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Class 1 Obesity: Don’t Worry, Be Happy?

According to a landmark paper in this week’s issue of JAMA, I now realize that I need to gain about 75 lbs to get the most out of my pension plan.

Indeed, that is just about how many extra pounds I would need to pack on to achieve a BMI of 33, which would finally put me squarely in the Class 1 obesity range. That, according to this extensive review of the literature, would bestow me with the longest life expectancy.

Unfortunately, this will not be easy – If I recall correctly, Morgan Spurlock (the fellow in Super Size Me) only managed to gain a measly 25 lbs – and I recall how hard he had to work at this.

Or, could it perhaps be that the results of this paper are so obviously nonsensical, because the researchers asked the wrong question?

After all, who still cares about BMI?

I can only assume that my US colleagues were far too busy running their analyses to have time to read the Canadian Medical Association Journal (CMAJ or Canada’s version of JAMA), which happened to publish our analysis of data from the US(!) National Health and Nutritional Education Survey (NHANES) on this issue.

As readers of these pages may recall, our analysis of applying the Edmonton Obesity Staging System (EOSS) to two independent NHANES datasets, essentially showed that when it comes to mortality, what matters is how “sick” your are and not how “big” you are.

If you have a weight-related health problem (i.e. EOSS 1+), you die, if not, you don’t – end of story!

Neither BMI nor waist circumference were much use in predicting mortality – but whether or not you had hypertension, diabetes, or sleep apnea was.

As we outline in our paper, not only would BMI overestimate health problems in millions of US citizens, it would also completely miss about 25 million Americans, who do have weight-related health issues, despite falling well below the BMI 30 obesity range.

Perhaps, after this paper, we can finally lay BMI to rest and stop trying to predict people’s health with just scales and measuring tapes.

Hopefully, the only landmark that this paper leaves behind is a tombstone – BMI – RIP!

Let us now get back to actually taking a good medical history, doing a thorough physical exam, and running some tests before declaring someone too light or too heavy for their health.

And in the meantime, let’s not forget that prevention best starts by not losing sleep over your weight unless you have to.

Edmonton, Alberta


  1. I did read your study, and I agree with everything written here regarding BMI and weight. Sadly, within both the scientific and medical community, the general response is usually along the lines of well, we know BMI is problematic, unless you’re fat, and then you’re going to die. Soon.

    Studies such as the Flegal one – although not telling us anything new at all (not that you’d know it to believe the press) – do at least draw attention to the fact that obesity need not be a death sentence or a walking morality judgment.

    Pretty much everyone can grasp the concept that not all thin people are healthy, but after decades of the contrary view being shoved down our throats, most people really struggle with the idea that not all fat people are unhealthy. This is also not news. But today it is. And I think that is a good thing.

    Now can we all get back to looking at HEALTH rather than weight.

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  2. I wish someone would tell family doctors that the BMI is dead. The BMI chart was still tacked up on the walls of clinic offices at the Bruyere Family Medicine Centre the last time I was there, and doctors still refer to it. If it’s not useful, there needs to be a policy change that gets doctors to stop using it as a way to predict health outcomes.

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  3. I have not read the paper yet, though I intend to. But I seriously doubt that Dr. Flegal is saying that people need to achieve a BMI of 33 to be at their ideal weight. My understanding is that the paper is merely saying that our current assumptions about the risks of being overweight or being mildly obese is not nearly a threat as society makes it out to be. It makes no more sense to assume that the study is advocating obesity as an ideal weight for everyone than the current assumption that a “normal” weight is the ideal for everyone. What matters is behavior and, as you state, the metabolic indicators of health. Perhaps if contemporary obesity research would routinely control for physical fitness (as Dr. Steven Blair advocates), rather than simply publishing headline-grabbing papers using BMI only, then we would have a more realistic expectation of what effect excess weight has on our health. Instead, the current research focuses solely on weight and assigns blame for the correlated morbidities to our size, rather than the missing variables of lifestyle.

    I’ll have to read Dr. Flegal’s paper before I can respond conclusively, but this exaggerated reaction to a meta-analysis of mortality statistics is getting kind of absurd. NHANES has previously shown that the overweight category has the best mortality statistics, so this isn’t exactly a shocking report, IMHO.


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  4. Dr. S: Would it be too much to fantacize that someday your Edmonton Staging System might become the EWSS, as in Edomonton Wellness Staging System? In this fantasy, obesity, as we now think about it, in terms of BMI (which is worthless), would not be the presenting factor that compelled patients to see their doctors, but rather, perhaps, a symptom among many (especially if it’s severe and/or visceral). Hmmmm.

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  5. Hello Dr.Sharma ! you are right life is too short and we don’t have to be depress if something will happens bad with us because there are many other peoples who Loved Us and they want us to be Happy and enjoy the Life !

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  6. As a reviewer for a mainstream obesity journal, I am well aware of how one legitimizes publications based on accurate simple parameters, like BMI. Dr Sharma, thank goodness, keeps us honest. Think before we publish stupid conclusions based on simple and imperfect measurement parameters. I sure am not going to gain weight to make it into the safety net of the mildly obese. JAMA use some common sense.

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  7. If BMI is irrelevant, then maybe we could stop automatically referring to the indicators of metabolic syndrome as “weight related?” I’m not suggesting that there aren’t correlations, but people of all sizes have these health problems, and they may not be *caused* by fat tissue or by weight.

    We could just as accurately refer to them as “SES related,” “hereditary,” “ethnically influenced,” “lifestyle related” or in terms of any other correlating factor. Why is it always “weight related?”

    Just a thought.

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  8. The indicators/symptoms of metabolic syndrome are highly correlated with obesity and, if untreated, will likely cause sickness. This is not to say that all obese individuals do have these components of metabolic syndrome, but they are at much greater risk statistically of developing the symptoms. The point of this article is to say that if someone is obese and has been lucky enough to beat the odds statistically of developing these symptoms, then they are likely to live longer and more healthy.

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  9. Hi All,I’m 25 years old and I weigh around 252lbs. I have a child with sacepil needs so it seems a little harder to make time for work-outs and diet planning. He fights me on eating but will eat whatever I eat.. as long as I’m eating it too. HOWEVER, I know some of you will say eat healthy foods , well, my son’s doctor put him on a sacepil fatty’ diet because he’s 6 and weighs 23lbs. My hubby and I want to have another child soon, but I can’t possibly imagine having another child let alone actually have another child and getting BIGGER. Before I had my son I weighed around 180 and I was happy with that, now it seems like I can’t lose any weight. I was told I gained alot of weight due to preeclampsia. It causes fluid build-up. Any suggestions will be great. I look at this page almost daily.Thanks in advance.

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    • Thanks Nabeh for your comment – unfortunately, I cannot give any personal medical advice on this site – you will have to discuss this with your family doctor.

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