by Marion Nestle

Currently browsing posts about: Obesity

Jan 9 2013

Let’s Ask Marion: Can It Really Be Healthier To Be Overweight?

Every now and then, Kerry Trueman challenges me with a difficult question about some current topic.  Our most recent exchange, published yesterday in the Huffington Post, is about the so-called “obesity paradox” (defined below).

Trueman: There’s a brouhaha in the blogosphere over Paul Campos’ NY Times op-ed in which he claims that our current definition of what constitutes a ‘healthy weight’ is dead wrong. Campos cites a new analysis from The Journal of the American Medical Association claiming that overweight or obese individuals have a lower mortality rate than people whose weight is ‘normal.’

He speculates that our obsession with obesity is a misguided and manufactured controversy foisted on us by the multibillion dollar weight loss industry and Big Pharma. Marion, you’ve been called a lot of things over the years, but have you ever been accused of being in cahoots with Jenny Craig and Eli Lilly?

Nestle. I love it when people invoke conspiracy theories to deny that obesity raises disease risks.

Paul Campos is a lawyer. He views matters of diet and health from a legal perspective. From that viewpoint, if a statistical analysis shows little effect of obesity on mortality except among very obese people, then nobody need be concerned about weight gain except at the extreme.

If only the science of diet and health were that simple. Scientists, alas, must struggle with a number of vexing questions about such studies:

  • Does a finding of statistical significance necessarily imply clinical or biological significance?
  • Do statistical findings based on populations necessarily count for individuals?
  • Do statistical associations provide guidelines for behavior?
  • Are the methods used in statistical studies adequate to draw conclusions about behavior?

We are talking here about a huge meta-analysis of 97 studies of obesity and mortality carried out by Katherine Flegal and her colleagues at the National Center for Health Statistics.

When I read papers by excellent statisticians published in prestigious, peer-reviewed journals, I start by taking the results at face value. Then I ask critical questions about what the results might mean.

I found the figures in the paper difficult to follow so I’ve summarized the results below:

RELATIONSHIP OF WEIGHT CATEGORY TO THE RISK OF MORTALITY.

WEIGHT CATEGORY BMI RANGE MORTALITY RISK (RELIABILITY)
Normal 18.5 – 25 1.00
Overweight 25 – 30 0.94 (95% CI, 0.91-0.96)
Obesity, Grade 1 30 – 35 0.95 (95% CI, 0.88-1.01)
Obesity, Grades 2 and 3 >35 1.29 (95% CI, 1.18-1.41)

My interpretation: Compared to people with BMI’s in the normal range, those with BMI’s considered overweight or somewhat obese display no increased risk of mortality. Indeed, those in the obesity grade 1 category may have a slightly reduced risk. The study only finds an increased risk of mortality—by 29%—when the BMI exceeds 35.

My first reaction? This is not news.

Since this is a study of previous studies, we’ve seen results like this before. Flegal herself published a similar analysis in JAMA in 2005. In that paper, she presented the results in a way that is easier to visualize:

RELATIONSHIP OF BMI TO MORTALITY AT VARIOUS AGES

2013-01-08-BMI1.png

2013-01-08-BMI2.png

These earlier results show what is called a “J-shaped” curve, meaning that the risk of mortality increases at BMI’s below as well as above the normal range.

The new study is consistent with these earlier—and equally controversial—results.

But the earlier results point to some of the difficulties in interpretation.

  • What’s going on at the lower end of these curves?
  • Are mortality results skewed by people who are ill and weigh less?
  • Is BMI an adequate indicator of health status?

At the moment, there is no way to answer these questions at a level of precision that might satisfy legal thinkers.

What we do know is that obesity above the normal range sometimes—never always—raises the risk for chronic diseases like type 2 diabetes, heart disease, and others. Risk is about probability. Risk never implies legal certainty.

It seems clear that for some people—perhaps many—having a chronic disease does not cause a decrease in lifespan. Since 1970, people throughout the world have gained slightly more than ten years of life expectancy overall, but are now spending many more years living with injury, illnesses, and disabilities—conditions caused by cigarette smoking, excessive alcohol consumption, and poor diet.

With respect to overweight, this is sometimes called the “obesity paradox,” understood as the survival benefits of modest overweight and obesity for people who already have a specific medical condition.  For them, many studies—not all—show that survival is modestly better at higher weights.

The Flegal study deals only with the statistical significance of the mortality survival component of the paradox. It does not deal with issues related to the effects of obesity on quality of life.

As a result, some of my colleagues have made harsh comments about the study, calling it “a pile of rubbish.”

I wouldn’t go that far. The study is what it is—a statistical meta-analysis. It’s up to scientists and clinicians to figure out whether statistics like these have meaning in the real world.

In the real world, it doesn’t take much overweight to induce type-2 diabetes in susceptible individuals, and many people—not all—with type-2 diabetes can completely eliminate symptoms by losing a few pounds.

Campos may be willing to let his weight go to where it will and take his chances that statistics are on his side. That’s his choice.

As for me, I’d prefer to avoid weight-related illnesses for as long as I can. I’m hedging my bets and continuing to watch my weight.

Nov 16 2012

Chicago emulates New York’s public health policies? Not quite.

Chicago’s Mayor Rahm Emanuel is not exactly Michael Bloomberg when it comes to public health approaches to obesity and chronic disease prevention.

In October, he announced that he’d gotten Coca-Cola, PepsiCo, and Dr Pepper Snapple to agree to post calorie information on vending machines in Chicago government buildings (something that they will have to do anyway whenever the FDA ever gets around to issuing final rules for menu labeling).

At the same time, he announced a health competition between Chicago city workers and those in San Antonio with rewards paid by the American Beverage Association through a $5 million gift.  This partnership was widely interpreted as a ploy to stave off the kind of soda tax and cap initiatives proposed by the Bloomberg administration in New York City.

And now, in yet another deal with soda companies, Mayor Emanuel has accepted a $3 million grant from Coca-Cola to pay for a park district program “to fight obesity and diabetes by offering nutrition education as well as exercise classes run by armed forces veterans.”

If the idea of soda companies funding anti-obesity campaigns strikes you as ironic—don’t sodas have something to do with obesity in the first place?— you need to understand Mayor Emanuel’s point of view.

His stated philosophy is that it’s better “to give people personal responsibility and the information necessary to make the right choices about their health than it is to legislate their behavior.”

Maybe so, but when faced with today’s “eat more” food environment, personal responsibility doesn’t stand a chance.

But wait: Isn’t Chicago making an important environmental change?  Its public schools are banning energy drinks.

Well, almost.

The new policy sets nutrition standards for all vending machine food and a la carte items sold in cafeterias and excludes energy drinks—with one exception: Gatorade, a PepsiCo product, “can only be used after students have engaged in a school sports activity.”

Are public health partnerships with soda companies a good idea?  The money is nice and undoubtedly badly needed, but worth the price?  Mayor Emanuel thinks so.

I’m dubious.

Oct 18 2012

The New England Journal takes on the food industry

Last week’s New England Journal of Medicine weighs in with several commentaries and research articles.  Some of these were published earlier in online versions:

And this week, it has another on using tax strategies to promote public health.

It looks to me as though the health establishment is finally catching on to what obesity is really about and giving serious thought to what to do about it.  This is important work.

Oct 1 2012

Military officers say school junk food and sodas make kids too fat to fight

The politics of obesity in the United States has no lack of irony.

On the one hand, representatives Steve King (R-Iowa) and Tim Huelskamp (R-Kansas) have introduced legislation—the No Hungry Kids Act—to repeal USDA nutrition standards for school meals.

Why would they do this?   Because they are concerned that students, poor things, won’t get enough to eat.

On the other hand, Mission Readiness, a group of retired military officers, has released Still too Fat to Fight, a report arguing that junk foods and sodas in schools are the reasons why so many young American men cannot qualify for military service.

The report says:

  • About 1 in 4 young American adults is now too overweight to join the military.
  • Being overweight or obese is the number one medical reason why young adults cannot enlist.
  • The U.S. Department of Defense alone spends an estimated $1 billion per year for medical care associated with weight-related health problems.

 Why is this happening?

Students in the United States consume almost 400 billion  calories from junk food sold at schools each year. If the calories were converted to candy bars this would equal nearly 2 billion bars and weigh more than the aircraft carrier Midway.

The military, says Mission Readiness, is doing what it can but “it cannot win this fight alone.  The civilian sector needs to do its part.”

Mission Readiness: start talking to Congress!

Food politics does make strange bedfellows.

Sep 24 2012

Do sugar-sweetened beverages promote obesity? Yes, say papers in the New England Journal.

 The New England Journal of Medicine has just published a series of articles on sugar-sweetened beverages to  coincide with presentations at The Obesity Society’s annual meeting.  Here are links to the articles.  I’ve extracted brief quotes from some of them.  And here’s a summary in the New York Times.

Perspective: J.L. Pomeranz and K.D. Brownell, Portion Sizes and Beyond — Government’s Legal Authority to Regulate Food-Industry Practices.

Regulations that affect “ordinary commercial transactions” (such as the sale of a product) are presumed to be constitutional if they have a rational basis and if the government body enacting them has the appropriate knowledge and experience to do so.

In the case of New York City’s portion-size restrictions, for example, the health department is an expert public health body that reviewed relevant scientific evidence on the health hazards associated with consumption of sugar-sweetened beverages and the effect of portion sizes on consumption patterns. The proposed policy thus has a rational basis….

Original Article: Q. Qi and Others, Sugar-Sweetened Beverages and Genetic Risk of Obesity

The study concludes: “the genetic association with adiposity appeared to be more pronounced with greater intake of sugar-sweetened beverages.”

Original Article: J.C. de Ruyter and Others,  A Trial of Sugar-free or Sugar-Sweetened Beverages and Body Weight in Children

We conducted an 18-month trial involving 641 primarily normal-weight children from 4 years 10 months to 11 years 11 months of age. Participants were randomly assigned to receive 250 ml (8 oz) per day of a sugar-free, artificially sweetened beverage (sugar-free group) or a similar sugar-containing beverage that provided 104 kcal (sugar group). Beverages were distributed through schools….Masked replacement of sugar-containing beverages with noncaloric beverages reduced weight gain and fat accumulation in normal-weight children.

Original Article: C.B. Ebbeling and Others, A Randomized Trial of Sugar-Sweetened Beverages and Adolescent Body Weight

We randomly assigned 224 overweight and obese adolescents who regularly consumed sugar-sweetened beverages to experimental and control groups. The experimental group received a 1-year intervention designed to decrease consumption of sugar-sweetened beverages, with follow-up for an additional year without intervention….Among overweight and obese adolescents, the increase in BMI was smaller in the experimental group than in the control group after a 1-year intervention designed to reduce consumption of sugar-sweetened beverages, but not at the 2-year follow-up

Editorial: S. Caprio, Calories from Soft Drinks — Do They Matter?

These randomized, controlled studies — in particular, the study by de Ruyter et al. — provide a strong impetus to develop recommendations and policy decisions to limit consumption of sugar-sweetened beverages, especially those served at low cost and in excessive portions, to attempt to reverse the increase in childhood obesity.

Clinical Decisions: T. Farley, D.R. Just, and B. Wansink, Regulation of Sugar-Sweetened Beverages

This one is a point/counterpoint.  On the basis of the evidence just presented, should government regulate sugary drinks?

New York City Health Commissioner Tom Farley says yes:

If a harmful chemical in schools were causing our children to get sick, people would demand government regulation to protect them. It is therefore difficult to argue against a government response to an epidemic of obesity that kills more than 100,000 persons a year in the United States and has an environmental origin.7

Federal, state, and local governments already regulate the food system, from farm to retail, in many ways and for many purposes, ranging from support of agriculture to prevention of foodborne illness. The question is not whether we should regulate food, but rather whether we should update food regulations to address this new epidemic.

David Just and Brian Wansink say no:

We must also recognize that the universe of foods that contribute to childhood obesity is much larger than sugar-sweetened beverages. Such a narrowly defined approach would have minimal chance for overall success. Rather, we must consider approaches that will involve parents, schools, and pediatricians in leading children toward more healthful eating habits and increased physical activity. In truth, we cannot hope to create regulations that restrict behavior holistically.

I’d say we now have plenty of evidence that habitual use of soft drinks raises risks for obesity, and plenty of evidence for the need for regulation.

Yes, it would be nice if “leading children to eat better” worked, but parents, teachers, and everyone else needs lots of help in coping with today’s food environment.

The New England Journal has done a great public service in publishing these papers as a series, and the authors all deserve much praise for taking on these difficult research projects.

OK city agencies: get to work!

Sep 19 2012

JAMA publishes theme issue on obesity

Yesterday, JAMA released a theme issue on obesity with several articles of particular interest, starting with New York City Health Commissioner Tom Farley’s Viewpoint.  About portion sizes, Dr. Farley notes:

As publicly traded companies responsive to the interests of their shareholders, food companies cannot make decisions that will lower profits, and larger portion sizes are more profitable because most costs of delivering food items to consumers are fixed….The sale of huge portions is driven by the food industry, not by consumer demand….The portion-size studies strongly suggest that, with a smaller default portion size, most consumers will consume fewer calories.  This change will not reverse the obesity epidemic, but it can have a substantial effect on it.

Lots of interesting food for thought here.  Take a look:


Viewpoint

The Role of Government in Preventing Excess Calorie Consumption:  The Example of New York City
Thomas A. Farley, MD, MPH
JAMA. 2012;308(11):1093 doi:10.1001/2012.jama.11623

The Next Generation of Obesity Research:  No Time to Waste
Griffin P. Rodgers, MD; Francis S. Collins, MD, PhD
JAMA. 2012;308(11):1095 doi:10.1001/2012.jama.11853

FDA Approval of Obesity Drugs:  A Difference in Risk-Benefit Perceptions
Elaine H. Morrato, DrPH, MPH; David B. Allison, PhD
JAMA. 2012;308(11):1097 doi:10.1001/jama.2012.10007

Cardiovascular Risk Assessment in the Development of New Drugs for Obesity
William R. Hiatt, MD; Allison B. Goldfine, MD; Sanjay Kaul, MD
JAMA. 2012;308(11):1099 doi:10.1001/jama.2012.9931

Original Contribution

Exercise Dose and Diabetes Risk in Overweight and Obese Children:  A Randomized Controlled Trial
Catherine L. Davis, PhD; Norman K. Pollock, PhD; Jennifer L. Waller, PhD; Jerry D. Allison, PhD; B. Adam Dennis, MD; Reda Bassali, MD; Agustín Meléndez, PhD; Colleen A. Boyle, PhD; Barbara A. Gower, PhD
JAMA. 2012;308(11):1103 doi:10.1001/2012.jama.10762

Association Between Urinary Bisphenol A Concentration and Obesity Prevalence in Children and Adolescents
Leonardo Trasande, MD, MPP; Teresa M. Attina, MD, PhD, MPH; Jan Blustein, MD, PhD
JAMA. 2012;308(11):1113 doi:10.1001/2012.jama.11461

Health Benefits of Gastric Bypass Surgery After 6 Years
Ted D. Adams, PhD, MPH; Lance E. Davidson, PhD; Sheldon E. Litwin, MD; Ronette L. Kolotkin, PhD; Michael J. LaMonte, PhD; Robert C. Pendleton, MD; Michael B. Strong, MD; Russell Vinik, MD; Nathan A. Wanner, MD; Paul N. Hopkins, MD, MSPH; Richard E. Gress, MA; James M. Walker, MD; Tom V. Cloward, MD; R. Tom Nuttall, RRT; Ahmad Hammoud, MD; Jessica L. J. Greenwood, MD, MSPH; Ross D. Crosby, PhD; Rodrick McKinlay, MD; Steven C. Simper, MD; Sherman C. Smith, MD; Steven C. Hunt, PhD
JAMA. 2012;308(11):1122 doi:10.1001/2012.jama.11164

Health Care Use During 20 Years Following Bariatric Surgery
Martin Neovius, PhD; Kristina Narbro, PhD; Catherine Keating, MPH; Markku Peltonen, PhD; Kajsa Sjöholm, PhD; Göran Ågren, MD; Lars Sjöström, MD, PhD; Lena Carlsson, MD, PhD
JAMA. 2012;308(11):1132 doi:10.1001/2012.jama.11792

Surgical vs Conventional Therapy for Weight Loss Treatment of Obstructive Sleep Apnea:  A Randomized Controlled Trial
John B. Dixon, MBBS, PhD, FRACGP; Linda M. Schachter, MBBS, PhD; Paul E. O’Brien, MD, FRACS; Kay Jones, MT&D, PhD; Mariee Grima, BSc, MDiet; Gavin Lambert, PhD; Wendy Brown, MBBS, PhD, FRACS; Michael Bailey, PhD, MSc; Matthew T. Naughton, MD, FRACP
JAMA. 2012;308(11):1142 doi:10.1001/2012.jama.11580

Dysfunctional Adiposity and the Risk of Prediabetes and Type 2 Diabetes in Obese Adults
Ian J. Neeland, MD; Aslan T. Turer, MD, MHS; Colby R. Ayers, MS; Tiffany M. Powell-Wiley, MD, MPH; Gloria L. Vega, PhD; Ramin Farzaneh-Far, MD, MAS; Scott M. Grundy, MD, PhD; Amit Khera, MD, MS; Darren K. McGuire, MD, MHSc; James A. de Lemos, MD
JAMA. 2012;308(11):1150 doi:10.1001/2012.jama.11132

Editorial

Progress in Filling the Gaps in Bariatric Surgery
Anita P. Courcoulas, MD, MPH
JAMA. 2012;308(11):1160 doi:10.1001/jama.2012.12337

Progress in Obesity Research:  Reasons for Optimism
Edward H. Livingston, MD; Jody W. Zylke, MD
JAMA. 2012;308(11):1162 doi:10.1001/2012.jama.12203

Sep 18 2012

Today’s debate: The Wall Street Journal asks who’s responsible for preventing obesity?

Betsy McKay of The Wall Street Journal organized and moderated a debate on this question.  I was a participant along with Brian Wansink , the John S. Dyson professor of marketing at Cornell University and Michael D. Tanner, senior fellow at the Cato Institute.

The debate is lengthy—you can read all of it online—but here are my initial responses to the two questions asked of me.

WSJ: What role should government play in addressing the obesity epidemic?  

DR. NESTLE: The government is up to its ears in policies that promote obesity. To name only a handful: supporting production of food commodities, but not of fruits and vegetables; permitting food and beverage companies to deduct marketing expenses from taxes; permitting SNAP benefits [food stamps] to be used on any food, thereby encouraging food companies to market directly to low-income groups.

Research on the prevalence of obesity shows that after decades of remaining at the same level, it began to increase sharply in the early 1980s. Our sense of personal responsibility did not change then. What did change was the food environment, transformed by food industry imperatives to increase sales, to one that increasingly urged people to “eat more” by making it socially acceptable to eat anywhere, anytime, and in very large amounts. In this kind of food environment, all but the most mindful eaters overeat. Few of us are in that category.

The food, beverage and restaurant industries collectively spend roughly $16 billion a year to promote sales through advertising agencies, perhaps $2 billion of that targeted at children. Marketing to children is well established to encourage kids to want advertised products, pester their parents for them, and believe that those products are what they are supposed to be eating. The “I am responsible” argument does not work for children (I’m not aware of evidence that it works well for adults either). Because regular consumption of junk foods and sugary drinks is linked to obesity in children, marketing these products to them is overtly unethical.

To expect food and beverage companies, whose sole purpose is to increase sales and report growth in sales every quarter, to voluntarily stop marketing to children makes no sense. On ethical grounds alone, government intervention is essential.

Given the personal and economic costs of obesity—currently estimated at $190 billion a year—governments have many reasons to promote the health of their populations. Just ask the military.

WSJ: Let’s talk about some specific initiatives. Will Mayor Bloomberg’s cap on soda sizes reduce soda consumption? What about the proposed municipal tax of a penny an ounce on sugary drinks in Richmond, Calif.?

DR. NESTLE: If only education and personal responsibility worked to improve eating behavior. Brian Wansink’s research clearly shows that his own students, diligently educated to understand the effect of large food portions on eating behavior, will still eat more when given more food—and, more seriously, they will underestimate the amount they have eaten.

Education must be backed up by a supportive environment. So why not create a food environment that makes it easier for people to eat less? Mayor Bloomberg’s idea of capping soda sizes at 16 ounces is an interesting approach to doing just that. A 16-ounce soda is not exactly abstemious. It is two standard servings, 50 grams of sugar and 200 calories.

To suggest that food laws will not change behavior makes little sense. For one thing, anti-obesity initiatives have scarcely been tried. For another, the history of anti-smoking interventions suggests quite the opposite. Attempts to get smokers to quit by invoking personal responsibility made little headway. Smokers quit when the government made smoking so inconvenient and expensive that it became easier to stop than to continue.

The intense response of soda companies to Mayor Bloomberg’s cap on soda size is testimony to the effectiveness of regulatory approaches. The companies would not be putting this kind of effort or spending millions to oppose an action they expected to fail.

Aug 28 2012

PepsiCo donates $100,000 to National Association of Hispanic Journalists

A blog post from Fernando Quintero on the Berkeley Media Studies Group’s site alerted me to PepsiCo’s latest example of corporate social responsibility: an additional $50,000 donation for scholarships and internships to the National Association of Hispanic Journalists bringing the total to $100,000.

Hispanic populations in the United States have higher than average rates of obesity, type 2 diabetes, and other chronic conditions associated with overconsumption of sodas and snacks.

Such generosity raises questions about what Pepsi is buying from this group.

The NAHJ says:

We are thrilled to have PepsiCo as a new partner committed to building a stronger Latino community,” said Ivan Roman, Executive Director for NAHJ. “The company’s support as we get more Hispanics into journalism to tell our stories is key to making sure our communities are represented fairly in the news media, while giving them a louder voice in the civic dialogue.

Why do I think that journalists in this Association are unlikely to be telling stories like these:

  • The relationship of soda and snack consumption to obesity and type 2 diabetes in Hispanic communities
  • The relationship of soda and snack consumption to Hispanic childhood obesity
  • How soda intake among Hispanic children leads to dental decay
  • Soda company marketing practices in Hispanic communities
  • The effects of soda and snack marketing on dietary practices and health in countries in Latin America

Pepsi says:

As part of La Promesa de PepsiCo, the company is building relationships with the community, strengthening its strategic partnerships, and sponsoring national Hispanic organizations like: CHCI (Congressional Hispanic Caucus Institute), HACR (Hispanic Association on Corporate Responsibility), LULAC (League of United Latin American Citizens), NAHJ (National Association of Hispanic Journalists), and NCLR (National Council of La Raza) among others.

A page from the tobacco-industry playbook, no?