent 8,609,158) for "Diane's Manna," a supplement that is ...

so potent that it removes or alleviates depression, mood disorders, Attention Disorder symptoms, thought disorder, mental illness, pain, right lip retardation symptoms, physical problems, Lymph Node cancer and many other illness symptoms. 

Yes, that's quite a trick, but there's more:

It is extremely strong or potent and can be made weak to make your little Attention deficit child normal. It is an incredible mood stabilizer and reduces psychosis. Use it for cancer patient and for people with pain issues. It works.

According to the patent, the supplement is "made from distinctly and uniquely combined and processed interchangeable seed and seed derivatives."

The inventor, Diane Elizabeth Brooks of Sandy, Oregon, has an unusual background, as the patent explains:

I am a minister who has prayed my way through this medicine. 

The inventor provides extensive evidence of effectiveness based on her own personal experience.

I have used all of the ingredients listed. These all are used for the claims. Please know that these are continual medicines and are very good if you take them and make sure your body is filled with these before you ever stop or halt using them. 

This drug is to be used by all people who hate going to the Pharmaceutical companies or going to doctors who have a great problem in diagnosing our illnesses. It is for the people to judge. I am very ill. When I get sick, it is imperative to make myself a large dose of this recipe and take a large dose for many days. It causes a mild psychosis in me during this phase. I have to endure that to get to the right dose. I always lower the dose to my needs, but only after I have flooded my body with enough of the medicine to create this continuum. 

The primary examiner at the U.S. Patent and Trademark Office (USPTO) was Michael Meller.

This patent was recognized this week by the Electronic Frontier Foundation as the "Stupid Patent of the Month." I heard about it on BoingBoing. The EFF points out that the patent should have been rejected on any number of grounds, "including enablement, indefiniteness, and utility."

I think awarding such a foolish patent undermines the government's credibility as an authority that can help consumers sort through conflicting evidence on diet and health claims.

Our attention to diets (continued)

Here's another one. This is a Google Trends report of online interest in "sodium" and "gluten", 2004 to the present. High sodium intake in the U.S. population increases the prevalence of high blood pressure and heart disease, which are leading killers in the United States. Yet, this topic is ovewhelmed by the growing American obsession with gluten (an obsession that has become fully detached from any serious concern about celiac disease).

Our attention to diets

Here is a Google Trends report of online interest in "dietary guidelines" and "paleo diet", United States, 2004 to the present. Notice the two peaks for interest in "dietary guidelines," corresponding to the release of new Dietary Guidelines for Americans once every five years.

If you are fed up and wish the U.S. could reduce sugar consumption ...

The new documentary movie Fed Up, by Stephanie Soechtig, will be released widely tomorrow. It rightly focuses on sugar consumption as a key contributor to chronic disease in the United States.

If you see this movie and want some links to reliable information, here is a quick rundown of both the diagnosis and the potential solutions.

Diagnosis of the problem

1. Mainstream sources agree with the movie that sugar consumption is a problem. Based on an exhaustive review of the balance of evidence in the scientific literature, the federal government's Dietary Guidelines for Americans plainly recommends that Americans reduce their consumption of calories from added sugars. Fed Up's broad indictment of sugar is endorsed by the movie's most reliable interviewees, such as former FDA Commissioner David Kessler.
2. Sugar is not consumed in the abstract -- it comes from particular foods. As noted in a "Sugar 101" primer from the American Heart Association, the leading sources of added sugars in our diet include soft drinks, baked goods, candy, and ice cream. Americans would live longer and have better health if we reduced consumption of these foods.
3. Unless you are prepared to critically evaluate the complex scientific literature, it is optional and not necessary to buy in to a variety of specific scientific claims about sugar. Among the interviewees in Fed Up's trailer, which I watched today, I have heard nutrition scientist Robert Lustig focus more narrowly on fructose, and I've heard Gary Taubes more broadly criticize all carbohydrates. I personally find the sources cited in #1 above more persuasive than either Lustig or Taubes, but who knows? Either or both of them may turn out right. It doesn't matter for the basic indictment of the foods in #2 above.
4. Some people blame marketing, and others blame federal subsidies. The influence of marketing is real, while the subsidy story is generally unconvincing. To understand how federal subsidies affect corn syrup, for example, one must pay attention not just to price-suppressing corn subsidies (which have been tiny in recent years anyway), but one also must pay attention to corn-based ethanol policies that have made corn syrup more expensive. I think critics of "subsidies" mostly have not taken the time to learn about specific subsidy programs, but rather are expressing -- correctly -- their recognition of the longer term impact of the industrialization of the food system. Regardless, the specific blame doesn't matter much. However we assess the relative contribution of these factors, we should always remember the more fundamental fact that will remain with us even if marketing policies or subsidy policies are reformed: products with sugar are sweet and people desire them. That's the big source of our challenge.

Solutions to the problem

1. Tax. Jenny Hopkinson and Helena Bottemiller Evich report that, in connection with the premier of Fed Up, some in Congress are expressing renewed interest in a tax on sugar sweetened beverages. USDA research shows that an increase in the price of these beverages likely would make a considerable difference on consumption. It is true that part of the gains -- but only part -- would be offset by increased intake of other caloric beverages that substitute for the beverages that are taxed. It is also true that higher beverage prices would be regressive (affecting low income folks relatively more than high income folks). Finally, the most important thing about a tax is that it political death to seek to tax, as if taxes were a good thing. The only politic way to pursue a beverage tax is to institute it as part of the Congress' unavoidable responsibilities to fund essential government services (such as military and roads), reduce the deficit, and seek to balance the budget. The sound argument is, "so long as we are reluctantly compelled to institute a small sensible tax on something, we might as well save some public health expenditures by placing the tax on sugar sweetened beverages."
2. The food environment. I think it is time for schools, offices, restaurants, and all sorts of public venues to revisit their role in making sugary foods -- and especially beverages -- available to excess. At one time in the past, somebody might have seemed overwrought or joyless for enforcing limits on bake sales in schools, for example, or an occasional fast food meal as a reward for good school performance. But, decades into the current nutrition dilemma, I think we should be more grateful and supportive of those who propose holding a firm line on making the food environment healthier, especially for our children.
3. Improving nutrition assistance programs. First, nobody should even contemplate any part of solution #3 unless they also are boldly supporting proposals in #1 and #2. It is poisonous to discuss improving changes to nutrition assistance programs for low-income Americans unless we are firmly on the record supporting corresponding changes in the food environment for people of all income groups. Second, any proposed improvements should incorporate input from anti-hunger advocates as well is public health advocates, and they certainly should draw on input from program participants themselves. If bold new nutrition assistance program options are pursued on a pilot scale, we may be surprised at the response from program participants.

Dietary guidelines and health

[An excerpt from Chapter 8 in Food Policy in the United States: An Introduction (Routledge/Earthscan, 2013).]

It is sometimes said that there is no need for a government role in dietary guidance, because people know how to eat well and simply lack the willpower to do so. Is it true that people in the United States already know how to eat healthfully? While many nutrition and health experts say that something is wrong with U.S. eating patterns, they disagree about what is unhealthy.

Consider four perspectives, which each have a large public following:

• A long tradition, including the physician Robert Atkins and the science writer Gary Taubes, blames carbohydrates for weight problems and recommends a diet that may be high in meat and saturated fat (Taubes, 2007).
• An equally well-developed tradition encourages a low-fat plant-based diet and blames meat consumption for health problems (Campbell and Campbell, 2007).
• The respected epidemiologist Walter Willett and colleagues at the Harvard School of Public Health advise a mostly plant-based diet that is not necessarily low in fat, allowing plenty of vegetable oils (Willett et al., 2005).
• Others, including former FDA Commissioner David Kessler and journalist Michael Pollan, are most concerned about the highly palatable artificial creations of an industrial food system (Kessler, 2009). 

These views about diet and health are partly overlapping and partly contradictory. Yet at least some scientific research in peer-reviewed journals can be found to support each one. To make sound judgments, a layperson needs a skeptical attitude towards dietary fads and a trustworthy summary of the balance of the scientific evidence.

One influential summary of the scientific evidence is the federal government’s Dietary Guidelines for Americans (U.S. Department of Agriculture and U.S. Department of Health and Human Services, 2011). The federal government issued the first Dietary Guidelines in 1980 and has revised the document every five years since then. Regardless of a reader’s own views on diet and health, it is useful to understand the mainstream position of the Dietary Guidelines on controversial questions in nutrition science.

The Dietary Guidelines for Americans is used as a source of evidence for claims about diet and health on food labels (see Chapter 9). It provides key inputs for USDA’s Thrifty Food Plan and other model diets for people at different income levels (see Chapter 10). It informs policies and regulations for nutrition assistance programs, including school lunch and school breakfast (see Chapter 11).

This chapter covers how the federal government develops and uses dietary guidance. The chapter:

• reviews historical trends in chronic disease and nutrition, so that we can pay the most attention to the most important health concerns (Section 8.2); 
• considers several market failures that have been cited as motivation for a government role in dietary guidance (Section 8.3);
• explains the process of creating the Dietary Guidelines for Americans and related consumer-oriented graphics (Section 8.4);
• compares current U.S. consumption patterns to the Dietary Guidelines (Section 8.5); and
• explores several policy instruments that have been proposed to guide Americans toward healthier food choices (Section 8.6).

A debate in NYC over soda policy

Heritage Radio Network has posted in full a debate Thursday night about the NYC soda policy proposals.

The debate had four participants:

• I spoke gently in favor of New York City's effort to experiment with moderate policies to change the environment in which sugar sweetened beverages are marketed and sold.  I suggested that the Board of Health's proposed limit on sweetened beverage container sizes was not as radical as it has been portrayed. My 2-minute opening statement begins at 17:25.
• Lisa Young, an author and adjunct professor at New York University, spoke strongly in favor of the proposal, using cups of various sizes as props to buttress her points.
• J. Justin Wilson trashed the proposal on libertarian and free-market grounds.  Wilson represents the Center for Consumer Freedom, an industry-funded organization that runs ads calling NYC Mayor Michael Bloomberg a nutrition nanny.
• Joel Berg directs the New York City Coalition Against Hunger.  He appealed strongly for broader policies to address U.S. poverty and expressed his organization's intention to neither endorse nor oppose the beverage size limitation proposal.  Then, Berg livened the debate by launching into an enjoyably vivid and highly critical analysis of such paternalistic policies.

The event was organized by the Museum of Food and Drink (MOFAD) and hosted by the New York City Food Policy Center at Hunter College.

Coca-Cola's "Cap the Tap" campaign

The MyPlate consumer education materials (.pdf) from the U.S. government wisely encourage folks to "drink water instead of sugary beverages."

The message from beverage companies is something else altogether.

Through its "Cap the Tap" campaign and related materials, Coca-Cola encourages restaurants to talk customers out of choosing tap water and instead to choose higher-profit items such as Coke, Minute Maid juice, Dasani bottled water, or an alcoholic drink. I read about this campaign recently in a hard-hitting post by Andy Bellatti at Civil Eats. A related link to Coca-Cola's CokeSolutions website appears to be broken now, but I found you can still read about the company's message for restaurants on Google Cache. [Note 11/18/2013: the basic link to CokeSolutions is working.  Bellatti points out by Twitter that the "Cap the Tap" graphic from that site is only available now in a Huffington Post screenshot.  Nice work.]

Bellatti also linked to this great, blunt, fascinating page by graphic designer Pen Williamson, with proposed posters that Coca-Cola could use to get restaurants to discourage healthy and inexpensive tap water as a beverage choice [Note: this sentence edited slightly Nov 15 afternoon]. The poster suggests, "provide tap water to guests upon request only."  I don't know if this poster or another similar poster was used in Coca-Cola's "Cap the Tap" campaign.

There is nothing the government can or should do to restrict this type of marketing to restaurants. Yet, I think it is terrible marketing from a nutrition standpoint, which gives us useful context as we interpret the public policy debate over the potential role of beverage companies as part of the solution to the nation's health and nutrition challenges.

WCRF policy strategies to reduce non-communicable disease around the world

The World Cancer Research Fund (WCRF) this month published a new 2-page document (.pdf) summarizing the organization's recommendations on using food policy to address the problem of high rates of non-communicable diseases (NCDs).

The recommendations encourage clear nutrition labeling, healthy school meals programs, well-targeted taxes and healthy food subsidies, and restrictions on advertising for breastmilk substitutes and for unhealthy foods (especially to children).

The WCRF is an international not-for-profit umbrella organization for a network of cancer prevention organizations. WCRF literature reviews on dietary patterns and cancer risk are used by the U.S. federal government as one of several evidence sources for the Dietary Guidelines for Americans.

The WCRF policy recommendations are bolder and more activist than some policy-makers would be ready to consider in the United States, but the WCRF approach nonetheless offers a lot of insight.  For example, a background document on law and obesity prevention (.pdf) carefully considers both advantages and disadvantages of legal approaches to addressing public health nutrition challenges.  It acknowledges not just the political power of food and beverage manufacturers to thwart such policies but also the constitutional protections for commercial speech and the serious concerns consumers may have about policy interventions that limit their autonomy.

For perspective on U.S. food policy debates, it is illuminating to hear an international perspective that is (not surprisingly) comparatively interventionist, but which at the same time fully recognizes the challenges and tradeoffs involved in such policy proposals.

 

Should federal dietary guidelines address environmental sustainability issues?

The federal government revises the Dietary Guidelines for Americans every five years and currently is working on the next revision, scheduled for completion in 2015.

Traditionally, the guidelines have focused quite narrowly on nutrition issues, although Kate Clancy, Joan Dye Gussow, and a few others have been encouraging greater attention to sustainability issues in connection with dietary guidelines for many years.  During recent times of population growth, changing consumption patterns, and increasingly severe environmental constraints on global food production, it is interesting to ask whether the 2015 guidelines should also address environmental sustainability issues.

In May, 2013, the Institute of Medicine (IOM) at the National Academy of Sciences convened The Food Forum Workshop on Sustainable Diets: Food for Healthy People and a Healthy Planet.  Former USDA Deputy Secretary Kathleen Merrigan was the keynote speaker.

In one session of the workshop, I compared and contrasted the economics of market signals for healthy eating and environmental sustainability.  Here is a slightly shortened video of the talk.  (As always, neither the IOM nor the Food Forum nor anybody else but me is responsible for any errors I make or opinions I offer).  Extensive background material is available in my book, published this year, Food Policy in the United States: An Introduction (Routledge/Earthscan).

In some ways, it is easy to imagine the government offering guidance on environmental aspects of food production just as it offers suggestions on nutrition.  In another sense, the two issue areas are very different.

Here is one difference.  Given the trends of recent decades, it is entirely conceivable that Americans will continue to eat badly for ever more.  There is no automatic nutritional feedback loop that ensures our eating patterns will some day converge in the direction of greater healthfulness.  In the future, we will have healthier nutrition only if we choose to make some change in our current trajectory.

By contrast, it is not physically possible for the world's consumers to eat more than the planet can provide.  If we continue to seek to exceed the planet's productive resources, there will be a reconciliation one way or another.  If we are unfortunate, the reconciliation will involve some manner of crisis, widespread death, and reduced population, until food needs are back in line with productive capacity.  If we are fortunate, the reconciliation will involve moderately higher food prices, especially for animal foods and other foods with comparatively high environmental impact.  These price increases will lead consumers to temper their excesses while simultaneously sending signals to producers to innovate and invest even more fruitfully in new productive capacity.  Whether unfortunate or fortunate, we can no more evade the environmental reconciliation than we can stop the sun from rising.

Interpreting science at #EB2013 in Boston

While enjoying the excellent sessions sponsored by the American Society of Nutrition (ASN) at the Experimental Biology 2013 meetings here in Boston this week, I was struck once again by the way actual nutrition science research results are filtered or digested into short memes of conventional wisdom before they reach the public.

This filtering process is necessary, unavoidable, and even healthy.  And yet it is a key step, which brings politics and interest into the process of producing nutrition policy and dietary guidance.

Here is a passage from my chapter on Dietary Guidance in Food Policy in the United States: An Introduction (Routledge/Earthscan).

Filtering is the process of reading a large body of research and concisely summarizing its relevant points. Because the scientific literature is so heterogeneous, its policy impact depends heavily on how the research is filtered.

Filtering may be biased toward certain types of conclusions. Food industry organizations hire scientists and public relations specialists to spread the good word about favorable studies, without mentioning unfavorable studies. The public relations specialists are evaluated according to their success in placing favorable stories in the mass media. Reporters do not purposely seek to serve as a vehicle for industry public relations, but they face intense pressure to generate buzz by reporting novel and surprising findings. Hence, even though the balance of evidence in the scientific literature changes only slowly, headlines each week tell the public that everything they previously believed about nutrition and health was a big fat lie.

To summarize a complex scientific literature with less bias, scientists prefer to rely on systematic evidence reviews. In a systematic evidence review, an inter-disciplinary team establishes a protocol, a document that describes in advance the procedure for selecting relevant research studies, reducing the temptation to concentrate on studies that are favorable to the team’s prior expectations. For each selected study, the team evaluates the strength of the evidence, again using criteria established in advance.

Systematic evidence reviews do have some limitations. While they can avoid errors that stem from selective reading of just favorable parts of the scientific literature, systematic evidence reviews cannot fix misinterpretations that are widespread in the literature. Also, such reviews may not reflect recent improvements in scientific research. Still, because of their transparency and replicability, systematic reviews can clarify the state of the evidence on contentious scientific issues.

If you are attending the Experimental Biology 2013 meetings this week in Boston, the book itself is on display today at the CRC Press booth (#531 in the exhibition hall).  Please stop by the booth, and please share your thoughts on whether food policy is a worthy topic of study at a meeting of scientists.

An inter-disciplinary approach to U.S. food policy

An excerpt from the first chapter of Food Policy in the United States: An Introduction (Routledge/Earthscan).

The 2010 Dietary Guidelines for Americans, which is the federal  government’s most authoritative official statement on nutrition and health issues (discussed at length in Chapter 8), presents a social and ecological framework for food consumption and physical activity decisions (see Figure). Similar models are found in many other high-profile nutrition policy documents (Institute of Medicine, 2012). To analyze major national problems of obesity and chronic disease, this framework goes far beyond immediate causes such as food and beverage intake and physical activity. Like planetary orbits that are farther from the center, the outer layers list more distant influences on food choices.

The framework calls attention to important topics, including agriculture (Chapter 2), the food and beverage manufacturing industries (Chapter 5), the retailing and restaurant industries (Chapter 6), marketing and the media (Chapter 9) and socioeconomic factors  (Chapter 10). Once nutrition and public health professionals begin to explore these more fundamental influences on food and beverage consumption, they find themselves engaged with challenging topics in economics and political science.

At first, this engagement can be unnerving. When interacting with patients, professionals in medical fields are rightly proud of their ability to diagnose problems and prescribe an appropriate remedy. It is tempting at first to adapt this medical patient approach to food policy applications. For example, if expanding food portion sizes contribute to rising rates of obesity, it is tempting to say government agencies should prescribe smaller portion sizes. If nutrient-dense foods cost too much, it is tempting to say government agencies should prescribe a price ceiling for fruits and vegetables. It is disappointing if policy-makers reject such proposals as politically infeasible. It is downright frustrating if policy-makers say with a straight face that a well-intentioned nutrition policy prescription is unwise. Yet, except in special settings such as school meal programs, determining portion sizes may be a decision that people do not want to delegate to their government. A price ceiling for fruits and vegetables may have unintended consequences, such as reducing the incentives to grow fruits and vegetables.

The outer layers of the social ecological framework bring nutrition policy into contact with many other societal objectives, such as a thriving economy, a healthy environment, poverty alleviation and effective political governance. Powerful policy actors in these outer layers do not—and sometimes should not—behave as if food consumption and physical activity stood alone as the sun at the center of the social ecological solar system. Governments balance food and nutrition concerns against other considerations, just as individuals and families do.

As we explore more deeply the normative question of what food policies best serve the public good, it will appear necessary to discern which decisions should be delegated to governments and which decisions should be made by individuals interacting in economic markets. And, as we explore more deeply the positive question of what policies can win political support, it will appear necessary to anticipate how a variety of producer and consumer interests will respond to such proposals.

These inter-disciplinary explorations are more difficult than simply prescribing the right policy medicine, but ultimately they offer both sharper policy insight and greater potential for political success.

Source: Dietary Guidelines for Americans, 2010.

IOM's Food Forum announces a workshop on sustainable diets, May 7-8

The Institute of Medicine's Food Forum announces an upcoming workshop on a great topic:

Sustainable Diets:

 Food for Healthy People and a Healthy Planet   

May 7-8, 2013

The National Academies Auditorium 

  2101 Constitution Avenue, NW

Washington, DC   

The Institute of Medicine's Food Forum and Roundtable on Environmental Health Sciences, Research, and Medicine are  holding a 1.5 day workshop on “Sustainable Diets: Food for Healthy People and a Healthy Planet.” We hope you will attend. The workshop will explore current and emerging knowledge on the food and nutrition policy implications of the increasing strain on the natural resources in our food system, and seek to further discussion of how to incorporate environmental sustainability into U.S. dietary guidance policies.   

Visit here for more information and to register for the workshop. 

The agenda (.pdf) includes former USDA Deputy Secretary Kathleen Merrigan as keynote speaker, my Tufts colleague Christian Peters speaking about land use effects of dietary patterns, and myself speaking about consumer responses to economic incentives.

U.S. meat consumption fell after 2004

According to USDA data on food consumption per capita, U.S. meat consumption fell from about 2004 to 2010 (the most recent data available).

Beef consumption peaked in 2002 and has fallen about 12% since then.  Pork consumption peaked in about 1999 and has fallen about 11% since then.  And I had not realized that chicken consumption peaked in about 2006 and has fallen almost 5% since then.

Total combined consumption of beef, pork, and chicken peaked in about 2004 and has fallen more than 6% since then.

I think these trends likely are driven both by economic recession and by increasing health and environmental awareness.

Americans consume substantially more beef, pork, and chicken than is necessary for a balanced and healthy diet.  The federal government's mainstream advice on diet and health, MyPlate, suggests that about a quarter of the dinner plate can come from the protein group (which includes fish, seafood, beans, peas, soy foods, nuts, and eggs, in addition to beef, pork, and chicken).

The unusually high U.S. consumption of beef, pork, and chicken also raises environmental concerns, with implications for water quality (when nutrients in manure reach water sources) and land use (because of the large amounts of animal feed that are converted comparatively inefficiently into meat-based foods).

It is worth mentioning that meat is a good source of protein and several other nutrients, but these nutrients are not currently under-supplied in U.S. diets.  Similarly, animal agriculture is a particularly sensible use of certain grasslands that are environmentally unsuitable for crop production, but this grass-based production system is not where most of our beef, pork, and chicken comes from.

Overall, I don't think the government should be too pushy when it comes to influencing people's diets.  It seems quite wise simply to accept and accomodate the recent market-driven downward trends in meat consumption, without taking government action to oppose them.

These trends are a good thing for our health, environment, and economy.
Source: interactive chart by the author using USDA food availability data.

Update (later the same day): I just saw that Steve Baragona at Voice of America yesterday described this same trend.  I had been thinking about this topic, because my colleague Paul McNamara mentioned related work on trends in vegetarian consumption by a student in his department at the University of Illinois, Daniel Karney.

From the Environmental Working Group: Good Food on a Tight Budget

Should dietary guidance advice encompass environmental issues?

The federal government's Dietary Guidelines for Americans document does address some issues beyond just diet, including both physical activity and food safety.  For a number of reasons, environmental issues are not yet included.

But several interesting efforts have gone further.

A classic source is the 1986 article "Dietary Guidelines for Sustainability," by Joan Dye Gussow and Kate Clancy (may be gated).

One more recent resource, which incorporates environmental issues into a dietary guidance graphic akin to MyPyramid or MyPlate is the Barilla Double Pyramid: "Good for you, sustainable for the planet."

Another resource, from Fall 2012, is the "Good Food on a Tight Budget" guidance from the Environmental Working Group.  In this video, EWG's Dawn Undurraga -- a Friedman School alum and former U.S. food policy student -- explains how the guide combines both diet and nutrition issues.

The most droll line in the video comes from a chef, who said (unless I misheard it!): "Income is not consistent with my life right now."

Pretty much everything you read about cancer from authoritative sources is likely to be worth taking seriously

Here is my paraphrase of the most important results from a study by Schoenfeld and Ioannidis in the current issue of the American Journal of Clinical Nutrition:

• Meta-analyses do fairly well at correctly stating their conclusions.  Meta-analyses are quantitative literature reviews that combine results from across studies, essentially increasing the sample size and breadth.
• For example, Schoenfeld and Ioannadis looked at 9 meta-analyses showing an association between consuming particular foods (I think of foods such as fruits and vegetables) and reduced risk of cancer. For all 9, the results were statistically significant at conventional levels (p<.05).
• Schoenfeld and Ioannadis looked at 4 meta-analyses showing an association between consuming particular foods (I think of foods such as processed meats) and increased risk of cancer.  For 3 of the 4, the results were statistically significant at conventional levels (p<.05).
• While the meta-analyses did well at reporting results, individual studies sometimes report results in their abstracts even when they were not statistically significant.  Some of these reported results may be attributed to random happenstance rather than real cancer effects. This is why it is unwise to change eating habits with every new study.  It is wiser to rely on the balance of scientific evidence connecting particular foods to cancer risks and benefits.

Based on these results, you may be interested in the excellent collections of meta-analyses and systematic literature reviews available from a well-respected source such as the World Cancer Research Fund and the American Institute of Cancer Research. The new paper by Schoenfeld and Ioannadis reflects fairly well on the type of research posted by the WCRF and AICR.

But, journalists will report the conclusions of the new study to say something completely different from the above.  In the endless search for novelty, journalists write each day that everything you previously believed about diet and health is mistaken.

For example, Sarah Kliff at the Washington Post's Wonkblog writes today under the headline: "Pretty much everything you eat is associated with cancer. Don’t worry about it." 

Food industry public relations folks will love this message.

To make things worse, Kliff garbles the statistical material (see the comments to the Wonkblog post):

Don’t panic yet, though: The vast majority of those studies, Schoenfeld and Ioannidis found, showed really weak associations between the ingredient at hand and cancer risk. A full 80 percent of the studies had shown statistical relationships that were “weak or nominally significant,” as measured by the study’s P-values.

This description seems to ignore the meta-analyses and also it seems to describe perfectly fine statistically significant results (p<.05) as if they were "weak or nominally significant."

Perhaps the authors share some of the responsibility.  Kliff quotes the author:

“I was constantly amazed at how often claims about associations of specific foods with cancer were made, so I wanted to examine systematically the phenomenon,” e-mails study author John Ioannidis ”I suspected that much of this literature must be wrong. What we see is that almost everything is claimed to be associated with cancer, and a large portion of these claims seem to be wrong indeed.”

As with climate change skepticism, people twist genuine heterogeneity in scientific results to cast doubt on both marginal claims and widely accepted claims alike.  I wish that neither journalists nor authors would cavalierly say that most of the literature is wrong, when even the new study shows quite trustworthy results for the authoritative meta-analyses that actually merit attention from the public.

Just for example, the balance of scientific evidence from WCRF and AICR suggests that fruits and vegetables reduce risk and that red meats and processed meats increase risks of certain cancers.  Such conclusions based on meta-analyses fare well in the new AJCN study.

Are Taubes and Couzens too hard on the Dietary Guidelines?

Gary Taubes and Cristin Kearns Couzens have a remarkable expose in Mother Jones of the sugar industry's misleading public information efforts over several decades.  The feature article stands out for its effective use of previously overlooked archival materials.  The indictment of sugar industry influence on policy advice and nutrition science research is devastating.

Everybody interested in U.S. food policy should read this story.

I do have one substantial complaint.  As in previous work by Taubes, this article does well in describing sugar industry public information campaigns, but it unfairly characterizes the recent editions of the Dietary Guidelines for Americans.

One of the best things about the 2010 Dietary Guidelines, for example, is that any reader can see the systematic evidence reviews -- published free on the internet -- that form the basis for the document's conclusions.

Here is what Taubes and Couzens say about the 2010 Dietary Guidelines:

The authors of the 2010 USDA dietary guidelines, for instance, cited two scientific reviews as evidence that sugary drinks don't make adults fat. The first was written by Sigrid Gibson, a nutrition consultant whose clients included the Sugar Bureau (England's version of the Sugar Association) and the World Sugar Research Organization (formerly the ISRF). The second review was authored by Carrie Ruxton, who served as research manager of the Sugar Bureau from 1995 to 2000.

But following the first link in the preceding paragraph, the federal government's evidence review says exactly the opposite of what Taubes and Couzens claim:

Conclusion.  A moderate body of epidemiologic evidence suggests that greater consumption of sugar-sweetened beverages is associated with increased body weight in adults.

Taubes and Couzens say USDA cited "two scientific reviews," but anybody following the link can see that USDA cited four reviews.  The review that USDA gives most weight was not mentioned by Taubes and Couzens, and it endorses the warnings against sugary drinks.

The whole advantage of systematic evidence reviews is to avoid cherry-picking evidence that favors one's own argument.  I think it would be great for science journalists to adopt the same practice of specifying a selection protocol in advance, just as the federal government's evidence reviews do, so that the journalists are not tempted to report only evidence that corroborates their thesis.

As this blog noted recently, the MyPlate guidance is accompanied by well-crafted terse advice about sugary drinks:

Drink water instead of sugary drinks.

Taubes and Couzens seem right on target in their criticism of the Sugar Association but quite unfair to the federal government and recent editions of the Dietary Guidelines.  (The authors' criticism of earlier editions may be more justified.)  Part of the reason I accept the main thrust of Taubes' critique of sugar-sweetened beverages is that -- despite his tone -- this particular aspect of Taubes' work seems fairly consistent with the sober judgement of mainstream dietary guidance in 2010.

Two communication strategies for reducing sugary drinks

First, I like the plain matter-of-fact tone of the federal government's MyPlate graphic. It paints a pleasant portrait of a healthy meal, and then underlines several key messages for consumers by stating them in blunt English.  One of the key recommendations is to "drink water instead of sugary drinks."

A reasonable person may add that one should drink water instead of sugary drinks most of the time, but the mainstream message of the dietary guidelines reflects the best judgement of scientists in this field.

Balancing Calories

• Enjoy your food, but eat less. 
• Avoid oversized portions. 

Foods to Increase

• Make half your plate fruits and vegetables. 
• Make at least half your grains whole grains. 
• Switch to fat-free or low-fat (1%) milk. 

Foods to Reduce

• Compare sodium in foods like soup, bread, and frozen meals and choose the foods with lower numbers. 
• Drink water instead of sugary drinks. 

Second, in a new video from the Center for Science in the Public Interest (CSPI), public health marketers seek to both imitate and expose the emotive power of soda advertisements.  In the video, a family of polar bears endures the harsh effects of diabetes and learns that the soda advertisements offer only a false promise of happiness.  The video strays close to playing on guilt themes as motivation for healthy behaviors, but the polar bears are fundamentally sympathetic, and they take charge of their own lives in the nice ending. 

If you dislike the video's harsh imagery, I'd be interested to hear about it.  But I do think the beverage association spokesperson's rebuttal -- in a USA Today article -- rings false:

But ABA spokeswoman Karen Hanretty says, "CSPI is better at producing videos than they are doing math. People are drinking fewer calories from soda -- and have been for a decade -- so how can soda be to blame for rising obesity?" 

The basic message that it is better to limit sugary drinks is well-established and denying this with misleading trend statistics just makes the video look like the more serious party in this conversation.