The Edmonton Obesity Staging System Is Not A License To Do Nothing!

Amongst all the enthusiastic accolades that welcomed the publication of the two recent papers showing that the Edmonton Obesity Staging System (EOSS) is superior to BMI in predicting mortality risk, there were some commentators (including readers of these pages), who apparently misinterpreted these findings as ‘a license to be fat’ or even ‘as sending a devastating public health message that fat can be healthy’.

While the lay media and lay readers may be forgiven for this simplistic and cursory interpretation of our findings, more sophisticated readers should actually have noted that nowhere in these papers (or in the original proposal for EOSS) do we ever equate EOSS 0/1 (low risk) with doing nothing.

In fact, we were very careful in pointing out that even patients presenting with EOSS 0/1 should be investigated for underlying drivers of weight gain and should be counselled on prevention of further weight gain (weight maintenance) and, insofar there is indeed any additional room for improvement, to eat healthily and get as much activity as they can enjoy.

The caveat regarding ‘additional room’ was put in to imply that, yes, people in lower EOSS categories already appear to be eating quite healthy and certainly are more physically fit than their higher-risk EOSS counterparts (meaning – they may already be doing the best they can).

To me, investigating someone for the causes of excess weight, counselling on weight maintenance, and scheduling repeat consults (say at 12-18 months) is not ‘doing nothing’. It is also by no means ‘a license to be fat’ (as if being fat – per se is a bad thing).

In fact, the whole point of EOSS is to better identify and focus treatment on high-risk individuals while pretty much leaving lower-risk EOSS folks alone (albeit with minimal investigation and intervention).

But of course, this notion is unlikely to appease the ‘weight-loss-at-all-cost’ enthusiasts, who firmly believe that there is something inherently ‘unhealthy’ about extra fat (when clearly our studies show that there isn’t).

These ‘weight-loss-enthusiasts’ will also make the ‘prevention’ argument, which of course is based on nothing, given that there are indeed no studies showing that obese people who are currently healthy (or which subset of these) will actually progress to developing relevant morbidity, IF THEY CONTINUE TO MAINTAIN THEIR CURRENT WEIGHT AND HEALTHY LIFESTYLES!

As it takes months if not years or even decades to progress from one EOSS stage to the next, and as most health problems in EOSS 1 and 2 (by definition) are reversible, there is really no argument to pre-empt these problems by recommending weight loss to people, who really have no weight problem.

Indeed, if the first rule of medical practice is ‘do no harm’, I would be the first to point out that recommending weight loss to someone, who is essentially healthy, actually does have the potential to do harm.

Firstly, this person could go out and begin engaging in unhealthy weight loss practices just to get those supposedly ‘extra’ pounds off – this practice alone could pose a health risk.

Secondly, losing some weight only to put it right back on (as do 95% of people who try to lose weight) may well have negative physical and emotional consequences (not to mention the negative impact on their wallets).

Thirdly, having engaged in ‘unsuccessful’ weight loss may make this person less motivated and perhaps even less likely to succeed in losing weight, when, at a later time, this may indeed be indicated – crying ‘wolf’ now may simply lead to the real wolf being ignored later.

But here is a final argument that could perhaps appease the ‘weight-loss-at-any-cost’ enthusiasts – we are (sadly perhaps) only talking about a minority of overweight and obese people, to whom this ‘low-risk’ status actually applies.

Thus, in the overweight category, only 15% of the individuals were EOSS 1, a proportion that decreased to only 8-5% in higher BMI classes.

Thus, the supposed ‘licence’ would in any case only apply to 1 in 6 overweight folks or even only 1 in 15-20 folks with a BMI over 30 – the vast majority would not be in this supposed ‘wait and see’ category.

Indeed, amongst individuals with Class II or III obesity, almost 80% of individuals were classified as EOSS 2/3 – this is the group that is very likely to benefit from obesity treatments.

As I’ve said before, EOSS adds important shades of grey to what many consider to be black or white – either you are at a ‘healthy weight’ (whatever that is) or you need to lose weight – whether or not you are actually healthy at your current weight does not appear to enter into their reasoning.

Of course, when there is money to be made in weight loss, and when most of your clients happen to be EOSS 0, our studies suggest that you should perhaps consider changing your business model (or at least have your clients sign a consent form stating that losing weight may not be in their best interest).

But if you are a health professional or decision maker wondering about just how to dedicate your limited resources to those obese patients most likely to benefit, first addressing the needs of those presenting with higher EOSS stages seems a perfectly rational and reasonable argument.

Only if you still believe that health can be measured simply by stepping on a scale, are you likely to continue thinking that EOSS is a disservice to medical care and dangerous to the public.

For the rest of us, hopefully, EOSS will prove a viable strategy to deliver evidence-based health care to where it is needed the most.

Ottawa, Ontario

Padwal RS, Pajewski NM, Allison DB, & Sharma AM (2011). Using the Edmonton obesity staging system to predict mortality in a population-representative cohort of people with overweight and obesity. CMAJ : Canadian Medical Association journal = journal de l’Association medicale canadienne PMID: 21844111

Kuk JL, Ardern CI, Church TS, Sharma AM, Padwal R, Sui X, & Blair SN (2011). Edmonton Obesity Staging System: association with weight history and mortality risk. Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme PMID: 21838602