More Dueling Studies and Contradictory Results

Debra recently wrote a post regarding duelling research. The following post, which I began quite awhile ago, continues on the topic:

In 2006, Dr. Carlos Grilo, a professor of psychiatry and psychology and Director of the Eating Disorders and Obesity Research Program at Yale University published a book entitled "Eating and Weight Disorders".

I found this book through the blog of someone who is passionately concerned with the dangers of obesity. She is interested in scientific texts and puts great weight in what the scientists have to say. So off I went to amazon.com to see what Dr. Grilo had to say.

Here is a quote from the second paragraph from the book's first chapter. The passage reads as follows:

[...] At the other end of the weight continuum is obesity, a common problem that is continuing to increase in prevalence despite pervasive societal pressures and individual desires to achieve thinness. Obesity has one of the highest associated mortality rates of any medical condition. In the United States alone, over 300,000 premature deaths are attributable to obesity annually (Allison, Fontaine, Manson, Stevens and VanItallie, 1999.) Obesity substanstially decreases life expectancy and increases early mortality (Peeters, Bonneux, Barrendregt & Nusselder, 2003). The steady increase in life expectancy observed in the nineteenth century has slowed during the past three decades (Oeppen and Vaugel, 2002) and a recent sophisticated analysis suggests that the United States may face a decline in average life expectancy due to the effects of obesity on longevity (Olshansky et al., 2005).

This is indeed frightening reading and the information, backed up by scholarly studies, is enough to give anyone pause for thought.

The problem is, there is an equally serious (and more recent) study showing that the 300,000 number (some now even say 400,000) is a gross exaggeration. The truth is far more nuanced, as shown in the results of this study from the Journal of the American Medical Association (Cause-Specific Excess Deaths Associated With Underweight, Overweight, and Obesity Katherine M. Flegal, PhD; Barry I. Graubard, PhD; David F. Williamson, PhD; Mitchell H. Gail, MD, PhD):

Results Based on total follow-up, underweight was associated with significantly increased mortality from noncancer, non-CVD causes (23 455 excess deaths; 95% confidence interval [CI], 11 848 to 35 061) but not associated with cancer or CVD mortality. Overweight was associated with significantly decreased mortality from noncancer, non-CVD causes (−69 299 excess deaths; 95% CI, −100 702 to −37 897) but not associated with cancer or CVD mortality. Obesity was associated with significantly increased CVD mortality (112 159 excess deaths; 95% CI, 87 842 to 136 476) but not associated with cancer mortality or with noncancer, non-CVD mortality. In further analyses, overweight and obesity combined were associated with increased mortality from diabetes and kidney disease (61 248 excess deaths; 95% CI, 49 685 to 72 811) and decreased mortality from other noncancer, non-CVD causes (−105 572 excess deaths; 95% CI, −161 816 to −49 328). Obesity was associated with increased mortality from cancers considered obesity-related (13 839 excess deaths; 95% CI, 1920 to 25 758) but not associated with mortality from other cancers. Comparisons across surveys suggested a decrease in the association of obesity with CVD mortality over time.

This quote from the Flegal et al. study is long and complicated. I have seen various interpretations of the results that lead to estimates of from 26,000 to 100,000 additional deaths due to obesity. The study also shows that there are actually fewer premature deaths amongst the overweight (BMI of 30 or less) than amongst underweight or even "normal" weight people (BMI of less than 25). Clearly, there's a big difference between these numbers and 300,000 (or 400,000).

Now, no one is happy about one premature death too many. However, announcing that the sky is falling and well over A QUARTER OF A MILLION people are dying from overweight and obesity, when that is not the case, is very disturbing, especially when one takes into account a) that 95% of people do not succeed in losing and keeping the weight off and b) the level of fat shaming and anti-fat prejudice is growing by leaps and bounds, aided, abetted and inspired by the 300,000 death study.

The Grilo quote makes another sweeping and dangerous generalization: that the increase in life expectancy is endangered by the obesity "epidemic". I am not a scientist, but I can think of other, just as compelling reasons that explain, at least in part, the slowing of the upward longevity curve: the discovery of antibiotics and a growing resistance to antibiotic efficacy. The development of antibiotics created a huge leap forward in life expectancy. However, we are now seeing an increasing number of antibiotic resistant bugs and have yet to find new pharmacological ways to fight them. Medically speaking, such watershed moments are few and far between.

Fat shaming is yet another reason that also accounts for lowered longevity amongst people of higher weight. Overweight--and particularly obese--people tend to shy away from the doctor's office since their concerns and symptoms are often brushed aside by health professionals who attribute all medical problems to overweight. "Just lose some weight and you'll be fine," is the not uncommon message they receive. Dr. Sharma recently wrote an article about fat bias amongst medical students. Attitudes are shocking and completely at odds with the mission of medical professionals: to care and cure. If you want to read actual testimonials of people whose medical problems were ignored due to their weight, take a Valium and then read a blog entitled First Do No Harm, where people tell their own personal stories of fat bias in the medical system.

But let's get back to the statistics--and lack thereof. Here's my question: How much work has been done on understanding why some people are both fat (and yes, even obese) and healthy? What do we know about them? Without having the statistics to back me up, I suspect that there are more people who are both fat AND healthy around than we think. But I don't want to rely on anecdotal evidence, one way or the other. I have read (and received comments) from bloggers who have seen great improvements to their health through massive weight loss. But there are also blogs written by obese and incredibly fit people like Ragen Chastain at Dances With Fat. I dare any one of my readers to keep up with Ragen, who is a professional dancer.

Another study (or in fact, series of studies) that I would like to see would look at the non weight-related effects that improved nutrition and regular physical activity (not of the Biggest Loser variety, just walking, biking or swimming for example) have on people. What would happen to all those "fat, lazy slobs" (not my opinion, I'm just using words that are all too common) the media loves to show us if they didn't, I repeat didn't go on a diet but rather changed their eating habits, started taking a walk every day and got to the roots of their eating disorder (i.e. bingeing), if that were an aspect of their personality. I suspect that some would lose some weight, others would lose a significant amount of weight and yet others would just improve their numbers and their overall health (BP, cholestrol, tra-la, tra-la) without seeing any significant change in weight.

Weight can, but does not necessarily, have an impact on one's health. In the meantime, there are many other factors that are much easier to modify and that can effect significant improvements in health. Why does our society continue to stress weight loss as the only valid marker of good health and the only real action we must take to be healthier? Weight is the most incredibly difficult factor to manipulate--much more difficult than modifying one's diet (as in what we eat, not how much of it) or one's activity level. Why aren't the researchers spending more time looking at these behaviours rather than the elusive holy grail, weight loss?*

*If someone can help me find a study that was done in Quebec about weight maintenance, health status and intuitive eating using a cohort of women, I would be eternally grateful.