Obesity medicine, which I define as the medical care of someone living with obesity, should approach patients holistically with the aim of improving their overall health and well-being. Advice to lose weight may or may not be part of obesity management – much can be gained for someone living with obesity by promoting their health behaviours, getting them to feel better about themselves, improving their mental health, and helping them better managing their health issues. Much of this can be achieved with no or very little weight loss.
Thus, we must consider the question of when weight loss would specifically need to be part of the treatment objectives.
In my own practice, I approach this problem by considering the following three questions:
- Is this a problem unrelated to abnormal or excess body weight?
- Is this a problem aggravated by abnormal or excess body weight?
- Is this a problem caused by abnormal or excess body weight?
From what I hear from my patients, the most common mistakes in medical practice fall into the first group – trying to address unrelated issues with weight loss recommendations. There are endless stories of patients going to see their health provider with problems clearly unrelated to their body fat (e.g. a broken arm, a sore throat, the flu, depression, migraines, etc.), who simply get told to lose weight. Indeed, there is evidence to suggest that patients with obesity are less likely to undergo diagnostic testing, most likely based on the assumption that their problems are simply related to their excess weight. This is not only where grave medical errors can be made (late or misdiagnosis), but also where the advice to lose weight is clearly wrong. If the presenting problem has nothing to do with excess weight, then no amount of weight loss will fix it.
The second category deals with issues that are not causally related to abnormal or excess body fat but where the underlying problem either causes more symptoms or is more difficult to treat because of the patient’s size or fat distribution. There are countless medical problems that fall into this category. For e.g. a heart or respiratory problem entirely unrelated to excess weight (e.g. a valvular defect or asthma) can become worse, cause more symptoms, or be much more difficult to treat simply because of the patient’s size. This group also includes issues like neck or joint pain from a trauma (e.g. a motor vehicle or skiing accident), reflux disease (e.g. from a hiatal hernia), urinary incontinence (from multiple child births), etc., etc., etc. – the list is long. Here, although obesity has nothing to do with the underlying problem, weight loss may alleviate the symptoms or at least make them more manageable (they are however unlikely to be fully resolved). These patients present with what may be described as a relative or “secondary” indication for weight loss. Of course, if there are viable treatments options for the primary problem, then this is where the emphasis should be. Weight loss can best be considered as “second-line” treatment. It would be completely unethical to withhold effective treatment for the underlying problem just because of the patient’s size (as in, “no treatment for you until you lose X lbs!”)
Finally, we have the third category of health issues that are directly causally linked to the excess weight – in most cases, the problem did not exist prior to weight gain and losing weight is often likely to completely resolve the problem (unless the patient has already sustained irreversible organ damage). This group of health issues not only includes the vast majority of cases of type 2 diabetes, hypertension, obstructive sleep apnea, fatty liver disease, infertility, etc. but also all of the functional limitations that people may experience simply because of their excess body fat. This is the only category of patients who would be deemed to have a “primary” indication for weight loss. Losing the weight literally solves their problem. Indeed, trying to manage the problem without weight loss is nothing less than “palliative” care. This is not to say that weight loss will always guarantee success even if the underlying problem is directly related to excess weight. For e.g. although there is ample evidence that excess weight is a prime risk factor for gall bladder disease, (rapid) weight loss may actually promote formation of gall stones. Similarly, although intertrigo (skin fold infections) can occur as a direct consequence of excess weight (e.g. chaffing), losing weight may actually make the problem worse by deepening the skin folds. Thus, even in this category, one needs to carefully consider risk-benefit ratios.
Of course, any recommendation to lose weight must take into account the complex nature of obesity in the first place and the fact that long-term weight-loss maintenance will require an approach (behavioural, medical, or even surgical) that takes into account the chronic relapsing nature of this disorder. Simply telling people with obesity to “eat less and move more” is about as medically sound and effective, as simply telling people with depression to “cheer up”.
Both, to avoid grave medical errors and to not insult their patients, I strongly recommend that medical practitioners first approach all their patients with obesity based on the assumption (that their presenting health issues are unrelated to their excess weight) before considering possibilities two (unrelated but aggravated) and three (causal). Advise to lose weight has no role in situation 1, can be considered in situation 2, and is clearly the best course of action for situation 3.
In the same manner in that there is not one predisposing factor for the development of obesity, the phenotypic clinical presentation of obesity is likewise extraordinarily heterogenous. (This has some authors speaking of “obesities” rather than “obesity”).
While it is now well established that BMI is a measure of size rather than health, it is perhaps less well recognised how the different types of body fat and their storage in various fat depots and organs can contribute to cardiometabolic disease (location, location, location!).
Now, a comprehensive review by Ian Neeland from the University of Texas Southwestern Medical Center, Dallas, together with my colleagues Paul Poirier and JP Despres from Laval University in Quebec, published in Circulation discusses the cardiovascular and metabolic heterogeneity of obesity.
As the authors point out,
“Although the BMI has been a convenient and simple index to monitor the growth in obesity prevalence at the population level, many metabolic and clinical studies have revealed that obesity, when defined on the basis of the BMI alone, is a remarkably heterogeneous condition. For instance, patients with similar body weight or BMI values have been shown to display markedly different comorbidities and levels of health risk.”
Not only has BMI never emerged as a significant component in risk engines such as the Framingham risk score, there are many individuals with obesity who never develop metabolic complications or heart disease during the course of their life.
The paper offers a good review of what the author describe as adipose dysfunction or “adiposopathy” = “sick fat”. Thus, in some individuals, there is an accumulation of “unhealthy” fat (particularly visceral and ectopic fat), whereas in others, excess fat predominantly consists of “healthy” fat (predominantly in subcutaneous depots such as the hips and thighs).
The authors thus emphasise the importance of measuring fat location with methods ranging from simple anthropometric measures (e.g. waist circumference) to comprehensive imaging techniques (e.g. MRI).
The authors also provide a succinct overview of exactly how this “sick fat” contributes to cardiometabolic risk and briefly touches on the behavioural, medical, and surgical management of patients with obesity and elevated cardiometabolic risk.
I, for one, was also happy to see the inclusion of the Edmonton Obesity Staging System in their reflections on this complex issue.
This paper is certainly suggested reading for anyone interested in the link between obesity and cardiovascular disease.
The European Association for the Study of Obesity (EASO) had now released the new OMTF guidelines Practical Recommendations of the Obesity Management Task Force of the European Association for the Study of Obesity for Post-Bariatric Surgery Medical Management.
The guidelines provide the latest guidance on nutritional management, micronutrient supplementation, managing co-morbidities, pharmacotherapy, psychological management, and prevention and management of weight regain. The guidelines also address the issue of post-bariatric surgery pregnancy.
Not covered are issues related to dealing with excess skin and rehabilitation (e.g. return to work, reintegration in social activities, education, etc.), both of significant importance, especially in people with severe obesity.
As the authors note,
“Bariatric surgery is in general safe and effective, but it can cause new clinical problems and it is associated with specific diagnostic, preventive and therapeutic needs. Special knowledge and skills of the clinicians are required in order to deliver appropriate and effective care to the post-bariatric patient. A post-bariatric multidisciplinary follow-up programme should be an integral part of the clinical pathway at centres delivering bariatric surgery, and it should be offered to patients requiring it”
These guidelines are now available open access in Obesity Facts.
The 2018 JAMA special issue on obesity also includes a brief paper by Ann Blair Kennedy and colleagues reviewing the debate (which really isn’t much of a debate to anyone who knows the data) on whether it is more important to be fit than to worry about being fat (it is).
As the authors review, there is now ample data showing that cardio-respiratory fitness (CRF) is far more important for the prediction of cardiovascular mortality than the level of fatness (measured as BMI or otherwise).
In fact, once you account for differences in “fitness”, actual BMI levels almost cease to matter in terms of predicting longevity.
Unfortunately, as the authors point out, most studies linking obesity to cardiovascular outcomes (including studies on the so-called obesity “paradox”), fail to properly measure or account for cardiovascular fitness, thereby ignoring the most important confounder of this relationship.
For clinicians (and anyone concerned about their excess weight), it is helpful to remember that while achieving and maintaining a significant weight loss is a difficult (and often futile) undertaking, achieving and maintaining a reasonable degree of cardiorespiratory fitness is possible at virtually any shape or size.
Thus, as the authors point out,
“…in current US society, many people progressively gain weight and lose CRF as they age. Conceivably, maintaining CRF may be more important than preventing the development of obesity. However, for people who are overweight or have mild to moderate obesity, there are effective ways to improve CRF, including exercise and lifestyle interventions and there is general agreement that having low levels of PA is unhealthy. Increasing PA to help keep individuals from becoming unfit can be achieved if patients meet current PA guidelines of 150 minutes of moderate or 75 minutes of vigorous PA per week.”
Clearly, if your primary concern related to your patients’ excess body fat is about their cardiovascular health, you would probably be doing them a far greater service by getting them to improve their cardiorespiratory fitness rather than simply lose a few pounds (and no, exercise is not the best way to lose weight!).
On the other hand, if there are other health issues that are of primary concern (e.g. sleep apnea, osteoarthritis, fatty liver disease, etc.) or the degree of excess fat significantly affects mobility or other aspects of quality of life, then perhaps a frank discussion about available and effective “weight-loss” treatments appears warranted.
Let us not forget that it is never a good idea to simply treat numbers on the scale.
Another series of articles in the 2018 JAMA special issue on obesity, deals with the impact of bariatric surgery on health outcomes and overall mortality.
The first article by Sayeed Ikramuddin and colleagues is an observational follow-up of a randomized clinical trial at 4 sites in the United States and Taiwan, involving 120 participants who had a hemoglobin A1c(HbA1c) level of 8.0% or higher and a BMI between 30.0 and 39.9. The study compared intensive lifestyle and medical management intervention based on the Diabetes Prevention Program and LookAHEAD trials for 2 years, with and without (60 participants each) Roux-en-Y gastric bypass surgery followed by observation to year 5.
At 5 years, 13 participants (23%) in the gastric bypass group and 2 (4%) in the lifestyle-intensive medical management group had achieved the composite triple end point (HbA1c less than 7.0%, LDL cholesterol less than 100 mg/dL, and systolic blood pressure less than 130 mm Hg).
In the fifth year, 31 patients (55%) in the gastric bypass group vs 8 (14%) in the lifestyle–medical management group achieved an HbA1c level of less than 7.0%.
As is to be expected, surgical treatment resulted in more serious adverse events (66 vs 38 events), most frequently involving gastrointestinal and surgical complications such as strictures, small bowel obstructions, and leaks.
A second study by Gunn Signe Jakobsen and colleagues from Norway, reports on changes in obesity related comorbidities in patients with severe obesity (BMI ≥40 or ≥35 and at least 1 comorbidity) undergoing bariatric surgery (n=932, 92 gastric bypass) or specialized medical (“lifestyle”) treatment (n=956) at a tertiary care outpatient center.
Based on drugs dispensed according to the Norwegian Prescription Database and data from the Norwegian Patient Registry and a local laboratory database, surgically treated patients had a greater likelihood of remission (RR, 2.1) and lesser likelihood for new onset of hypertension (RR, 0.4), a greater likelihood of diabetes remission (RR, 3.9) but also a greater risk of new-onset depression (RR, 1.5) and treatment with opioids (RR, 1.3.
Again, as expected, surgical patients had a greater risk for undergoing at least 1 additional gastrointestinal surgical procedure (RR, 2.0).
From these findings the researchers conclude that adding gastric bypass to lifestyle and intensive medical management alone in patients with severe obesity and type 2 diabetes, there remained a significantly better composite triple end point in the surgical group at 5 years.
The third study by Orna Reges and colleagues from Israel, was a retrospective cohort study in a large Israeli integrated health fund database, that compared 8,385 patients who underwent bariatric surgery compared to 25,155 nonsurgical patients matched on age, sex, BMI, and diabetes. The surgical interventions included laparoscopic banding [n = 3635], gastric bypass [n = 1388], and laparoscopic sleeve gastrectomy [n = 3362]
Over the approximately 4.5-year follow up period, there were 105 deaths (1.3%) among surgical patients compared to 583 deaths (2.3%) among nonsurgical patients.
Mortality rates were similar across the different types of surgery: [1.7%] who underwent laparoscopic banding, 18 [1.3%] gastric bypass, and 26 [0.8%] sleeve gastrectomy).
Form these findings the authors conclude that, compared with usual care, nonsurgical obesity management, was associated with lower all-cause mortality.
Finally, a fourth paper by Sarah Shubeck and colleagues from the University of Michigan, discuss the finding of a study by Anita Courcoulas and colleagues published in JAMA Surgery, which describes 7-year weight trajectories and health outcomes in the Longitudinal Assessment of Bariatric Surgery (LABS) Study that includes 1738 patients who underwent Roux-en-Y gastric bypass (RYGB) and 610 patients who underwent laparoscopic adjustable gastric banding (LAGB).
At 7 years, patients who had undergone RYGB lost 28% of initial weight with minimal weight regain between years 3 and 7 (3.9%) compared to patients who had undergone LAGB (14.9% weight loss with 1.4% regain).
Patients who had undergone RYGB benefitted from high rates of long-term relief from all 5 comorbidities evaluated (diabetes mellitus, high LDL cholesterol, high triglycerides, low HDL cholesterol level, and hypertension) at 7 years than those who had undergone LAGB.
Importantly, postprocedure mortality was very low with 3 deaths within 30 days of surgery and 7-year death rates of 3.7/700 person-years after RYGB (59 deaths) and 2.7/700 person-years after LAGB (15 deaths). Rates of operative revisions and reversals were low for patients in the RYGB group (0.92/700 person-years), but were significantly higher among patients in the LAGB group (30.29/700 person-years).
Taken together, all 4 studies document the considerable long-term health benefits associated with surgical treatment of severe obesity but also note that there are certain surgical risks (which vary between procedures) that need to be individually discussed with patients.