by Marion Nestle

Currently browsing posts about: Dietary-Guidelines

Mar 21 2014

Yesterday, food studies under attack. Today, it’s the dietary guidelines

The food movement must be succeeding beyond anyone’s wildest expectations.

Now it’s the Dietary Guidelines Advisory Committee’s (DGAC’s) turn to come under attack.

The Guidelines:  These are principles of healthful diets aimed at policymakers  (not the general public).

The history:  They have been published every five years since 1980, so we are now in round #8 scheduled for publication in 2015.

The process: Two federal departments, USDA and Health and Human Services, appoint an advisory committee of nutrition scientists.  The committee reviews the science and prepares a report.  Since 2005, the agencies have written the guidelines, not the committee.     

Disclosure: I was a member of the advisory committee for the 1995 Guidelines.

The fireworks: According to ProPolitico Morning Agriculture (behind a pay wall, alas), the committee is attracting unusual attention from the right:

  • The Washington Examiner, writes that “committee members…are hijacking the guidelines to advance a range of ideological agendas having nothing to do with healthy eating.”
  • The Daily Caller asks “Are Progressives Inserting Their Agenda Into Your Diet?” Tuesday.
  • The Washington Free Beacon wants you to “Meet the Radicals Creating the New Federal Dietary Guidelines.”

A clue to what is upsetting these folks comes from the committee’s request for public comments.  It is asking for comments that address:

  • Elements of a whole food system
  • Information on specific food groups or commodities
  • Sustainability metrics that have been implemented or are in development

These, apparently, are fighting words.

Yesterday, Fox News asked why “ivory tower types” were in charge of determining food choices for Americans.

Its story particularly singled out Miriam Nelson, a professor at Tufts (not New York University—could Fox be confusing her with me?):

New York University professor Miriam Nelson, said at the committee’s last meeting, “We need to make sure that the guidelines and the policies are promoting those foods … [that] are sustainably grown and have the littlest impact on the environment.”

…The professors of the DGAC may think their job is save the planet by promoting sustainable agriculture and plant-based diets, but if they don’t understand the real-world implications of their work, they’ll be oblivious to the havoc they’ll wreak on the millions of Americans whose diets hinge on their guidelines.

By this time, the Dietary Guidelines are hardly of interest to anyone but policy wonks (really, they never change all that much).  Cheers to the current committee for injecting some life into them.

The 2015 Guidelines will be fun to watch.

Mar 19 2014

Is saturated fat a problem? Food for debate.

What is a poor eater to do?

The latest meta-analysis of the effects of saturated fat on heart disease finds—none.

This study, reported in the Annals of Internal Medicine (doi: 10.7326/M13-1788), examined the results of

  • 32 observational studies involving 530 525 participants
  • 17 observational studies involving 25 721 participants
  • 27 randomized controlled trials involving 103 052 participants

The result?

Current evidence does not clearly support cardiovascular guidelines that encourage high consumption of polyunsaturated fatty acids and low consumption of total saturated fats. 

This meta-analysis follows an editorial in a Mayo Clinic publication (http://dx.doi.org/10.1016/j.mayocp.2013.11.006) by authors who argue that saturated fat is not the problem.  Carbohydrates (e.g., sugars) are the problem.  The authors argue:

  • Effects of saturated fat on blood cholesterol are weak and transient.
  • Meta-analyses have found a lack of an association between heart disease mortality and saturated fat intake.
  • Stroke studies find that patients with stroke had eaten less saturated fat.
  • Long-term studies find that people with the highest dairy consumption have the lowest mortality risk, and also low diabetes and heart disease.
  • Dietary trials find trivial or no benefit at all from decreasing saturated fat and/or increasing intake of polyunsaturated fat.

On this basis, they say that advice to reduce intake of saturated fat is irrational.

The New York Times asked several experts for comment on the meta-analysis, among them Dr. Frank Hu of Harvard:

The single macronutrient approach is outdated…I think future dietary guidelines will put more and more emphasis on real food rather than giving an absolute upper limit or cutoff point for certain macronutrients…people should try to eat foods that are typical of the Mediterranean diet, like nuts, fish, avocado, high-fiber grains and olive oil.

Dr. Hu was referring to a large clinical trial (not included in the meta-analysis), which concluded that a diet with more nuts and extra virgin olive oil reduced heart attacks and strokes when compared with a lower fat diet with more starches.

The Times story contained a reminder that the American Heart Association issued dietary guidelines last year to “restrict saturated fat to as little as 5 percent of their daily calories, or roughly two tablespoons of butter or two ounces of Cheddar cheese for the typical person eating about 2,000 calories a day.”

How to make sense of this?

I vote with Frank Hu that dietary advice should focus on food, not nutrients.

Focusing on one or another nutrient—fat, saturated fat, cholesterol, or sugar—takes foods out of their caloric as well as dietary context.

My guess: If you balance food intake with physical activity and are not overeating, the specific proportion of fat, carbohydrate, and protein won’t matter nearly as much.

While the arguments about fat v. sugar go on and on:  Eat your veggies, vary the foods you eat, don’t gorge, and enjoy what you eat.

Feb 19 2014

Brazil’s new dietary guidelines: food-based!

Brazil has issued new dietary guidelines open for public comment.  For the Brazilian Dietary Guidelines document (in Portuguese), click here..

Brazilian health officials designed the guidelines to help protect against undernutrition, which is already declining sharply in Brazil, but also to prevent the health consequences of overweight and obesity, which are sharply increasing in that country.

The guidelines are remarkable in that they are based on foods that Brazilians of all social classes eat every day, and consider the social, cultural, economic and environmental implications of food choices.

The guide’s three “golden rules:”

  • Make foods and freshly prepared dishes and meals the basis of your diet.
  • Be sure oils, fats, sugar and salt are used in moderation in culinary preparations.
  • Limit the intake of ready-to-consume products and avoid those that are ultra-processed.

The ten Brazilian guidelines:

  1. Prepare meals from staple and fresh foods.
  2. Use oils, fats, sugar and salt in moderation.
  3. Limit consumption of ready-to-consume food and drink products
  4. Eat regular meals, paying attention, and in appropriate environments.
  5. Eat in company whenever possible.
  6. Buy food at places that offer varieties of fresh foods. Avoid those that mainly sell products ready for consumption.
  7. Develop, practice, share and enjoy your skills in food preparation and cooking.
  8. Plan your time to give meals and eating proper time and space.
  9. When you eat out, choose restaurants that serve freshly made dishes and meals. Avoid fast food chains.
  10. Be critical of the commercial advertisement of food products.

Now if only our Dietary Guidelines Advisory Committee would take note and do the same?

Would you like us to have sensible, unambiguous food-based guidelines like these?  You can file comments on the 2015 Dietary Guidelines here.

Thanks to Professor Carlos A. Monteiro of the Department of Nutrition, School of Public Health at the University of Sao Paulo for sending the guidelines and for their translation, and for his contribution to them.

Jan 13 2014

What are Americans eating?

I’ve only just come across this USDA chart, which first appeared in an article in Amber Waves.

USDA’s Economic Research Service (ERS) researchers looked at 1998-2006 grocery store food expenditures and compared what consumers buy to dietary guidelines for healthy eating.  

Oops.  

Jun 13 2013

The endless debates about salt: Don’t worry. Eat (real) food

Since 1980, U.S. dietary guidelines have advised eating less sodium (salt is 40% sodium, 60% chloride).  Although sodium is an essential nutrient, most Americans consume way more than they need or is good for them—around 3,400 milligrams a day.

The 2010 guidelines advised healthy people to consume no more than 2,300 mg per day (~6 grams, or 1.5 teaspoons).  They advised even less, 1,500 mg, for people with or at high risk for high blood pressure.  Since blood pressure increases with age in countries with high salt intake, this applies or will apply to just about everyone.  

In 2011, the Institute of Medicine said it was imperative to find effective strategies to lower salt intake.  This means dealing with processed and restaurant foods, because that’s where most of the salt comes from, as can be seen from this list of major food sources

Because consumers have no choice about the amount of salt in processed and restaurant foods, education cannot be enough to achieve salt reduction.  Scientists in Australia have just proved this point.

As I explained to a reporter,

Why anyone would think that nutrition education alone would change behavior is beyond me. By this time everyone should know that to change behavior requires not only education, but a food environment—social, political, economic—that supports and promotes the behavior change.

Most dietary sodium comes from processed foods, restaurant foods, and other pre-prepared foods.  All the label can do is say ‘don’t eat me’ It can’t help with what people can eat.

The easiest and most effective way to help people reduce sodium intake is to require food producers and food preparers to use less of it. Good luck with that. I’m not optimistic, particularly given the conflicting and confusing science. 

Ah yes.  The conflicting science.  The IOM now says that there’s no evidence one way or the other that reducing sodium below 2,300 mg per day, or even to 1,500 per day, does much good, and that low sodium intakes could be harmful (but this too is controversial).

Yes, they could, but as Mark Bittman blogs,    

It may be true that there are no benefits in an ultra-low-salt diet, but almost no one is eating an ultra-low-salt diet. It’s not quite like worrying about whether we get “enough” sugar, but it’s nearly as ridiculous.

And now, as Food Navigator explains, the IOM committee is complaining that its report has been badly misinterpreted.  All they said was:

As to whether we should cut back to 1,500 mg or to 2,300 mg sodium a day, meanwhile, the jury is out, says the IOM, not because consuming 1500 mg/day is dangerous, but because there is just not enough data on the benefits of consuming such low levels to support a firm conclusion.

IOM committee members were so bothered by misleading press accounts that they wrote an op-ed to JAMA to clarify:

Rather than focusing on disagreements about specific targets that currently affect less than 10% of the US population (ie, sodium intake of <2300 mg/d vs <1500 mg/d),  the IOM, AHA, WHO, and DGA are congruent in suggesting that excess sodium intake should be reduced, and this is likely to have significant public health effects. Accomplishing such a reduction will require efforts to decrease sodium in the food environment….

The bottom line, Bittman says (and I enthusiastically agree), is that

Salt intake — like weight, and body mass index — is a convenient baseline for public policy people to talk about. If you focus on eating less salt — and, indeed, less sugar — you will inevitably eat less processed food, fast food, junk food (it’s all the same thing.) If you eat less processed food (etc.) you eat more real food. If you eat more real food, not only are you healthier, but you probably don’t have to pay attention to how much salt you’re eating. Wowie zowie. 

Oct 22 2012

Rest in peace George McGovern

Former Senator (D-SD) George McGovern died yesterday at age 90.

His accomplishments as a Senator and statesmen were legion, many of them strongly connected to food politics.

As I mentioned in 2009 when I gave the state department’s annual George McGovern lecture in Rome, he chaired the Senate Select Committee on Nutrition and Human Needs from 1968-1977.   This committee greatly expanded food assistance programs and then developed the first federal guidelines for chronic disease prevention: Dietary Goals for the U.S.

In Food Politics, I described the work of this strongly bipartisan committee (Bob Dole was its lead Republican member) and how it did so much to improve the lives of women and children living in poverty in the United States, and of poor people throughout the world.

The committee also broke new ground in shifting nutrition education from a focus on eating more of a variety of foods to eating less of foods that increased risks for chronic disease.

What’s shown here is the February 1977 version of this landmark report.  As the result of outraged protests by food producers affected by the “eat less” messages, the committee was forced to tone down its recommendations.  The committee issued a revised report in December that year.

That was the committee’s final act.  Congress disbanded it and McGovern lost his bid for reelection.

McGovern leaves an extraordinary legacy, one unimaginable in this era of partisan politics.

He was far ahead of his time, as this 1977 photo shows.  It is a fitting tribute.

Mar 9 2012

The Lancet on nudging and nagging vs. environmental change

I’m getting caught up on my journal reading and just ran across an editorial from The Lancet, January 21It takes on the UK government’s “personal responsibility” approach to health promotion based on the idea that

gently ‘nudging’ people to change their unhealthy behaviours was the key to public health.

Even the UK government has to admit that the nudge approach isn’t working.  Now it is telling physicians in the National Health Service (NHS) to nag:

use every contact with patients and the public to help them maintain and improve their physical and mental health and wellbeing.

The Lancet asks:

Is this a realistic, sensible, and effective recommendation? We would say not.

Effective, evidenced-based public health measures do not include nudging people into healthy behaviours or getting NHS staff to lecture patients on healthy lifestyles.
They include measures such as raising taxes on cigarettes, alcohol, fatty foods, and sugary drinks, reducing junk food and drink advertising to children, and restricting hours on sale of alcoholic drinks….Focusing on other approaches is foolish.
The nudge and nag approaches need one thing: the firm elbow.
I do enjoy reading The Lancet.  Its editors are so clear about the need for environmental changes to make it easier for people eat better diets and be more active.
Jan 5 2012

The new study of protein and weight gain: calories count!

I was intrigued by the new study from the Pennington Research Center concluding that weight gain depends on calories, not how much protein you eat.

The idea that the protein, fat, or carbohydrate content of your diet matters more to weight than how many calories you eat persists despite much evidence to the contrary.

This study did something impressive.  It measured what people ate, how much they ate, and how much energy they expended under tightly controlled conditions.

This is unusual.  Most studies of weight gain and loss depend on participants’ self reports.

Measuring is much more accurate, as I discuss in my forthcoming book with Malden Nesheim, Why Calories Count: From Science to Politics (out April 1).  If you want calorie balance studies to be accurate, you have to measure and control what goes in and out.  The Pennington is one of the few laboratories in the country that can do this.

Pennington researchers got 25 brave people to agree to be imprisoned in a metabolic ward for the 12 weeks of the study.  The volunteers had to eat nearly 1,000 extra calories a day over and above what they needed to maintain weight.  Their diets contained either 5%, 15%, or 25% of calories from protein.

All of the volunteers gained weight (no surprise), although the low-protein group gained the least.  Most of the weight ended up as body fat.  The medium- and high-protein groups also gained muscle mass.  The low-protein group lost muscle mass.

All of the differences in weight gain among individuals could be accounted for by energy expenditure, either as activity or heat (protein causes higher heat losses).

The Wall Street Journal (January 4) did a terrific summary of the results:

This tells you that low-protein diets cause losses in muscle mass (not a good idea), and that there isn’t much difference between diets containing 15% protein (the usual percentage) and higher levels.

The study also suggests that higher protein diets won’t help you lose weight—unless they also help you cut calories.  That calories matter most in weight gain and loss is consistent with other studies based on measurements, not estimations.

Of course the quality of the diet also matters: it’s easier to cut calories if you are eating plenty of vegetables, fruits, whole grains and a varied diet based largely on relatively unprocessed foods—and it’s harder to gain weight on such diets.