Wednesday, December 4, 2013

New Meta-Analysis Adds To Meta-Confusion About Healthy Obesity

sharma-obesity-cardiometabolic-risk1Earlier this week, I posted on a study suggesting that “metabolically healthy” obese individuals are at increased risk for diabetes and heart disease – except that the definition of “metabolically healthy” in this study included people with one metabolic risk factor, i.e. people, who would be considered at least EOSS Stage 1 or 2 – not exactly healthy in my books.

Now, a study, by Caroline Kramer and colleagues from the University of Toronto, published in the Annals of Internal Medicine, unfortunately, adds to the confusion.

The researchers conducted a meta-analysis of data from over 60,000 individuals derived from 12 cross-sectional and prospective studies, varying in duration from 3 to 30 years of follow-up.

Their comparison of metabolically “healthy” and “unhealthy” obese individuals lead the authors to declare that, “there is no healthy pattern of increased weight”.

But of course any meta-analysis can only be as good as the original studies included in it.

And herein lies the problem.

As shown in Table 1 of the study, 9 of the 12 studies defined “healthy” as not having the metabolic syndrome (either based on ATP III or IDF criteria), while the remaining studies defined “healthy” as having less than 2 metabolic risk factors.

As readers will perhaps recall, the ATP III defnition of “metabolic syndrome” actually requires the presence of at least 3 of 5 of the components of the metabolic syndrome, while the IDF definition actually requires abdominal obesity AND at least two other risk factors.

Thus, someone with just hypertension or just elevated triglycerides or even just elevated fasting glucose would be considered to be “healthy” in these studies.

This of course is nonsense. The term “healthy” should mean just that – “healthy”.

In the Edmonton Obesity Staging System healthy is defined as the absence of medical, mental or functional risk factors or limitations related to excess weight. According to this rather “stringent” definition, our analysis of NHANES and other data sets, showed virtually no increased risk associated with increased BMI or waist circumference over as long as 200 months.

In contrast, in our analyses, obese individuals with even just one metabolic (or other risk factor) were considered to have EOSS Stage 1 or 2 had clearly elevated risk.

Thus, this meta-analysis simply adds to the confusion on this topic by defining “healthy obesity” that we would consider anything but “healthy”.

Nevertheless, the paper does make two interesting points – neither of which are novel or unexpected:

1) There is considerable metabolic heterogeneity amongst people with elevated BMI.

2) People with elevated BMI (including those at lower risk) are at a higher risk of eventually developing metabolic problems (with increasing age and BMI).

Thus, for clinicians, the message really remains the same:

1) BMI is a lousy measure of metabolic risk in individuals.

2) Even those with elevated BMI who appear at lower risk, should work on maintaining that lower risk (as should everybody else).

Unfortunately, studies such as this, by mislabelling unhealthy obese individuals as supposedly “healthy”, do little than further confuse the literature and promote weight bias while reinforcing the widespread misconception that you can measure health by simply stepping on a scale.

If you are an obese person with Stage 0 obesity and have maintained that “healthy obese” status for years, I’d like to hear about it (yes, these people do exist).

@DrSharma
New Delhi, India

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21 Responses to “New Meta-Analysis Adds To Meta-Confusion About Healthy Obesity”

  1. Melinda Munro says:

    I’m one of those EOSS 0 people who has been healthy my whole life. I was an obese infant who had a short period of a BMI of 25 in my mid 20′s and never has again. Current BMI is 32. Despite that, I run and go to the gym regularly and have no metabolic risk factors or other co-morbidities, with the exception of worry about the nagging pressure of studies like the one you cite, suggesting that I am unhealthy. In response, I wear an UP band to prove I am active and I journal my food every day and have for about 10 years. That constant background noise of wishing I “looked normal” might be considered one of your co-morbities. I fantasize about a miracle cure like a way to create BAT out of all my flab.

    I also come from a long line of women who have struggled with their weight. Photos from the early 20th century (1920′s) are replete with women (grandmother and aunts) who all look just like me and if they didn’t die of infections (TB or appendicitis) lived well into their 90′s and older.

  2. Doug Armstrong says:

    Absolutely correct. What is in the thinking process of those who deem the presence of 1 comorbidity as being healthy? WDA

  3. Michelle Archer says:

    Greetings Dr. Sharma

    I also fall into the EOSS Stage 0 and have for as long as I can remember. I am a 40 something registered dietitian who also felt the pressure of studies that said I was overweight-obese when I have always been active and had great health. Dieting to lose weight was always total failure for me. My health has always been a success though. My blood pressure is usually 90/60, cholesterol and fasting sugars are normal, I eat well (sometimes too well!) and am active, usually running or walking and occasionally a weights class at my local Y. My WC is 36 which is high for a woman but I am 6 feet tall and over 200 pounds. Physically I am larger than most other woman. I sleep well, laugh lots and surround myself with positive, caring people.

    I too wonder if the stress of not fitting into the “normal’ BMI range should be considered a risk factor for decline in health. I know that negative thoughts about oneself does lead to negative behaviors and feelings. Once I accepted that I am not ‘normal’ by the BMI standard but healthy by all other accounts, I began to be happier and embrace my differences!

    Thank you for keeping me informed on the obesity research! I really appreciate all that you do for all of us out here in the trenches.

  4. Christina RD says:

    Fortunately there was a dietitian on CBC this morning who pointed out the authors didn’t look at exercise!

  5. Bobbini says:

    I am EOSS stage 0 with a BMI over 30 and have been all my adult life. At 45, I’m within 10% of the weight I was at 22, and can still wear clothes from college. I recently had lab work for health insurance purposes and my cholesterol, fasting glucose, etc. were all within the normal range. My blood pressure is fine as well–as good as my husband’s, and he’s maintaining a 90 lb. weight loss and spends 10 hours a week at the gym.

    I’ve had two full-term pregnancies without major swings in my weight, both times with healthy babies and straightforward deliveries. The first pregnancy came with gestational diabetes (easily controlled), the second one did not.

    I am not very fit right now–not very active in everyday life, though I wouldn’t describe myself as completely sedentary. My diet is varied–some weeks much “better” than others.

  6. CE says:

    I’m not sure if I’d be considered EOSS 1 or not, as I have mild pre-hypertension (typically 122/82 or slightly higher, well below hypertensive.) Current BMI just over 27, so overweight, not obese. I’ve been this weight for a long time now. I exercise more, eat better and would consider myself in better cardiovascular shape than I was 25 years and 25 pounds ago.

    To add insult to injury, many of the news headlines proclaimed “Fit and fat a myth” even though the study looked at metabolic measures, NOT fitness level. In fact, the authors stated that cardiorespiratory health was a strong indicator of mortality independent of BMI.

  7. Katharine de Baun says:

    Dr. Sharma, I have recently discovered your blog and was hoping you would blog about this latest meta-study so I could show my co-workers here at Life180 Inc. Thank you! (We provide online coaching services to teen girls who want to live healthy and manage their weight — we also have a program for parents). One of our values as a company is to help teen girls feel better about themselves and feel empowered to take charge of their health — regardless of their size.

    When you think about weight in historical terms, the fact that ~15% of overweight/obese people remain metabolically healthy makes sense. There have always been weight extremes in human bodies over the ages. What has changed is that the bulk of us in the bell curve (the belt curve) are getting fatter.

  8. Leoluca Criscione says:

    …in our book: “Eating healthy and dying obese, elucidation of an apparent paradox”, we have a chapter with the title” Science feeds confusion”… And the chapter is becoming longer… up to the “zero credibility” time…. (non that far!!!

  9. Jennifer D. says:

    I too am healthy, even though my BMI is 38. I have been a patient of Yoni Freedhoff, who can vouch for my good health! I am in my forties and practice Karate 3-4x per week, and I can perform exercises that many people 20 years younger than me would find impossible. These studies are tiresome. Even if the results were 100% true, how would it help? It’s not as if fat people don’t already know the potential risks of being fat. Most people hate being fat, so there is no need to tell us it’s a bad thing. It’s time to focus on people’s abilities and encourage their passions – never mind what size they are.

  10. Dee M. says:

    I’ve been “obese” since childhood. I wore a size 18 at 11 years old. After noticing the yo-yo diet followed by weight gain pattern in several family members, I made a decision early on to stay active and eat a healthy diet, but not to go on any restrictive weight loss diets. My BMI has always been between 32 and 37 or so. I’m 44 now and I’m still metabolically healthy, with no risk factors. The amount of exercise I get and my eating habits have varied a little over the years, but I’ve always been at minimum a regular walker, and I’ve always eaten a balanced (as opposed to low fat or low carb) diet with lots of fresh produce.

    Like the poster above, I have 1920s pictures of family members who were built just like me, most of whom lived well into their 80s despite having had tough lives. I look a lot like my dad’s mom. My dad’s generation – the generation who dieted – are a lot heavier. My mom has always been thin, but there are a few people in her immediate family who have gotten pretty heavy (bigger than I am) over the years. All of them started dieting when they were fairly thin and gained back extra weight after each period of weight loss. So, growing up, I saw weight loss dieting very obviously resulting in long-term weight gain in my dad and in four or five aunts and uncles on both sides of the family. It might not be a big enough sample size for a study, but it was enough to convince me not to go the same route. So far, things have been working out pretty well.

  11. Anonymous says:

    “In the Edmonton Obesity Staging System healthy is defined as the absence of medical, mental or functional risk factors or limitations related to excess weight. ”

    I assume a “medical” risk factor is something a doctor measures. (like blood labs work.)

    How does EOSS determine ‘Mental” risks or limitations?
    If a person says they find their obesity embarassing so they don’t go out much, is that counted as a “mental risk or limitation due to obesity”, or is that dismissed because the embarassement is really only a reaction to a fat-biased society? (ie the problem is society , not obesity, so it doesn’t count as a “limitation due to obesity”.)

    How does EOSS determine functional limitations?
    Does a doctor have a person undertake physical exercises which would be easy for a healthy person and see how the patient performs?
    Or does a doctor just ask a patient if they are limited by their weight?
    The problem with “just asking” is that many obese people have over the years adapted to their condition, like the proverbial frog in the slowly heating pot of water. They don’t realize how much slower and less agile and less endurance they have compared to a healthy weight person.
    If a doctor asked an obese patient if they had functional limitations and they said “No, I can do everything I want to do, which is read, knit, and watch TV”, would the doctor check off “no limitations due to obesity”?
    Or would the doctor also have the patient actually do exercises. The person might not be able to do what a healthy person can do. Would the doctor then note – “physical activity limited by obesity, patient is EOSS 1 ? ” If the patient has severe limitations on physical activity but it doesn’t affect him because he’s sedentary anyway, is that irrelevant in evaluating health?

    I believe, Dr Sharma, that you have cautioned people not to set their goals by those well publicized individuals who lose massive amounts of weight relatively quickly and keep it off. As you point out, those dieters are rare outliers and not everyone can expect the same results.

    EOSS stage 0 people certainly exist (like Melinda above), but they also are comparatively rare. (Though I’m sure you’ll hear from many with their personal stories). The danger is that everybody will assume that they themselves are EOSS 0 (like everybody who buys a lottery ticket expects to win, odds be damned). As you have pointed out, even one problem kicks you out of EOSS 0. That one problem can be all too easy to miss or ignore.

    Another danger is that if obesity is perceived as healthy in itself though other accompanying diseases are a problem, the public health system won’t have much motivation to combat obesity. It doesn’t make sense to base public health policy on the rarest category of obese people, instead of the many more people in EOSS 1 and higher, but it can be used as an excuse to do nothing.

  12. Melinda Munro says:

    Anonymous,

    Why do you assume that obese people lie? If a doctor who understands the EOSS system asks you if you have any functional limitations why would they accept a mediocre answer without probing.

    I wonder if you think I am lying about being EOSS 0. What would it take to prove it to you? I have had the full battery of blood tests, stress tests, fitness tests, I hold the record at my gym in various categories of strength, cardio and general fitness. Does that mean my gym must be full of other limited people? I was amused to hear a couple of “normal weight” women talking about how they don’t have to take showers after a workout because they don’t sweat much. Hmmm. What kind of a workout leaves you without sweating, especially if you tax your heart rate? Are they healthier than me?

    According to Sharma’s research EOSS 0 and 1 are not “comparatively rare” but as many as 20% of the population.

    How many “healthy weight” people have metabolic syndrome or other issues? If asked if they were limited would they say yes?

  13. ksol says:

    Anonymous — isn’t the point to combat the actual diseases rather than to combat body size? What if it was found — and it has been — that obese people who maintain healthy habits are not at greater risk for mortality? Even the editorial that accompanied the study said that cardiorespiratory fitness was a strong indicator of mortality independent of BMI.

    And just because some people will use this to be in denial is no excuse for treating people with inappropriate medical interventions. Plenty of people are in denial right now thinking they are healthy because they’re in the accepted BMI range, even though they may have risk factors. Wouldn’t assessment of actual risk factors across all weight ranges make the most sense? Wouldn’t all people benefit from the recommendation of exercise and a healthy diet without having to tie it to intentional weight loss? Isn’t this where public health could focus its efforts more effectively?

    Even people who aren’t in EOSS 0 might make a rational decision not to engage in weight loss based on the cost and benefits, particularly since risks of intentional weight loss include additional weight gain and eating disorders.

    This idea that it is “dangerous” to speak the truth does not fly with me.

  14. Karen P says:

    I was obese on and off from age 6 to age 45. My BMI was 35 and my bio-markers, Hemoglobin A1C was trending toward pre-diabetes and my CRP was 6.8 (normal is <3).

    My doctor rightfully so warned me that I would soon have multiple chronic health problems and I put top priority on losing weight. So, so glad to have the annual blood work (required for a $30 a month discount) by my employer so I could take my health into my own hands.

    Glad that the use of blood work markers are being mentioned. It gives a bigger picture and can help individuals work as a team with their doctors to make the right decisions for themselves. No one single answer. Customizing is key- IMO.

    My blood work returned to normal when I ate low inflammatory and now maintained my weight loss (BMI now 22 or so).

  15. CarolynS says:

    The Kramer meta-analysis is very problematic. You have to read it carefully to see this, but the relative risks they have in their article are not the relative risks from the studies that they cite. They only took the sample sizes and numbers of events from the studies, then they calculated their own relative risks. As a result their relative risks are completely unadjusted. They are not even adjusted for obvious confounding factors like age and sex! And the relative risks in their plots are often quite different from the actual relative risks published in the articles that they review. For example, the Kuk and Ardern paper in the Kramer analysis has a relative risk of 0.96 (0.52–1.39) for (metab normal overweight) vs. (metab normal normal weight), but if you look at the Kuk and Ardern paper, they actuall showed a relative risk of 0.45 because they adjusted for age, sex, smoking, income, alcohol consumption and ethnicity. It’s quite questionable as to whether the unadjusted estimates in the Kramer article are really meaningful.

  16. Mike Marini says:

    I agree that it is possible to be healthy and still be heavier than the accepted “standard” based on BMI

    That being said, it behooves EVERYBODY, not just people who are heavier, to periodically review their inventory of risk factors and limitations

    That means getting a REAL physical exam, not just the 5min “How are you today?” jokes that are often the norm…

    -targeted lab work for metabolic and inflammatory indices
    (there are still GP’s who insist that CV disease has nothing to do with systemic inflammation BTW)

    -some kind of exertion-based activity test (treadmill stress test, , stair step test, obstacle course, flexibility measurements

    -and, from a psychological POV, the “naked in the mirror test” metaphorically speaking, where you have an honest conversation with yourself about how you see yourself and how that impacts your self esteem and relationships.
    (for me, I picture myself wheeled into the ER or an operating theatre, in a gown, and how my current level of fitness would be assessed by my colleagues)

    If you are passing all these tests, your weight probably doesn’t currently impact your health, it might in the future, but not now.

    If you AREN’T passing these tests, or have strong family history for metabolic disease,
    then you owe it to yourself to change what you can and get as close as possible to the ideal state of “you”

  17. Anonymous above says:

    To Melinda:
    No, I don’t think you’re lying. I referred to you as one of those who are EOSS 0 because I believe you.

    As for my questions about what EOSS considers “limitations” – I’m just wondering what the system is …
    if an obese person honestly feels she has “no limitations” because she can do what she wants, which is knit and read, is there any point in considering her “limited” because she can’t do gym workouts which she has absolutely no interest in doing anyway?

    Is being able to do gym workouts necessary for health or are they just something some people enjoy? Many people are healthy without ever going to a gym.
    (Though if I owned a gym I would be claiming everybody should be there for the “health benefits”.)

  18. Anonymous above, again says:

    To Melinda, again,

    I said that healthy obese people are “comparatively rare”.

    From your post:
    “According to Sharma’s research EOSS 0 and 1 are not “comparatively rare” but as many as 20% of the population.”

    From Dr Sharma’s post of today, Dec 9, 2013
    …..
    “As stated, the paper does not actually study healthy obesity, as many of the participants had more than 1 comorbid illness or had preclinical metabolic conditions.

    In this paper, 24% of participants were defined as having healthy obesity (taken from the raw numbers).

    In contrast, in a previous article that we published (in OBESITY), we found only 3.6% of obese individuals presenting in our clinic to truly have “healthy obesity”, i.e. no preclinical markers.”
    …..

    Considering EOSS 0 as healthy and EOSS 1 as unhealthy, it seems like there are many fewer healthy obese people than the 24% claimed by the big study.
    On the other hand, there are probably more “healthy obese” than the 3.6% found in the clinic, simply because the people going to the clinic are the people having problems. Clinic patients aren’t a random sample.

    So, definitely less than 24%, maybe above 3.6% – I’ll stick with my contention that healthy obese people are “comparatively rare” among obese people. Even if that works out close to your 20%, they are far in the minority – 80% of the obese are unhealthy.

    Which doesn’t mean a doctor treats an individual patient like a statistic and assumes an obese patient has whatever is statistically likely – no more than a doctor would assume a patient with stomach upset has intestinal flu just because the last 8 patients he saw had intestinal flu causing stomach upset – maybe this patient has appendicitis.

  19. Linda says:

    My weight has yo-yo-ed for decades, and at age 58, I am now at my highest weight. My BMI is currently 42.5 (63 inches tall; 240 pounds). Despite that, my cholesterol is 139; HDL 73 (ratio 1.9): triglycerides 104; Liver enzymes WNL; fasting glucose is 81. My BP varies, but is always within the normal range. It typically runs 90/60. I had some joint and muscle aches last year, but was also vitamin D deficient. The aches went away once I started correcting the problem. I had roux-en-Y gastric bypass surgery in 1981. I lost nearly 100 pounds (232 – 138) within the first two years post-operatively, which slowly creeped back after I had children beginning in 1992. Some say that my metabolic profile is due to gastric bypass surgery, but these numbers pre-date my surgery. I credit my 40 year adherence to a vegetarian diet, which is mostly plant-based.

  20. Linda says:

    Correction: Those blood work numbers do not literally pre-date my surgery. They are from 2013. I meant to say that my blood work was ideal even before my gastric bypass surgery, and continues to be good. I have the records to prove it!

  21. LH says:

    I’m one of those people. I’ve been fat all my life, and lab work has always come back in normal ranges. I’m 47 years old now — middle-aged — and I have yet to suffer physically from being “obese”. I am mildly active: yoga, yard work, walking, biking. I enjoy strenuous activity occasionally, such as when stacking wood. For years I’ve eaten whole foods and as I’ve become aware of allergies I’ve cut way back on grains and dairy. I am conscientious in my self-care. I don’t know why my body wishes to hang on to more adipose tissue than average, but it doesn’t bother me and I’m certainly not going to subject it to hunger and painful exercise in the name of “health”.

    I have no doubt that fatness in the general population has myriad causes that our cultural emotional bias is keeping us from seeing clearly, and that these include disordered eating caused by shame and social expectations, chemicals that our bodies shouldn’t be exposed to and that affect certain genotypes more than others, attempts at weight loss that cause the body to become more efficient at conserving fat stores, and (possibly) just normal variation in a population that has an adequate food supply.

    We may be able to say that statistically fatness is correlated with higher risk, but we absolutely cannot say that fatness is a guarantee of ill health anymore than we can say that thinness is a guarantee of good health, and it seems to me dangerous to imply that it is so; we end up with a situation where thin people think they can do whatever they want and not suffer the consequences because they equate thinness with health, where otherwise healthy “overweight” people cause trauma to their bodies in an attempt to be thin, and where the health of fat people is adversely affected by stigma and discrimination.

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