In 2002, Dr. William Klish of Texas Children’s Hospital told the Houston Chronicle: “If we don’t get this epidemic [of childhood obesity] in check, for the first time in a century children will be looking forward to a shorter life expectancy than their parents.” Since then, Klish’s statement has entered the lexicon of obesity scaremongers, making its way into countless articles, editorials, and even Congressional testimony — all without so much as a shred of credible research to back it up. Klish himself has told the Center for Consumer Freedom that while he is the originator of this pessimistic prognostication, his claim does not come from “evidence-based research.” Rather, he explained, “It’s based on intuition.”

Today, more than three years after Dr. Klish first suggested the idea, the New England Journal of Medicine (NEJM) released a deeply flawed study that seeks to justify Klish’s assertion. It claims that because of obesity the “youth of today may, on average, live less healthy and possibly even shorter lives than their parents.” But like Klish, Dr. S. Jay Olshansky and his team of co-authors admit that their dire prediction relies on their “collective judgment” rather than empirical, scientific evidence.

This study is just half a step removed from science fiction,” we told USA Today. “It uses discredited methodology, and it makes dire warnings that are not supported by its own data.”

“The Olshansky piece is seriously flawed,” Dr. James Vaupel, director of the Max Planck Institute for Demographic Research in Germany explained to us in an e-mail last week. “His perspective is that of an advocate making a case rather than a scientist evaluating the body of conflicting evidence.”

Vaupel isn’t alone in questioning Olshansky’s prediction. Dr. Robert N. Anderson, the lead author of the CDC’s National Vital Statistics Report on life expectancy, explained that he was extremely skeptical of Klish and Olshansky’s claim about obesity’s effect on life expectancy. He told us: “I really would be shocked if we got a generation down the road and life expectancy was lower than the previous generation. I really would be surprised … We’ve never seen anything like that. Life expectancy has gone up pretty steadily.”

Even noted obesity-scaremonger JoAnn Manson explained to the Associated Press, “the calculations that were made may not be perfect.

So what went wrong with the study? Although Olshansky purports to show that if the entire nation were an “ideal” weight we might live, on average, a few months longer, he provides no empirical research to back up his foreboding forecast about life expectancy actually decreasing. Instead, without so much as a footnote (except to their own work), he and his co-authors muse that the “trends” in the data suggest the possibility of life expectancy declining.

The study essentially ignores the influence of medical progress (e.g., discovering new vaccines and developing new disease-fighting procedures) in increasing life expectancy. Despite the enormous gains we’ve seen (more than six years since 1970), Olshansky and his co-authors write: “We believe that potential forms of technology do not justify developing or revising forecasts for life expectancy.” At the same time, they offer a few guesses about future trends in obesity, which supposedly support their dire warnings.

The Authors

No one familiar with the study’s authors would be surprised by their outrageous conclusions. Olshansky himself tops the list of the nation’s life-expectancy naysayers. Dr. Richard Suzman, associate director of the Behavioral and Social Research Program at the National Institute on Aging, once told Knight Ridder newswire: “Olshansky’s position [on decreasing life expectancy] is a minority perspective in demography.” Dr. Vaupel added, “There is a small chance — less than one in 100 — that Olshansky’s prediction of declining life expectancy might possibly prove correct.”

Olshansky co-authored the study with long-time obesity scaremonger David Ludwig, who hysterically compared childhood obesity to a “massive tsunami heading for the United States.” And as we explained to the Associated Press, co-author David Allison presents a number of troubling financial conflicts of interest — so many, in fact, that NEJM published a three page financial disclosure, listing more than 100 organizations (mostly weight-loss companies) from which he’s received money.

Allison authored a 1999 study blaming obesity for 300,000 deaths a year in America. The study, which was printed in JAMA, included the disclosure that Allison “has received grants, honoraria, monetary and product donations, was a consultant to, and has contracts or other commitments with numerous organizations involving weight control products and services.” An internal review committee at the Centers for Disease Control and Prevention has called his method for counting obesity attributable deaths “fundamentally” flawed. Despite the controversy surrounding Allison’s method, the authors of the NEJM study explain that because they only wanted “plausible estimates rather than precise numbers,” they chose to rely on Allison’s “simpler approach.” Not surprisingly, that “simpler approach” tends to exaggerate the problem.

From Science to Activism

Earlier this year, well before Olshansky’s article was to be published, we set out to determine the veracity of Dr. Klish’s initial claim about this generation of children living shorter lifespans than their parents. At that point, dozens of activists, researchers, and even respected public health officials had already taken Klish’s statement and run with it. They include Yale University professor Kelly Brownell, Physicians Committee for Responsible Medicine ally Dean Ornish, and some of the nation’s most respected health officials. In March of 2004, the Surgeon General told Congress:

Because of the increasing rates of obesity, unhealthy eating habits, and physical inactivity, we may see the first generation that will be less healthy and have a shorter life expectancy than their parents.

We contacted the Surgeon General’s office to inquire about the source of his doom-and-gloom statement. After all, it’s hard to believe that the nation’s top doctor would offer testimony before the United States Congress based merely on one doctor’s intuitive guess.

Carmona’s spokesman told us: “I don’t think that there is a study somewhere that life expectancy will shrink if we don’t do this. I think that it was just based on some literature that he had read … It was an amalgamation of the information he has been reading.”

Considering the Centers for Disease Control and Prevention’s (CDC) recent admission that its study on the number of deaths attributed to obesity grossly overestimated the problem, Carmona’s reliance on Klish’s “intuitive” guess seems, sadly, par for the course. This fall, the Department of Agriculture’s Undersecretary for Food, Nutrition, and Consumer Services told a Congressional subcommittee that “this may be the first generation of children not to live as long as their parents as a direct result of [childhood obesity].” His spokesman did not return follow-up calls after telling us in an initial conversation that he could not find any research to substantiate this claim.

Last summer, when TIME magazine and ABC News co-hosted a highly publicized and decidedly one-sided conference on obesity, the head food cop at the Robert Wood Johnson Foundation (RWJF) began the proceedings by saying: “If we don’t do something to reverse these trends, we will raise the first generation of Americans to live sicker and die younger than their parents.” A similar statement showed up in a policy proposal by the RWJF-funded Trust for America’s Health, titled “F as in Fat: How Obesity Policies Are Failing in America.” The first page of the proposal reports that “many experts … predict that the nation’s younger generation may be the first in American history to live sicker and shorter lives than their parents.” We contacted the Trust to see if they could name their “many experts.” Predictably, the group cited three: the Surgeon General, Klish, and “someone” at the CDC. (We contacted the CDC, and after a day of searching all they could produce was an editorial quoting a doctor affiliated with the agency’s VERB program.)

The Trust’s spokesperson added: “The reason that we use these kinds of facts is because it does draw press attention to the problem … A lot of policy organizations [do not rely on scientific literature], because they draw attention, quite honestly.”

Dean Ornish offered by email a similar explanation for his, and others, regurgitation of Klish and Olshansky’s false claim: “I think this gets quoted because it gets people’s attention to what is a real problem that only seems to be getting worse. To that extent, it can be useful.”

All told, we contacted more than a dozen people who had stated publicly that childhood obesity would make this the first generation of children to have a shorter lifespan than their parents. And time after time, they failed to provide us with even a single source to back up their claim. The only exception was Yale Professor David Katz, who suggested two studies (they can be found here and here) that supposedly prove his point. Of course, they don’t.

Although both studies indicate that the severely obese may suffer health complications due in part to their weight, neither comes close to suggesting that obesity could change the CDC’s estimate that people born in 2004 are expected to live more than six years longer than their parents. And neither does this week’s study from Olshansky, Ludwig, Allison, and their colleagues.