Is it irresponsible to call obesity an "epidemic"?

[handsomeharry]

@Foldup Rabbit

No, I absolutely agree that people should be getting excited about obesity. Er… I mean, getting excited about fighting obesity. I just don’t really like the way the word “epidemic” is tossed around. It seems that after a word or phrase reaches the status of buzzword, it rides the peak for a while and then starts to lose all appreciable meaning.

Ha! Evidently, you haven’t heard of the word 'abuse!"

hh

[Loopydude]

There was a rapid increase per capita in BMI over the latter half of the 20th century into the 21st, and a concomitant increase in the percentage of the population fitting the medical definition of obese. Obesity as defined is a pathological state, with a reasonably well-characterized syndrome and significant comorbidity. So, you’ve got a rapid and unexpected increase in the incidence of a particular pathology affecting a particular population (primarily those living in the USA, especially sub-populations thereof). All the basic criteria of an epidemic have been met. There’s nothing remotely irresponsible about the use of the label in this case. What the media does with this information, or their misapplication of the terminology, is not the fault of epidemiologists.

[Waenara]

@Waenara

Regarding the bolded claim, I have a few cites that I’ll be able to dig up later today.

IIRC, some very large studies showed that the BMI that was best for longevity was 25 to 27. (Of course, healthy BMI is defined as 20 to 25 and “overweight” starts above 25). It was very interesting.

I’m on my lunch break now, and wrote up a summary of information from a book I read recently:

The following information comes from the book The Diet Myth by Paul Campos (previously published until the title The Obesity Myth. I’ll quote some excerpts here, which I think aren’t too big and fall under “fair use.”

However, let me just say right away that this book does not try to claim that being overweight is great and that morbid obesity is just dandy. Rather, he’s saying that the medical risks associated with being somewhat overweight are exaggerated, and that you need to get into very high levels of obesity (100 to 150 pounds overweight) before the medical risks are significant. At that point, there’s no kidding yourself that your weight isn’t harming your health at all. However, relatively few people are at this extreme. The vast majority people who qualify as overweight are not that overweight. Also, weight loss is difficult to maintain, and the majority of dieters regain all they lost, or even more. “Yo Yo” dieting is much more dangerous to your health than just being overweight in the first place.

Some main points that he makes are:

[quote]
[ul][li]The health risks associated with increasing weight are generally small, in comparison to those associate with, for example, being a man, or poor, or African American.[/li][li]These risks tend to disappear altogether when factors other than weight are taken into account. For instance, fat active people have half the mortality rate of thin sedentary people, and the same mortality rate as thin active people.[/li][li]There is no good evidence that significant long-term weight loss is beneficial to health, and a great deal of evidence the short-term weight loss followed by weight regain (the pattern followed by almost all dieters) is medically harmful. Indeed, frequent dieting is perhaps the single best predictor of future weight gain.[/ul][/li][/quote]

At bottom, the diet myth is both a cause and a consequence of what sociologists call a “moral panic.” It is a particularly tenacious example of the same sort of impulse that fueled hysteria about demon rum, reefer madness, communists in the State Department, witches in Salem, and many other instances of our eternally recurring search for scapegoats, who can be blamed for the decadent state of American culture in general, and of the younger generation in particular.

This book does not argue that there is no relationship between weight and health. It argues, rather, that the health risks associated with higher-than-average weight have been greatly exaggerated, while all sorts of related but far graver risks have been ignored. In particular, this book emphasizes that poverty, poor nutrition, and a culture that makes it easy for Americans to be sedentary are important public health issues in America today. We should be encouraging Americans to be physically active, to eat well, and to provide reasonable access to medical care for those among us who lack it. What we should not be doing is telling Americans that they will improve their health by trying to lose weight. As we shall see, there is very little evidence that attempts to achieve weight loss will improve the health of most people who undertake them, and a great deal of evidence that such attempts do more harm than good.

Some quotes and research from the book, italics are in the original and bolding was added by me:

Time after time… studies failed to find the “right” correlations between increasing weight and increasing mortality. For example, here are some figures from what – at the time it was compiled – was the world’s largest epidemiological study to date. This study, conducted in Norway in the mid-1980s, followed 1.8 million people for ten years. Consider the following data in light of the government’s and the medical establishment’s claims that a BMI of 18.5 to 24.9 is optimal, and that people with BMI figures of 25 and above are running major health risks. The highest life expectancy (79.7 years) was found among people with BMI figures between 26 and 28, all of whom were overweight according to current U.S. government guidelines. The lowest life expectancy (74.2 years) was found among those with BMI figures below 18 (a woman of average height who is 5 pounds below what the government claims is her “optimal” BMI will fall into this highest risk category). Those with BMI figures between 18 and 20 – most of whom were at what our public health authorities claim is an optimal weight – had a lower life expectancy than those with BMI figures between 34 and 36: people who according to these same authorities were roughly 60 to 75 pounds “overweight” and therefore seriously “obese.”

This Norwegian study is: Waaler et al., “Height, Weight and Mortality: The Norwegian Experience, Acta Med Scanda Suppl 679, 1-5 (1984).

From: Troiano et al., “The Relationship Between Body Weight and Mortality: A Quantitative analysis of Combined Information from Existing Studies.” Int J Obesity 20, 63-75 (1996).

A 1996 study 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 six hundred thousand subjects with up to a thirty-year follow-up, making it, in the words of one prominent obesity researcher, “one of the most comprehensive analyses of the relationship between mortality and body weight published to date.” The results of this analysis should startle anyone who has assumed the government’s BMI recommendations are actually justified by the available evidence. 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”… The mortality range 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 currently as “obese”)… In regard to non-smoking white women… 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.”

From: Menotti et al., “Underweight and Overweight in Relation to Mortality Among Men Aged 40-49 and 50-59 Years: The Seven Countries Study”, am J Epidemiol 151, 660-66 (2000).

Yet another recent example comes from the famous Seven Countries Study, which has tracked thousands of men from seven different nations (the United States, Japan, Finland, Italy, Greece, the Netherlands and the former Yugloslavia) for more than forty years. None of the many medical articles published on the basis of the data from this study have indicated that, in terms of life expectancy, it is better to be thinner than average. Indeed, a recent report on nearly eight thousand Europeans from the study found that thin men (those with a BMI less than 18.5) had roughly twice the mortality rate of either normal weight or “overweight” men. And this remained trued without regard to smoking status. Although being “obese” (BMI 30+) did increase mortality, the death rate of men in this category was still lower than that among thin men.

Basically:

While very fat and very thin people tend to die sooner than average, there appears to be a very broad range of weight – running roughly from a BMI in the high teens to one somewhere well into the thirties – at which little or not correlation between weight and mortality can be found… Indeed many such studies find the lowest mortality levels at BMI figures that are currently classified as “overweight.” Furthermore, given current government guidelines, it appears that the average person is better off being 50 or even 75 pounds “overweight” than 5 pounds “underweight.”

Anecdotally, I also remember that in my first year of university I took a course on heath and wellness (a requirement for my Physical Education degree program). At that time, in 1997, a normal BMI was defined at 20 to 25, “caution” was 25 to 27, overweight was 27 to 30 and obese was 30+.

Several years later, they eliminated the “25-27” category, and now just call those people overweight. So people who previously had been simply “high normal, watch out in case you gain weight and become overweight” were now simply “overweight.”
Full disclosure – I have been extremely overweight (5’5” and 275lbs). I have been tracking calories and eating healthy for about a year and a half and have now lost over 55lbs (currently 218) and I plan to continue losing more weight. My eventual goal is about 150 to 160lbs (which would be a BMI of 25.0 or 26.6 – considered the absolute upper limit on “normal”, verging into “overweight”).

I lost the initial weight for health reasons, but I’d be kidding myself if I didn’t admit that my goal of 160 is mostly out of vanity – I was extremely fit at that 170lbs when I was eighteen, and if I only get down to about 180 and maintain the weight loss without regaining that I’ll have done as much as is needed, statistically speaking, to be more healthy. The extra 10 to 20 lb loss would just be to look better in a bathing suit. Which is a good goal – but it’s not for medical reasons.

[Malthus]

I think that these three statements are true, just based on what I see around me and read:

1. Being a trifle overweight is not a big deal, healthwise. Good nutrition and healthy activity are more important than a simple measurement of weight to height like the BMI. In short, I find Waenara’s quotes persuasive.

2. There is a bit of a “moral panic” atmosphere about the weight issue.

3. People are on average getting fatter every year, and this is a genuine public health problem.

Disclosure: I have myself recently lost 40 pounds, and I’m now 6’ and weigh 195 pounds. I’m starting my exercise regime in a gym that is in the same building where I work on Monday.

[Lissa]

@Malthus

2. There is a bit of a “moral panic” atmosphere about the weight issue.

A bit, maybe, but I don’t think I would qualify it as a real “moral panic”. It doesn’t have the elements usually associated with it:

1. A public outcry for someone to do something to protect them

2. A vague but intensely-felt sense of having “our way of life” attacked

3. The dehumanization of the culprits.

Fat people are not seen as “the enemy”, but rather people who need help. Obesity is thought more along the lines of an illness, not as an overtly anti-social act.