Junkfood Science: December 2007

December 31, 2007

What can you buy for $310,000?

The countdown has already begun and the diet season is off and running. It's become our national pastime. Diets don’t actually work to make us thin and certainly don’t make us healthier, by all evidence, but they are extremely effective at one thing: making gobs of money for the weight loss industry. According to Marketdata Enterprises Inc., it’s a $55 billion market just in the U.S. and is expected to reach $61 billion in 2008.

Think about what that means, mostly for women who get swept up in the weight loss frenzy. A recent survey of 2,000 young women by More Magazine found that the average woman spends $5,002 every year trying to achieve a thin body: on diet and fitness aids, gym memberships, exercise tapes, supplements and “healthy” foods and diet products. “Yet, on average, women will only lose up to 3 pounds a year — most of which they put back on — while spending up to [$310,000] over a lifetime on their weight-loss regimes.”

The economic toll on women’s welfare and financial security is staggering. But they also found a number of worrying trends among young women, weight loss techniques which they’d begun at the age of 15:

· Nine out of 10 (90%) had gone at least a day without eating, with 30% starving for two or more days and 7% going more than four days without food

· A fifth (20%) had been eating one day and nothing the next, with half eating only one meal a day

· More than half (53%) felt they needed to eat less than 1,000 calories a day and a fifth (20%) less than 800 calories

· A third (34%) had taken pills trying to lose weight, 30% made themselves sick and 11% had taken speed or cocaine

As disturbing as these desperate measures are, more insidious are the conclusions made by the pollsters: that the reason these diets don’t work is that people aren’t doing it right. Dieting doesn’t work. Their answer is to avoid diet foods and starvation diets and just eat “healthy.” By making small, simple lifestyle changes; and eating healthy, natural foods and avoiding bad foods like sugars; they say, the excess weight will slowly and permanently come off. “Never say diet,” in essence. “By making it a lifestyle, it’s not a diet.”

It’s a diet.

They’re counting on people to not remember that nondieting is a worn diet tactic and nothing new. Just as all diet fads have cycled in and out of fashion, the fad of “no-diet” diets has seen a resurgence over recent years. If it had worked years ago, it wouldn’t be a fad, of course. Sadly, a lot of people become convinced that they’re eating “healthy” or “intuitively” when they’re actually dieting, restricting and restraining their eating.

By making it about “a healthier you,” no-diet diets try to distance themselves from the stigma surrounding fad diets, which everyone knows don’t work.* Jeering at fad diets** also makes for fun and entertaining stories, but merely turns attention away from the fact that the healthy, commercial diets are no more effective.

The questions used to identify fad diets, are the exact same ones we can use to identify any other diet:

· Does it sound too good to be true?

· Does the diet help a company sell products or foods?

· Does it lack scientific evidence?

The latest “it’s a lifestyle choice, not a diet” diet is from Weight Watchers. You can’t miss the nonstop advertisements. “Diets don’t work... Weight Watchers works because it’s not a diet.” Instead, we’re told, WW is about living a healthy life and that will help you lose weight and keep it off.

Making their diet a lifestyle is a clever marketing tactic to sign customers up for life. But it’s still a diet, just as it's been for decades. And what a way to live, constantly focused on food and physical appearance.

Brian at Red 3 was the first to write about this new ad campaign in a feisty series. He noted how the ads have co-opted the very same language the fat acceptance movement had created back in the 1970s. “They co-opted our vocabulary, repurposed our slogans,” he wrote. “The failure of diets [is] no longer a call to advocacy, but a sales pitch for repackaged diets.”

When the WW ads first started appearing on billboards and the internet earlier this month, he noted that a web search for ‘Weight Watchers’ + ‘diet’ yielded 594,000 hits. “I guess they must all be talking about how they aren’t on a diet,” he wrote.

“Losing weight is as easy as holding your breath,” he wrote. “Keeping it off is as easy as continuing to hold your breath.”

There is one way diets do work and only one. Here is another example: Weight Watchers International, Inc. is the world’s largest weight management company and recently announced its third quarter net revenues had increased 18.5% ($52.7 million) to $337.5 million. Just in the first nine months of this year, it had made $1,123.1 million. No doubt, it anticipates a happy new year.

* For more reading, Lindsay is compiling an online resource called “Diets Don’t Work.”

** This has been a year filled with wacky diets... that people have actually spent money on. Here are just a few:

Air Diet

Apple-a-day Diet (endorsed by the newly-appointed executive director of the U.S. Department of Agriculture Center for Nutrition Policy and Promotion)

Beck Diet (‘think thin’ diet)

Best Life Diet (changing habits)

BioSlim Diet (reviewed in March)

Blood Type Diet (another blood type diet)

Body ID Plan (a personal diet based on blood tests of immune reactions)

Cabbage Soup Diet

Calorie Shifting/Calorie Cycling

Cardio-Free Diet

Caveman Diet

Cell Phone Diet

Chi Diet (based on Chinese Zodiac)

Cinnamon, Lime Juice and Vinegar Diet

Coconut Diet

Diet Fork (short dulled teeth prohibit picking up large forkfuls of food)

Facial Analysis Diet

Fat Flush Diet

5 Factor Diet (5-week celebrity diet)

Fruit Diet

1st Personal Diet (another blood test diet)

Good Mood Diet (high carb, to complement the numerous low-carb diets)

Grapefruit Diet

Hot Diet (cold beverages are purported to prevent weight loss)

Hypnosis Diet

Hypnoanalysis Diet

Intuitive Eating and Emotional Freedom Technique (“diets don’t work, lose weight without dieting; there are other versions)

Master Cleanse Diet

No Crave Diet

Reverse Diet (dinner for breakfast)

Secret Diet (another ‘think thin’ plan)

Shoe Diet (cognitive behavioral techniques)

Step Diet

Thin-Link (HealthPartners is in on this diet, remote monitoring using daily accountability to keep you on your diet)

Thrive Diet (promises a lean body, sharp mind, and everlasting energy)

Warrior Diet (nocturnal eater diet)

Water Diet

Information on how these diets work can be found here.

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December 30, 2007

“If all else fails, we could try science.”

There was a bold and thoughtful article in the New England Journal of Medicine this past week that received no notice in mainstream media but deserved to. It offered valuable insights into the importance of evidence-based clinical guidelines — that are really based on the evidence — and why this is a vital issue for us, as well as our doctors.

How readily will doctors be to object to guidelines — such as for obesity, diabetes, and heart disease management — that they don’t agree are sound or to be in the best interests of their individual patients? Or are the costs of doing so too great? This article offered revealing insights into the dilemmas faced by doctors under growing pressures to comply with the clinical guidelines being issued by third parties, such as government agencies or insurance companies.

Doctors are finding their medical care being monitored and evaluated by how well they comply with these performance measures. Failing to conform, costs doctors reimbursement and referrals, and increasingly means risking malpractice charges. Called P4P measures (pay-for-performance), these are being instituted under the guise of quality improvement and improving patient outcomes.

But do they?

The series on P4P (here, here, here and here) has revealed that these measures aren’t always the result of impartial examinations of the evidence nor do they necessarily translate into better care and clinical outcomes. In fact, most are considerably more controversial than commonly presented in the media. There are even multiple and different “evidence-based” guidelines for the very same disease, depending on which professional organization or insurer issues them. Concerns have been raised that because they are one-size-fits-all care algorithms created from statistical data on populations, and frequently issued by third party payers with financial incentives, they are not always best for individual patients and their unique personal situations and wishes.

The latest issue of American Medical News underscored the problem of clinical practice guidelines, each of which only addresses a single disease, as being “woefully inadequate” for caring for real patients and real life situations. People rarely just have a single disease, as a study just published in the Journal of General Internal Medicine (online link not available) found. It was led by Dr. Eve Kerr, M.D., MPH, associate director for the VA Ann Arbor Health Services Research and Development Center for Clinical Management Research and associate professor of internal medicine at the University of Michigan Medical School in Ann Arbor. Examining 1,900 seniors with diabetes, they found 92% had at least one other chronic health problem, with half having three or more additional diseases. Each condition has competing demands and caring for the whole patient means weighing numerous issues. According to an editorial by Dr. Pugh, M.D., “we need to take care of the whole person, not just their heart, knee or pancreas, and to truly let that person be the decision-maker with the care team providing information and support.” P4P measures don’t enable these types of clinical judgments.

Clinical guidelines were once be clinical guides for physicians, to assist them in managing their individual patients, but now they “have grown teeth,” said Dr. Mark Vonnegut, M.D., a pediatrician in Quincy, MA, and the insurer withholds money for every metric not met. “Having teeth means these programs come down as edicts; they may or may not have a scientific basis or be applicable to our practice or population, but we must either go along with them or go out of business,” he said.

Writing in the current issue of the New England Journal of Medicine, he laments that: “We have gone from doing the right thing for the patient no matter what, to doing the right thing for the patient as long as it doesn't hurt our hospital or practice or the insurance company too much.”

His article, “Is Quality Improvement Improving Quality? A View from the Doctor's Office,” goes on to express concerns about the effects these measures will have on medical care. Dr. Vonnegut asks: Do we really want doctors who are motivated by getting good scores from insurers and earning performance bonuses? Or will these overcome the capacity for critical thinking and reliance on empirical data? All of the time he spends documenting his compliance with P4P measures for asthma or obesity and other initiatives, he says, is time he’s not spending taking care of his patients. But the bigger concern may be in how these measures risk discriminating against people most in need of care, as those paying for healthcare become more concerned with managing costs. As he writes:

At this point, the notion that any of these programs actually improves the quality of care is speculative and debatable. With the health-maintenance-organization (HMO) model of health care delivery, it quickly became clear that it was advantageous to take care of people who didn't need much care. Avoiding unemployed and poor people was generally a good idea, because they tend to have more problems. There was a great deal of talk about preventive care, but what really happened, as far as I could see, was that successful HMOs were able to siphon off billions of dollars and become the corporations they are today by taking care of young, healthy, employed, middle-class people....

The consequences of third-party payers who are also managing clinical performance means “the incentives for getting rid of sick and poor patients will be stronger than ever,” he said:

I can't help suspecting that underneath all these quality-improvement and pay-for-performance initiatives lies yet another scheme that will work out very well for insurers and very badly for providers and patients. The tens of thousands of dollars I'm going to lose out on for failing to achieve my electronic-prescribing or obesity-management goals has certainly caught my attention, but it's not the big prize.

The big prize, he says, will come from making doctors increasingly dependent on trying to meet these quality and cost-containment goals, while distracting them from patient care. Moreover, overhead will go through the roof. Practices such as his already require a full-time nurse and secretary dedicated to dealing with these initiatives. He added:

Meanwhile, U.S. doctors today have less and less to say about the care of their patients. All the complex lessons they learned in medical school are being swept aside for template care.... And if these so-called quality-improvement programs turn out to be elaborate cost-shifting schemes, many sick people will be deprived of medical care, and the overall costs for all of us will go up.

At a minimum, we should be working harder to determine whether these programs really will improve care before adopting what is a very radical and far-reaching change in the way medical care evolves and is delivered. If we adopt a multitude of quality measures that have not been validated, we are very likely to end up with more quality problems than we started with. We all went to medical school — if all else fails, we could try science.

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December 29, 2007

Part Two: What does the evidence reveal? Can diets work?

There have been multiple reviews of the evidence examining the effectiveness of obesity treatments, dating back to the 1970s. What all of these have consistently demonstrated is that no weight loss intervention has been shown to be effective in producing lasting weight changes. More importantly, no clinical study has ever shown weight loss actually improves life expectancy. In fact, some suggest weight loss increases the risks for premature death. Reviews from the U.S. Preventive Services Task Force, National Institutes of Health, and Federal Trade Commission have already been discussed at JFS. In part two, we’ll look at three other comprehensive reviews of the evidence.

The failure of diets

Professors and clinicians David Garner, Ph.D., and Susan Wooley, Ph.D., reviewed 500 studies on dieting and weight loss to evaluate long-term treatment efficacy, the biology of weight regulation, and health outcomes. Their 1991 paper, “Confronting the Failure of Behavior and Dietary Treatments for Obesity,” remains one of the most important documents examining the failures of current obesity treatments. What made this work valuable was not just its thoroughness, but the fortitude of its authors to speak so candidly about this evidence.

The first thing they pointed out was that behavioral and dietary treatments for obesity continue to be advocated based on weak and often conflicting epidemiology data on health risks and despite overwhelming evidence from controlled clinical studies that weight loss programs are ineffective in producing lasting weight change. “Our failure to fully confront these issues [as healthcare professionals] has meant that, despite new knowledge, there has been no fundamental change in our practices,” they wrote.

Virtually any type of weight loss program is able to demonstrate moderate success at promoting “at least some short-term weight loss,” they found, but “there is virtually no evidence that clinically significant weight loss can be maintained over the long-term by the vast majority of people. Over and over again the initial encouraging findings are eroded with time.” Yet, these modest short-term results are used to recommend more aggressive interventions, they noted, under the belief that greater losses can be achieved, erroneously presuming that maintenance of weight loss is a realistic expectation and/or that there are no harmful consequences of weight loss or the inevitable regain.

The misconceptions of successful weight loss stem, in part, from a subtle problem “that occurs repeatedly: results are presented as positive when, in fact, all indications are that the long-term projections are quite poor.” It is exactly what Prometheus described as the “rationalization of failures as successes.”

Clinical trials dating back to 1970 have continued to show that the larger and faster the weight loss, the faster the regain, and the higher the follow-up weight. “It is only the rate of weight regain, not the fact of weight regain, that appears open to debate,” Garner and Wooley concluded.

They hoped that this evidence might provide some solace to all of those who’ve “failed” at dieting and believe it was their own fault due to a personal lack of will power.

Incorrectly identifying the cause leads to bad, risky solutions. Sadly, “harsh attitudes toward the obese depend on the assumption that they bring their condition on themselves through lack of will-power and self-control,” they said, and even respected researchers have suggested that social pressure against obesity needs to be increased. But, in fact, there is vast evidence for the heritability of obesity, estimated to be 88%, and a “tremendous body of research employing a great variety of methodologies that has failed to yield any meaningful or replicable differences in the caloric intake or eating patterns of the obese compared to the nonobese.”

Still, beliefs persist that obesity is due to irresponsible eating behaviors and that dietary management can be effective.

There is also tremendous individual variability in the degree of resistance to weight loss with caloric restriction, just as there is for weight gain with caloric increases. Yet how many fat people are accused of ‘lying’ about their food intakes when they fail to lose the ‘calculated’ amount of weight?

Perhaps one of the cruelist beliefs is that if fat people ate normally and “healthy” and just watched what they ate, they wouldn’t be fat. The evidence, however, consistently demonstrates that “successful weight loss and maintenance is not accomplished by ‘normalizing’ eating patterns’ [among the 'obese'] as has been implied in many treatment programs,” they said. That’s because the vast majority of fat people are already eating just like everyone else. Sadly, from young ages fat people are told they are overeating, though, by those who believe they must be overeating since they’re fat.

Any significant caloric restriction will result in initial weight loss for virtually all bodies. However, studies show remarkable similarity and the data is impressive, Garner and Wooley explained, indicating homeostatic metabolic adjustments to return body weights to their genetically-determined setpoint range as normal for each individual, and that this body weight defense occurs in 'obese' and 'nonobese'. Even short-term caloric restrictions result in rather dramatic metabolic adjustments (as much as a four-fold increase in metabolic efficiency) to preserve the body’s normal state. This phenomenon appears to explain why restrained eaters eating less actually weigh more than those with unrestrained eating styles. JFS readers have seen this time and again among populations, even over time among groups of women who started out the same weight. Many 'obese' individuals have spent much of their lives restricting their food intake with amazing resolve and discipline...and they are still fat.

With these biological forces at work, not surprisingly, weight loss studies see weight regain over time, even while calories continue to be restricted, and that to keep weight off or continue losing weight, increasingly severe caloric restrictions are required, incompatible with optimal nutritional health or wellbeing. [The ability for a naturally lean person to lose and gain 10-15 pounds comparatively easily, does not mean a naturally obese person can step and repeat that ten times to lose 100.] In fact, examining the rare 'obese' individuals who have been able to sustain weight loss over years, many times “their eating patterns are much more like those of individuals who would earn the diagnosis of anorexia nervosa than like those with truly ‘normal’ eating patterns,” Garner and Wooley found. Many are undereating and exercising obsessively and have made weight the focus of their lives.

It is often argued that obesity should be managed as a chronic disease with long-term calorie restrictions to control weight, said Garner and Wooley. But the “risks associated with subnormal intake must come under even greater scrutiny if such restriction is offered not as a short-term but as a long-term or even permanent solution,” they said.

Health is what matters. Garner and Wooley also looked at the health evidence, beginning with whether obesity is unhealthy. “Examination of the actual mortality data from many epidemiological studies makes it clear that across studies there is often no reliable pattern of association between premature death and relative weight,” they found. Studies chosen to emphasize associated health risks with obesity all too often don’t represent the preponderance of evidence that fails to support this contention, or to account for risks often due to confounding factors, including repeated weight loss interventions themselves. As they said:

Evidence that it is more dangerous to be thin than fat is either ignored or minimized in analyses that shape public policy toward weight loss. It is often suggested that risks may be permanently modified by weight loss without attention to the probable health risks associated with weight loss itself or with repeated diet failures.

While ‘statistically significant’ amounts of short-term weight loss may be demonstrated in weight loss studies, it is “generally too small to be of practical consequence.” There is no evidence that a 260-pound woman who loses 13 pounds (5% of her body weight) is any healthier or will live longer than had she maintained a steady weight:

There are few studies in the medical literature that indicate that mortality risk is actually reduced by weight loss and there are some that suggest that weight loss increases the risk of death.. and there is much evidence to suggest that maintenance of high but stable weight is safer than weight fluctuation, perhaps safer even than weight reduction.... [This] raises questions about the necessity and even the desirability of weight loss, especially in view of the likelihood of regain.

Even the act of dieting and weight loss is not benign and may have adverse effects including depression, anxiety, social withdrawal, eating disorders, food fears and personality changes. Dieting also leads to repeated cycles of weight loss and regain, which “may actually contribute to obesity by increasing metabolic efficiency,” they said. “We suggest that at the least, if weight loss is offered, it should be done with full disclosure of the lack of long-term efficacy and of the possible health risks.”

As they concluded:

It is difficult to find any scientific justification for the continued use of dietary treatments of obesity....Considering what is currently known about obesity and its treatment, we believe it remarkable that there have been so few calls for reexamination of the fundamental premises that form basic health care policy regarding weight loss....[A]t this time we can enhance the possibilities of meaningful scientific progress in other areas by reallocating resources currently invested in developing, applying, and studying dietary treatment that have little rational hope of success.

What is remarkable is that in the nearly two decades since this review, no evidence has come to light that negates its findings. In fact, the evidence continues to build. A review published this year examined the body of evidence to date and its findings were extraordinarily similar:

“Diets are not the answer”

Researchers at UCLA conducted a review of the evidence, including 14 long-term clinical trials lasting an average of 5 years, to assess the effectiveness of diets and exercise as a treatment for obesity. They began by evaluating the quality of the evidence and then examined long-term weight loss and health outcomes. “Short-term [temporary] weight loss is not a cure for obesity.”

Their review, led by Traci Mann, Ph.D., was published this past April. They prefaced by reporting that the body of evidence, and other renowned reviews of the scientific literature, on dieting agree on two conclusions:

1). Diets do lead to short-term weight loss, but...

2). loses are not maintained.

The longer the follow-up the more weight is regained. As Mann and colleagues concluded: “Even in the studies with the longest follow-up times (four or five years post-diet), the weight regain trajectories did not typically appear to level off. It is important for policymakers to remember that weight regain does not necessarily end when researchers stop following study participants.”

Every single one of the long-term diet trials they identified showed a weight regain trajectory, with one- to two-thirds of the participants’ weights already above baseline at 4-5 years follow-up.

In sum, across these studies, there is no strong evidence for the efficacy of diets in leading to long-term weight loss. In two of the studies, there was not a significant difference between the amount of weight loss maintained by participants assigned to the diet conditions and those assigned to the control conditions. In the three studies that did find significant differences, the differences were quite small. The amount of weight loss maintained in the diet conditions of these studies averaged 1.1 kg (2.4 lb).

It is hard to call these obesity treatments effective when participants maintain such a small weight loss. Clearly, these participants remain obese.

They, of course, note that “health benefits from even small weight losses are widely touted as reasons to diet.” However, health benefits from short-term studies of weight loss “do not address the question of what happens when the weight is regained.” They found no consistent evidence that diets resulted in meaningful improvements in health. In the three short-term studies showing health benefits, it could not be concluded that the effects were from dieting, or from exercise, sodium/alcohol reduction, (antihypertensive) medication use, or other interventions.

Moreover, the trials they reviewed did not find sustained health benefits when weight was regained. Of special concern to these authors was the popularity of ignoring the potential harm from dieting itself, as well as the weight regain and weight cycling seen among dieters. Many of those risks of harm from dieting and weight loss interventions have been reviewed here at JFS, including the National Institutes of Health expert review of nearly 50 years of evidence on voluntary weight loss, and which remains the most pivotal conference on the subject.

As the UCLA authors found:

There is evidence from large scale observational studies that weight cycling is linked to increased all-cause mortality and to increased mortality from cardiovascular disease. In addition, weight cycling is associated with increased risk for myocardial infarction, stroke, and diabetes, increased high density lipoprotein cholesterol, increased systolic and diastolic blood pressure, and even suppressed immune function.

These harmful effects remained in studies controlling for unintentional weight loss, such as from smoking or illness. Their conclusion:

In sum, the potential benefits of dieting on long-term weight outcomes are minimal, the potential benefits of dieting on long-term health outcomes are not clearly or consistently demonstrated, and the potential harms of weight cycling, although not definitively demonstrated, are a clear source of concern. The benefits of dieting are simply too small and the potential harms of dieting are too large for it to be recommended as a safe and effective treatment for obesity.

It appears that dieters who manage to sustain a weight loss are the rare exception rather than the rule. Dieters who gain back more weight than they lost may very well be the norm, rather than an unlucky minority. If Medicare is to fund an obesity treatment, it must lead to sustained improvements in weight and health for the majority of individuals. It seems clear to us that dieting does not.

Diets fail, not people

Another heavily-referenced review of the evidence on weight loss was written independently by Marion J. Franz, MS, RD, and published in a 2001 issue of Clinical Diabetes. Focusing our attention on the diet and weight loss parts of her review, compared to the analysis written for HealthPartners Health Behavior Group and Kaiser Permamente’s Care Management Institute [in Part One], finds the interpretations of the evidence in this paper remarkably different.

In her opening paragraph she came right out and said: “We do not yet know how to maintain weight loss over the long-term.” There is no evidence that any diet results in weight loss that’s maintained over the long-term.

“More than 54 million Americans are currently on a diet,” she wrote, “yet the prevalence of overweight and obesity continues to increase. If dieting worked, obesity should be decreasing or at least not increasing.” Many dieters succeed in taking weight off, but very few manage to keep it off over the long-term. Americans continue to seek a “magic bullet” that will help them lose weight, “unfortunately, health professionals also contribute to this phenomenon by constantly warning the public and their patients about the perils of being overweight,” she wrote.

Franz, like many obesity and eating disorder researchers, gives no credence to a national registry made up of the tiniest fraction of the dieting population who’ve self-reported a 30-pound weight loss in a year. A study of 784 participants, she reported, discovered that in trying to maintain their weight loss, they were obsessively exercising 1 1/2 hours a day and eating severely calorie restrictive diets of about 1,400 kcal/day. “In other words, their life is devoted to weight loss.” They generally exhibit anorectic behaviors, not healthy, normal eating.

As reviewed here, the first diet book based on the calorie theory was published in 1918 by a LA doctor, Lulu Hunt Peters. It recommended calorie reduction and increased exercise. Since then, about every possible way to lose weight has been proposed. There are some 7,500 diet books on the shelves today, each with it’s own claims about how to lose weight and each claiming their plan works.

“Many professionals claim to have the solution to weight loss,” she wrote. There are countless “authorities” out there who say they have the answer — and a book, product, or program to sell. But regardless of their popularity, “these solutions tend to be, at best, temporary... research reveals little long-term success.”

“We are reminded that popularity is not credibility,” she wrote.

Even “gold standard” behavioral weight-loss programs, she said, report that participants only keep off 60% of their initial weight loss one year later, with over a third having regained their lost weight; and “at 3 to 5 year follow-up, there was a gradual return to baseline weight.”

There is no diet that actually works long-term, despite lots of claims. In the short-term, however, any contrivance to reduce calories works. With only three macronutrients (carbs, protein and fat) to manipulate, she said, every permutation has been tried and “there are not many options left to sell a new diet book,” she wrote. Explaining further the various diet claims that have cycled in and out of favor over the years:

The current diet fad promises results with a high-protein, low-carbohydrate diet...Although the authors of the popular books all take a slightly different approach, the basic premises are fairly similar. Eating a high-carbohydrate diet, they claim, makes people “fat" because carbohydrate increases blood glucose levels, causing a greater release of insulin, and higher insulin levels cause carbohydrate to be stored easily as fat (in adipose cells). Eating a high-protein diet, the argument goes, leads to weight loss, decreased insulin levels, and improved glycemia. However, neither this nor the claim to “cure" insulin resistance—the oversecretion of insulin that proponents of these diets say causes the lipogenesis—with a low-carbohydrate, high-protein diet is supported by scientific evidence. Nor is there good evidence that insulin resistance from eating a diet rich in starchy foods and sugar is the cause of obesity....Another claim is that, if the right kinds of fat are eaten, individuals will not become fat...

An examination of the food intake of 9,372 Americans, for example, found weight loss is independent of diet composition. It was “energy restriction, not manipulation of macronutrients, associated with weight reduction in the short term.”

All diets work ... just long enough for those before-and-after photos.

Franz asked: “What can healthcare professionals do to help people be healthier, since it’s not possible to help them maintain weight loss?” She closed by answering: “Perhaps the most helpful thing we can do is to help individuals who struggle with their weight to like themselves. They are important people both for themselves and for those who they care about.”

Dieting and devoted efforts simply to change our outer appearance don’t define our health or our value as human beings. Tragically, so many have come to believe these do.

Returning to that original meta-analysis in the opening of this series, the evidence answered the authors’ question. What types of weight loss interventions offer ‘successful’ long-term outcomes?


© 2007 Sandy Szwarc

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December 28, 2007

Part One: What does the evidence reveal? Can diets work?

This two-part post is going to examine the evidence surrounding the question on everyone’s mind with the beginning of each new year: Do diets work?

It is widely believed they do and certainly the weight loss industry has been rigorously promoting that belief among both consumers and the medical community. The health dangers of obesity have been similarly promoted as being so great that weight loss is seen as imperative. What may be surprising, is that for some forty years, research has failed to support the effectiveness of weight loss interventions, namely diet and exercise, for the treatment of obesity. But each time a major review of the growing body of this evidence is released, it rarely reaches popular discourse. Belief in weight loss continues, while disregarding overwhelming evidence to the contrary.

We’ll begin with the latest meta-analysis of weight loss clinical trials recently published in the Journal of the American Dietetic Association. What makes this systematic review noteworthy and educational is that it provides a perfect illustration of why it’s important to look at the actual evidence and not shape our beliefs or make health decisions based on interpretations made for us in an abstract or by the media. The conclusions that are stated often bear little resemblance to the actual findings!

Weight management meta-analysis

The authors** of this meta-analysis were managers at HealthPartners Health Behavior Group and Kaiser Permamente’s Care Management Institute — who also financed the study — and it was led by Marion J. Franz, MS, RD, a respected diabetes educator and consultant with Nutrition Concepts by Franz, Inc. They said that their objective was to “determine what types of weight-loss interventions contribute to successful outcomes.”

Increasingly more insurer performance measures, disease case management by insurers, and clinical guidelines recommend weight loss interventions.

The question of which weight loss interventions are effective and what are realistic long-term outcomes are important for health professionals counseling patients, as well as for the general public, wrote the authors.

So, they stated, they reviewed all weight loss interventions reported in the medical literature — diet alone, diet and exercise, exercise alone, meal replacements, very-low-energy diets, and weight-loss medications (orlistat and sibutramine) — that used weight loss as the primary outcome and had at least 12 months of follow-up in order “to determine treatment interventions that contribute to sustained weight loss maintenance.”

Searching PubMed, they identified 80 studies that met their criteria. Given the many more weight loss trials that have been conducted and are known to obesity researchers, a closer look finds that only studies published from January 1997 through August 2004 were included in this meta-analysis. They pooled the data for each type of intervention. The main caution they noted was that most of the studies reported weight-loss outcomes based on the participants who completed the studies and attrition (drop-out) rates were exceedingly high, averaging 31%.

The reported findings. Very-low-energy diet studies resulted in a dramatic weight loss followed by rapid and substantial weight regain, they reported. Exercise alone or just providing weight loss advice, regardless of the method or intensity, did not result in successful weight loss. Interventions incorporating reduced caloric intakes “seem to produce the most encouraging short-term results,” they concluded, and were associated with “moderate weight loss at 6 months. Although there is some regain of weight, weight loss can be maintained.”

Overall, they said, “in studies extending to 48 months, an average 3 to 6 kg of weight loss was maintained [6 -13 pounds after 4 years], with none of the groups experiencing weight regain to baseline.”

A closer look, however, shows that exceedingly few studies included in their review were long-term weight loss studies (2 or more years follow-up) or able to demonstrate any maintenance of weight loss — the definition of success. In fact, only three studies in their entire review extended to 4 years follow-up to support their conclusions:

· Only one diet study (Manning et al. 1998) was long-term, which had a 4 year follow-up after a 26 week intervention period. It compared diet to dexfenfluramine among 132 diabetics. With an unknown number completing the diet arm, the average weight loss was 1.7 kg at the 4-year follow-up, but there was a steady regain trajectory which was not followed to its conclusion.

· There was only one diet and exercise trial that was long-term included in this review, (DPP 2002) with a follow-up of 4 years. It was a 24 week intervention on diabetics comparing weight loss with metformin. But it also had a regain trajectory, showing a 4 kg average weight loss at the 4-year follow-up mark.

· None of the exercise or meal replacement trials were long-term studies (at most 1.5 and 1 year, respectively).

· Only one very low calorie diet (VLCD) was long-term (>2 years follow-up). In this study, only 25 people had completed it and they were also on a regain trajectory. Overall, the VLCD studies showed regain trajectories, with the longer the follow-up the greater the regain, (averaging 80-90% regain after 2 years).

It’s not known what any of these trajectories would have finally shown had the studies been continued, rather than discontinued before the weight rebounds stopped. Even so, few would likely argue that these demonstrate ‘weight maintenance.’

Conclusions. The authors concluded:

Despite the limitations, this systematic review provides a set of results that represents the longest-term studies of weight loss and maintenance available in the literature and places them in a context that is meaningful to practitioners....At approximately 6 months, weight loss begins to plateau across nearly all interventions, but with continued professional support such as was provided in the clinical trials, weight loss can be maintained.

The wording appears to suggest that this paper provides evidence that healthcare providers have the ability to ensure long-term weight loss maintenance in their patients. But it didn’t. Given that insurance plans, however, might use this conclusion as evidence to justify P4P (pay-forperformance) measures for doctors, both doctors and laypeople have an interest in learning what is known about the effectiveness of counseling by doctors and long-term weight loss maintenance.

P4P: Doctors’ obligatory roles as weight loss counselors. First, is there any evidence that dietary and lifestyle counseling — increasingly required of doctors by insurers — is effective for long-term weight loss of their ‘overweight’ and ‘obese’ patients, or even for those with specific life-threatening chronic diseases?

· No. Researchers at Tufts England Medical Center in Boston, Massachusetts, for example, examined 46 clinical trials of dietary counseling for weight loss, involving nearly 6,400 dieters. Regardless of the programs — the intensity of the interventions, number and frequency of support meetings, individual or group counseling, caloric or other dietary restrictions, inclusion of exercise, use of electronic media such as the internet, or level of participation — all produced an average weight loss of about 6 percent during the first year..... But a steady regain every month after that. By the end of five years, all participants had fully regained their weight.

· No. The scientific reviews of the evidence on dietary counseling conducted by the U.S. Preventive Services Task Force in 1996 and 2003 concluded there is insufficient evidence to recommend routine counseling by healthcare professionals to promote a healthy diet in adults. Even the evidence for intense interventions among highly-motivated high-risk groups still demonstrated only modest short-term changes, with no information on actual health benefits and insufficient evidence to recommend widespread dietary counseling.

· No. The USPSTF could not determine the balance of benefits and potential harms of counseling with behavioral interventions to promote weight loss and concluded that the evidence is insufficient to recommend for or against the use of counseling of any intensity and behavioral interventions to promote sustained weight loss in overweight adults.

While weight loss was the primary outcome measure for a successful weight loss intervention, even these authors recognized that effectiveness cannot be determined or claimed unless weight loss is maintained. Obesity researchers and the research universally define weight loss success as being weight loss maintained for at least five years.

· The expert panel of the FTC reviewed the evidence for their 2003 report and found that one of the top bogus weight-loss claims was for permanent weight loss. According to Dr. Susan Yanovski: “Unfortunately, as we all know, weight regain after weight loss is the rule rather than the exception...There are no known supplements, devices, programs that give you a permanent alteration in your body’s metabolism, and there is no way that lost weight will be maintained.” In their scientific analysis, the expert committee said that according to the National Academy of Science, Food and Nutrition Board, “many programs and services exist to help individuals achieve weight control. But the limited studies paint a grim picture: those who complete weight-loss programs lose approximately 10 percent of their body weight only to regain two-thirds of it back within 1 year and almost all of it back within 5 years.”

· In fact, the FTC charged five of the largest commercial diet companies (Weight Watchers, Jenny Craig, Diet Center, Nutri/System and Physicians Weight Loss Center with, among other things, deceptive advertising for making unsubstantiated claims about weight loss and long-term maintenance. [Read what happened here.]

· Remember that $2 million clinical trial conducted by Stanford University researchers who tested the four top commercial diets? Among 311 healthy women and after one year of dieting, all of the diets resulted in modest weight loss at best, and all dieters were already steadily rebounding, with the biggest losers rebounding the most dramatically. The participants were still eating notably fewer calories (359 to 500 kcal/day less), even while they were regaining the weight lost. This study, however, was too short to be able to demonstrate long-term effectiveness. It’s like other studies of commercial diets: none have reported 5-year results.

As we consider this HealthPartners-Kaiser meta-analysis, the most important question to ask ourselves is: Did these researchers ask the right question?

Is healthcare about appearances and helping people lose weight to look slim — let alone get into a smaller dress/pant size for a brief time — or is it about improving health and longevity? If medicine is about health, then the evidence of health risks and benefits of obesity and weight loss are the imperative considerations. Without that evidence, weight is nothing more than a false surrogate endpoint.

In Part Two, we’ll look at three reviews that did examine that evidence: one of the most renowned and comprehensive review completed in 1991 by professors and experts on behavioral treatments for obesity and eating disorders; the recent done this spring by researchers at the University of California, Los Angeles; and one by the lead author, Franz, herself.

© 2007 Sandy Szwarc

* N. P. Pronk is executive director, HealthPartners Health Behavior Group

A. L. Crain is a statistician at HealthPartners Research Foundation

J. VanWormer is a program evaluation consultant at HealthPartners Health Behavior Group

J. L. Boucher was director, Health Programs and Performance Measurement, HealthPartners Health Behavior Group during this study (currently, director of education at Minneapolis Heart Institute Foundation)

T. Histon is director of weight management initiative at Kaiser Permanente’s Care Management Institute

W. Caplan is director of clinical development at Kaiser Permanente’s Care Management Institute

J. D. Bowman is manager of knowledge and information at A. Kaiser Permanente Innovation

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December 27, 2007

Free isn't always a benefit: free bariatric surgery for kids

We now have an idea of what the “or else” might be for fat children in the UK who fail to lose weight. Under a new proposal for the clinical management of fat children under NICE (National Institute for Health and Clinical Excellence) guidelines, bariatric surgery would be provided for free in Norfolk...to children.

According to the evening news:

Children at N&N to get stomachs stapled

Children in Norfolk who are overweight or obese could for the first time be offered surgery under radical plans to stem the growing problem. More than a quarter of children living in the county are classed as overweight or obese, but if they want to lose weight through surgery they cannot do so for free in Norfolk.... the Norfolk and Norwich University Hospital is to submit a plan to county health chiefs to carry out surgery on the most severe cases, although only involving children. A spokeswoman for the N&N said: “The Jenny Lind Children's Department at the N&N is in the process of preparing a business case to provide obesity surgery for children only. “We are putting the case forward because of a rise in childhood obesity and illnesses associated with it....

Dr Michael Rhodes, a Norfolk surgeon who currently carries out operations on a private basis and would be one of the surgeons who operate on the youngsters next year, said: “I am very pleased that youngsters will soon be offered gastric banding. Of course this will only be in extreme cases when everything has been tried and the child just cannot lose weight....

A staggering 15,700 children up to the age of 15 are overweight in Norfolk and 5,700 obese. Last month health experts warned that despite prolonged efforts to promote healthy eating and exercise in schools the number of overweight children is not falling....

Nothing better exemplifies the importance of sound, science-based information and government programs accurately defining a ‘problem’, its causes and interventions, for which actual health benefits have been proven to outweigh the risks.

The clinical practice guidelines issued by NICE** last December to be followed by British doctors under the National Health Services (NHS), included “Obesity: prevention, identification, assessment and management of overweight and obesity in adults and children.” Under these “evidence-based” guidelines, prevention and management are directed towards getting everyone to a “healthy weight,” as defined as a “BMI of 18.5 to 24.9,” primarily through diet and exercise interventions and healthy lifestyle changes. The NICE guidelines also include sweeping recommendations outlining actions that should be taken by local authorities, employers, town planners, communities, childcare providers and schools to stop the epidemic of obesity.

The current NICE obesity guidelines for children have been reviewed here previously, but briefly include:

· assessment of children’s BMIs, family lifestyles and environmental/social factors affecting diet and exercise;

· children and families are to be instructed on the health dangers of being overweight, treatment options and behavioral modification techniques;

· families are to be counseled and expected to eat regular meals together without television, including breakfast, encourage active play and discourage sedentary activities in children;

· results of the discussions should be documented and a copy of the agreed goals and actions are to be kept in the child’s medical records;

· referral of overweight children to weight loss specialists and weight loss programs that focus on behavioral changes to reduce calories and increase physical activity;

· overweight children may need to do more than an hour of exercise a day and encouraged into structured activities;

· extensive work-ups for overweight children to identify “comorbidities” (cholesterol, blood pressure, insulin and glucose, liver and endocrine function, etc.);

· for those who fail to meet their weight loss target weight, orlistat or sibutramine is recommended for children 12 years and older with comorbidities, and may be used indefinitely to maintain weight loss; and....

· “Bariatric surgery is recommended as an option for adults and children after all appropriate non-surgical measures have been tried but have failed to achieve or maintain adequate, clinically beneficial weight loss for at least 6 months.” However, “surgical intervention is not generally recommended in children or young people [section]. Bariatric surgery may be considered for young people only in exceptional circumstances, and if they have achieved or nearly achieved physiological maturity [section].” These restrictions would be removed under this new proposal.

As researchers continue to point out, simply calling guidelines evidence-based does not make them so. British researchers, for example, who conducted a careful and extensive review of the clinical evidence on the government’s initiatives for childhood obesity, found no evidence for the effectiveness of monitoring or screening children to prevent or reduce obesity. Disturbingly lacking were studies that credibly examined the potential harm of such programs. Worse, no study identified an effective weight reduction or preventive intervention. Not surprisingly given what is known about childhood obesity, every childhood obesity initiative, even with the most intensive focus on healthy lifestyles and balancing "calories in-calories out", has proven ineffective long-term.

There’s even less evidence for long-term health benefits of bariatric surgeries or that they outweigh risks for children. And there is absolutely no evidence that bariatric surgery is an emergency procedure and that without it fat children will die before they reach the age of consenting adults. What is the “or else” for parents who don’t want their eligible children to undergo surgery or who feel the risks and long-term nutrition-related consequences are not in their children’s best interests? Will their children be removed from the home and forced into state care if they don’t lose weight, too?

** The NICE obesity guidelines were created by a long list of public health officials working with about 250 stakeholder organizations, which included all of the major pharmaceutical companies, Atkins Nutritional, Inc., obesity and bariatric trade associations, the International Obesity Taskforce of the International Association for the Study of Obesity, Slim-Fast Foods Ltd, Weight Watchers UK, etc.

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December 26, 2007

Action words: One word can change everything

In today’s soundbyte world, blurbs and headlines are often shaved of their accuracy in an attempt to make a health story sound splashier and action-packed. The story may be more likely to grab our attention, but all too often it also reports what the original study did not, and could not, conclude.

Health News Review has published a simple and very helpful piece focused on one aspect of this problem: understanding causal language. Directing their concerns to health journalists writing stories and headlines, they caution against changing adjectives (“lower risk”) to verbs (“lowered” the risk) when reporting on epidemiological studies. Why? That simple switch changes the meaning: from a correlation to imply a causation. Nouns can suffer similar degradations during wordsmithing.

Their explanation of the types of study designs and the limitations of each may be helpful to journalists, but also for readers to help recognize when news reports have stepped beyond credibility. Does eating fish preserve your eyesight or cut your risk of dying of a heart attack? Does drinking coffee lower your risks for diabetes? Can aspirin prevent cancers? Does drinking alcohol increase your risk for breast cancer? In actuality, it was not even possible for the studies that examined these correlations to answer any of these questions. But how many news reports made that clear?

This valuable article is here, and begins:

Publisher's Corner

A health writer’s first attempt at expressing results from a new observational study read, “Frequent fish consumption was associated with a 50% reduction in the relative risk of dying from a heart attack.” Her editor’s reaction? Slash. Too wordy, too passive. The editor’s rewrite? “Women who ate fish five times a week cut their risk of dying later from a heart attack by half.” This edit seems fair enough – or is it? The change did streamline the message, but with a not-so-obvious, unintended cost to the meaning.....

The authors go on to describe epidemiological studies and randomized trials, highlighting one of the most crucial and most misunderstood differences:

Epidemiologic – or observational – studies examine the association between what’s known in epidemiologic jargon as an exposure (e.g., a food, something in the environment, or a behavior) and an outcome (often a disease or death). Because of all the other exposures occurring simultaneously in the complex lives of free-living humans that can never be completely accounted for, such studies cannot provide evidence of cause and effect; they can only provide evidence of some relationship that a stronger design could explore further..... The only study design involving humans that does rise to the level of demonstrating cause and effect is a randomized trial.... Because observational studies are not randomized, they cannot control for all of the other inevitable, often unmeasurable, exposures that may actually explain results. Thus, any link between cause and effect in observational studies is speculative at best.

During the writing, editing and headline composing are all opportunities for imprecise wordsmithing that can imply causation from correlations, they caution. Other sources of such mistakes for health journalists, they said, are borrowing the language found in press releases or as expressed by some researchers when describing the results of epidemiological studies. These errors can mislead readers into believing that a cause or treatment has been found, to overestimate the value of the study findings, or even to make life decisions that the evidence doesn’t support.

However, to be fair to the best writers, and as a caveat to readers tempted to skim headlines for the gist of the health news, very few writers write the headlines that accompany their articles or even get to see them before they go to press. Headlines are often written by copy writers, who you can be pretty sure don’t have science or medical degrees, nor read the study.

As the authors noted, it’s important to pay attention to language and the subtle ways that word choices can imply cause-and-effect relationships when a study design does not support such conclusions. That’s advice we all can use!

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Answer: horrifying

Please read this powerful article. A teacher not only taught her elementary school class to sing this song, she was apparently so proud of it that she created a U-tube video.

Can you imagine what it must be like for the fat children listening to this concert or for those in the class? Has the war on childhood obesity reached the point where role modeling taunts are seen as acceptable teaching moments? A series of posts at JFS looked at the harm and hurt from the harrassment fat children experience in school, and readers were urged to read their painful stories growing up.

As today’s writer said:

[I]f you’re tempted to see children teasing about weight, or a music teacher implicitly encouraging it as adorable and funny, the web site I Was a Fat Kid...This is my Story should be a cold splash of water on the face....what’s also clear from reading these stories is that for many of these kids, the victimization they endure in school leads to profound trauma and scarring. Suicide attempts, eating disorders, rage and depression come up a lot...

Most of the perpetrators of course are just children, but one of the pervasive themes in these stories is how so many of these kids felt that the adults around them (particularly teachers) were either willfully ignorant of or complicit in the abuse, with some either subtly or overtly encouraging it.

Or that’s how the children saw it anyway. It’s impossible to know, really, from a child’s eye view what was going on in the minds of the adults around them. Was the teacher who weighed all the students in front of each other ignorant of the effect this would have on the fat children? Or just didn’t think it was very important? Or just didn’t think.

I guess I have the same question about teachers who would teach children this song. It’s only funny if you don’t think.

The entire article and personal comments are valuable reading and remind us all … to think.

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December 25, 2007

Inquiring minds want to know: when are food and health claims real?

Is healthcare always based on science or are there times when our care and medical advice is founded on myths, beliefs, tradition or anecdotes? In the current issue of the British Medical Journal, two pediatricians took a lighthearted look at seven medical myths they said they’d heard repeated among doctors or in the popular media. The myths, they said, “appear to be ingrained in the popular imagination, including that of physicians.” Regrettably, with their rather unscientific selection process and choice of fairly trivial topics, the serious point they were trying to make was lost, in the media and medical commentary. Here it is, as they wrote:

Physicians understand that practicing good medicine requires the constant acquisition of new knowledge, though they often assume their existing medical beliefs do not need re-examination. The medical myths we give here are a light hearted reminder that we can be wrong and need to question what other falsehoods we unwittingly propagate as we practice medicine....

Physicians would do well to understand the evidence supporting their medical decision making. They should at least recognise when their practice is based on tradition, anecdote, or art. While belief in the described myths is unlikely to cause harm, recommending medical treatment for which there is little evidence certainly can. Speaking from a position of authority, as physicians do, requires constant evaluation of the validity of our knowledge.

It is extremely difficult, however, to bring oneself to even consider or accept evidence contrary to everything one has come to believe. Once a belief has taken hold and becomes popular, it’s rarely questioned. The need to do so is inconceivable.

No one, including healthcare professionals, intentionally sets out to believe things known to be false. Most people truly believe what they’ve come to know. But, as the Critical Thinking Lessons explained, in order to avoid falling victim to unsound claims requires understanding the process of critical thinking and how to circumvent the fallacies of logic that can beset anyone, and actively working to avoid the most fundamental error in thinking, the confirmation bias. And that’s harder than it sounds:

[W]e have an automatic tendency to pay attention to or seek out information that is in agreement with (confirms) our preconceptions, and to ignore, distort or avoid information that contradicts (disconfirms) our preconceptions, a tendency that is called the confirmation bias. The confirmation bias serves to maintain and strengthen the beliefs that we already hold by causing us to automatically (that is, without being aware that we are doing so) perceive and remember experiences that confirm these beliefs, and to ignore or reinterpret those that disconfirm them. Because we tend to seek out only confirming evidence, our beliefs over time become so well confirmed in our minds that we come to think of them as “obviously true." In order to avoid the confirmation bias, we must force ourselves to look for evidence that disconfirms our beliefs.

As the confirmation bias takes hold [discussed here], people become more and more certain that what they believe is right. Simultaneously, according to Dr. Ben Goldacre, a London physician, people also become increasingly more resistant to evidence which counters their beliefs. “When you point out a problem with the evidence,” he wrote, “people don't engage with you about it, or read and reference your work.” They react quite negatively. As he illustrated with homeopathy, this vehement resistance isn’t actually about the science or a productive debate of the evidence. It is not scientists disagreeing about the science, as some might try to claim. Even when carefully conducted scientific studies have proven something not to work, he explained, its proponents cannot see or accept the evidence.

A study published in this month’s Journal of the American Medical Association highlighted how common it is for claims to persist and even continue to be supported in certain scientific circles and in the medical literature long after they have been disproven. Changing established medical and nutritional beliefs is not easy, nor is it just a matter of presenting the evidence. The researchers, led by Dr. Athina Tatsioni, M.D., at Tufts University School of Medicine in Boston, traced nutritional claims (antioxidants beta-carotene for prevention of cancer, vitamin E to prevent cardiovascular disease in women, and estrogen for the prevention of dementia) that had strong contradictory evidence from large, high-quality, randomized clinical trials. They examined the acceptance of this evidence in the medical literature compared with the persistence of popular beliefs formed from earlier studies based largely on associations:

The persistent favorable stance toward the contradicted interventions was particularly prominent in articles published in specialty journals of both clinical and basic science disciplines. Specialist articles apparently continued to use references to the highly cited observational studies to support their own lines of research. The presence of refuting data were not mentioned in many articles. Other articles did report data with contrary results, but they raised also a wide array of counterarguments to support the observational claim.

As is well-recognized, the researchers noted that positive results from randomized clinical trials were the ones most published in specialty journals and citations were biased towards positive findings. The belief bias of people, they said, regardless of the topic, also influences the interpretation of scientific results. When studies offered contradictory findings, the original belief based on observational studies “was defended at all cost.”

The defense of the observational associations was persistent, despite the availability of very strong contradicting randomized evidence on the same topic. Thus, one wonders whether any contradicted associations may ever be entirely abandoned, if such strong randomized evidence is not considered as much stronger evidence on the topic.

This is important because, as we know, it’s those null and negative findings which are vital to the progress of science. It is the ability of experiments to disprove an hypothesis in carefully-designed studies that sets science apart from pseudoscience. This is the source of Albert Einstein’s famous saying: “No amount of experimentation can ever prove me right; a single experiment can prove me wrong.”

The Tufts researchers showed that randomized trials disproving beliefs derived from observational studies eventually results in less frequent citations of those epidemiological studies. But it occurs with “considerable delay and a considerable segment of the literature continues to cite the contradicted articles long after the contradiction.” Even fifteen years later, the claims and disproven studies continue to predominate the literature. And “the articles that cited these observational studies continued to be predominantly favorable.”

The delay can mean wasted healthcare resources, failure to pursue effective modalities and potential harm.

They concluded by suggesting that better communication of evidence-based clinical science might improve this situation and “lead to more rational and concerted translational efforts in basic, preclinical, and clinical research.” But simply communicating the evidence circles back to the issue of confirmational bias and missing critical thinking skills. Several have voiced concerns that even medical school curriculums don’t provide these essential skills for young doctors. Dr. R. W. Donnell, a hospitalist in Northwest Arkansas, for example, has written extensively on the inundation of alternative beliefs and modalities in American medical schools and the medical profession as a result. Similar concerns have been raised concerning nursing.

Researchers at Georgetown University School of Medicine in Washington, DC, for example, surveyed 265 medical students and found 91% embraced alternative modalities as beneficial to Western medicine; most wanted it incorporated in their medical training; and most planned to endorse, refer patients or provide alternative modalities in their future practices.

Last summer, Prometheus wrote a valuable and germane article on how misconceptions about how science works can lead to false yet “generally accepted theories of reality.” These aren't just seen behind established medical myths, but also the myths popular throughout our culture and mainstream media. They also help to explain why the validity of those beliefs aren’t often questioned and re-evaluated.

To illustrate his point, he used the beliefs in an epidemic of autism [previously examined], writing:

One of the most commonly repeated misconceptions is that scientific ‘facts’ (what scientists refer to as ‘generally accepted theories of reality’) are determined by popular vote.... Unfortunately for them, reality has shown itself supremely indifferent to majority rule... So, even if seven thousand people think that Andy Wakefield’s thoroughly disproven hypothesis about measles vaccine causing autism is true, that will have no impact on the ability of the vaccine strain of measles to cause autism.

The sad fact is that the purpose of science is to discover the underlying realities of nature, not to confirm our most cherished hypotheses. When people...set out to prove themselves right, they often overlook the data that show they are wrong.

Considering another example, the perceived epidemic of obesity, even if innumerable people believe the thoroughly disproven hypothesis about overeating or bad foods and sedentary behavior as causing obesity, it will have no impact on the ability of diet and exercise or a healthy lifestyle to “cure” or prevent obesity. Hence, the consistent failure of diets and exercise interventions to work long-term, with rare exceptions, after a century of such efforts.

Prometheus went on to explain another popular misconception:

Another popular concept is that scientific reality can be legislated. This has been tried a number of times previously and has a dismal history... “Science by decree” appeals to those who are absolutely convinced that there is no possibility that they might be wrong....But what happens when it becomes apparent that the legislated “science” is in error? What will the legislators say to those who entreated them to make the law in the first place? How receptive will they be to another group of parents who come to them, saying “Well, it turns out that vaccines weren’t the cause of autism and we need a bunch of money to research the real cause.” Do you think that any law maker is going to want to bring that before their peers?

I think that everybody knows that if the various...groups had the data, they wouldn’t need to do an “end run” around science (and, curiously, the courts) to the legislature. What they are saying, in essence, is: “We can’t convince scientists, we can’t convince the courts and we can’t even convince a majority of parents with our data, so we’re asking you to force everybody to say that we’re right.”

Similarly, the "Healthy Lifestyles and Prevention America Act" and no amount of legislated healthy behaviors are working on obesity, either.

So why do so many beliefs persist, even after the soundest science has long ago disproven them? And why are they so compelling? Whether it be promises of long-term weight loss or cures for autism, the beliefs are accepted, in large part, because they sell hope. As Prometheus commented about autism:

[T]he "experts"...are accepted because they offer hope. The sad part is that they are — so far as science can determine — offering false hope. I know that some people feel that it is a mercy to offer hope, even when it is false. However, I am firm in my belief that, ultimately, offering false hope is more destructive than offering the truth — that there is nothing that is known to help.

I think that it is perfectly reasonable for physicians to tell parents that there are some “treatments" that other parents have tried and that they report some success, but I think that it is imperative that they be absolutely clear that none of these treatments has been shown to work. Much of the problem is that the “practitioners" who advocate these “therapies" are so divorced from critical thinking that they fail evaluate their own results. I have heard them rationalize their failures into successes ... They are, as the old saw goes, “Often in error but never in doubt."

© 2007 Sandy Szwarc

Up next, the newest review of the evidence on diets and weight loss interventions that exemplifies what Prometheus described as rationalizing failures into successes.

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