What is the #1 killer of Americans? Evening News watchers from the late-1990s might have guessed breast cancer until around 1999 or 2000 when the grim reaper wielded cigarette smoke. This year, death is, at least, a bit more palatable – fat. Over the last two years, the major media has cited the fat stat nearly 2,000 times – claiming that being overweight claims 300,000 American lives each year.
Turns out, they might be wrong.
America, we are told, is on the verge of eating itself to death. The core case is a strong, predictable relationship between increasing weight and increasing mortality. That, after all, is what most people assume when they read that medical and public health authorities have determined a BMI of 25 or above is hazardous to a person's health.
According to a frustrated professor who went back to the source, the actual science suggests otherwise:
A 1996 project undertaken by scientists at the National Center for Health Statistics and Cornell University analyzed the data from dozens of previous studies, involving a total of more than 600,000 subjects with up to a 30-year follow-up. Among non-smoking white men, the lowest mortality rate was found among those with a BMI between 23 and 29, which means that a large majority of the men who lived longest were "overweight" according to government guidelines. The mortality rate for white men in the supposedly ideal range of 19 to 21 was the same as that for those in the 29 to 31 range (most of whom would be defined now as "obese"). In regard to non-smoking white women, the study's conclusions were even more striking: the BMI range correlating with the lowest mortality rate was extremely broad, from around 18 to 32, meaning a woman of average height could weigh anywhere within an 80-pound range without seeing any statistically significant change in her risk of premature death.
Annual Deaths Attributable To Obesity In The United States, which appeared in the Journal Of The American Medical Association (Jama) in 1999, is the source for the endlessly repeated statistic that overweight causes around 300,000 extra deaths in the US every year. As Glenn Gaesser, a professor at the University of Virginia points out, studies have consistently failed to find any correlation between increasing BMI and higher mortality in people 65 and over, and 78% of the approximately 2.3 million annual deaths in the US occur among people who are at least 65. Thus, 78% of all deaths lack even the beginning of a statistical link with BMI. That leaves 500,000 annual deaths in persons under 65 that might be related to BMI. These include deaths from every possible cause: motor vehicle and other accidents, homicides, suicides, cigarettes, alcohol, microbial agents, toxic agents, drug abuse, etc, etc. We are supposed to believe that 60% of these deaths are due to body fat?
Overweight, Obesity And Mortality From Cancer, published in the New England Journal of Medicine in April 2003, was the subject of front-page stories in many of the nation's leading newspapers. For example, a Los Angeles Times article reported that the study provided "the first definitive account of the relationship between obesity and cancer". The article went on to quote the study's authors to the effect that perhaps as many as 90,000 deaths a year from cancer could be avoided if all adults maintained a BMI below 25 throughout their lives. The disjunction between this study's actual data and the alarmist headlines its authors helped generate is especially remarkable.
Among supposedly "ideal weight" individuals (BMI 18.5 to 24.9), the study observed a mortality rate from cancer of 4.5 deaths for every 1,000 subjects. Among "overweight" individuals (BMI 25 to 29.9 - a category that currently includes about twice as many adult Americans as the "ideal weight" cohort), the cancer mortality rate was 4.4 deaths for every 1,000 subjects. In other words, "overweight" people actually had a lower overall cancer mortality rate than "ideal weight" individuals.
It is true that increasing weight is associated with high blood pressure and certain types of heart disease. But even here there is considerable evidence that this correlation is not necessarily a product of being fat, but rather of losing and then regaining weight. Obese patients who have been put on very low-calorie diets subsequently display much higher rates of congestive heart failure than equally fat people who did not attempt to lose weight in the first place. The biggest evidentiary problem for those who insist there is a strong causal link between increasing weight and heart disease is that deaths from heart disease have been plunging at precisely the same time that obesity rates have been skyrocketing.
And, it could be argued that the media is doing the most damage. New diets-particularly the peculiar ones-drive ratings. Sweeps stories aren’t likely to tell you that eating sensibly and working out are the keys to maintaining a healthy weight. But, tell me that I can eat a whole can of Pringles once they zap those pesky trans fats or that meat and eggs are the yellow brick road to bikini season and suddenly we have a STORY – the kind the reaps advertising dollars and inspires those catchy teasers during “must see TV.”
The thing is, we all know better.
This, according to my father is the Mother Diet. We all know from growing up not to smoke, to eat in moderation, to get some exercise. Did anyone’s mother ever tell them that eating a foot-tall stack of Oreos was ok? Common sense and moderation being the best health choices, Americans will be struggling until the pharmaceutical industry reinvents us.
Full disclosure. My BMI is between 18.2 and 18.8 … I’m not sure of my actual weight because I lack the personal restraint required to own an actual scale. But, as of the last time I was at the doctor, 18.2 would be right (and, my pants are a little tighter since then!)
posted by Leigh Householder
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