Dr. Sharma's Obesity Notes

So after yesterday’s CMAJ editorial, in which Yoni and I blasted some practices of commercial weight loss programs, created a flurry of media interest (including on the front page of the Globe & Mail as well as national TV), here is the best available sytematic review of commercial weight-loss programs in the US, published in the Annals of Internal Medicine by Tsai and Wadden from the University of Pennsylvania School of Medicine in 2005.

The authors reviewed company Web sites, conducted telephone discussion with company representatives, and searched the MEDLINE database.

All randomized trials of at least 12 weeks in duration that enrolled only adults and assessed interventions as they are usually provided to the public, or case series that met these criteria, stated the number of enrollees, and included a follow-up evaluation that lasted 1 year or longer were examined.

Programs studied included eDiets.com, Health Management Resources, Take Off Pounds Sensibly, OPTIFAST, and Weight Watchers.

Of 3 randomized, controlled trials of Weight Watchers, the largest reported a loss of 3.2% of initial weight at 2 years - this is very much in the same ball park as the long-term results of some of the best academically run behavioral programs. One randomized trial and several case series of medically supervised very-low-calorie diet programs (like OPTIFAST) found that patients who completed treatment lost approximately 15% to 25% of initial weight.

All programs were associated with high costs, high attrition rates, and a high probability of regaining 50% or more of lost weight in 1 to 2 years.

Commercial interventions available over the Internet and organized self-help programs produced minimal weight loss.

The authors note that because many studies did not control for high attrition rates, the reported results are probably a best-case scenario. Thus, with the exception of 1 trial of Weight Watchers, the evidence to support the use of the major commercial and self-help weight loss programs is suboptimal.

Nevertheless, programs like Weight Watchers (a member of the Edmonton WeightWise (WW) Community Network) or OPTIFAST (often used in WW as a rescue strategy in Stage 4 patients and also provided by a WW Community Network Partner) may be effective in some individuals and can be part of a long-term weight management strategy for selected patients.

However, clearly most commercial weight-loss programs (and products) have yet to be studied in large controlled trials.

So how are commercial programs different from ethical, evidence-based programs, such as Alberta Health Services’, Edmonton-based WW program? While we may still have high attrition rates and results that are in line with reported outcomes for behavioural, pharmacological and surgical trials (i.e. weight loss in the range of 5 to 35%) - at least we do not claim, advertise or sell services that are not based on best evidence.

In fact, a notable feature of the WW program is an orientation session that every patient has to attend before being seen in the clinic, which certainly leaves no doubt as to the challenges and limited magnitude of long-term weight loss that can be expected - for some patients just stopping the gain is success!

Furthermore, as befits an academic-based program, WW patients on the waiting list as well as those receiving medical and/or surgical treatment arms are being prospectively followed in a 3-year study funded by the Canadian Institutes of Health Research (APPLES).

We recognize that access to and options for obesity treatment are limited within the public health care system. However, this should not serve as an excuse to scam individuals challenged by excess weight out of their money by promising results that are inconsistent with the best evidence. WW does not recognize as Community Partners weight-loss programs, whose results are solely based on anecdotes or testimonials (always a Red Flag to watch out for).

AMS
Edmonton, Alberta

Today’s edition of the Canadian Medical Association Journal (CMAJ) features an editorial co-authored by Yoni Freedhoff (of Weighty Matters fame) and myself on the largely unregulated weight-loss industry that is often heavy on promises but light on evidence.

The reason we slam the often preposterous weight-loss claims is not because Yoni and I are against commercial enterprise - both of us make a living treating patients for obesity. The reason we wrote the editorial (together with the editorial team of CMAJ), is because we believe that patients, who present with a legitimate and potentially deadly and disabling chronic disease, should receive proper medical care based on the best available scientific evidence. We feel that the delivery of this care, not unlike care for other medical conditions, is best left in the hands of licensed and regulated health professionals. When regulated health professionals themselves engage in pseudoscience, it is up to the colleges and professional bodies to step in and ensure that obesity care is delivered in an ethical and professional manner with due regard to best evidence.

Indeed, there are numerous “private” centers and practicing health professionals that offer a wide range of credible, ethical and evidence-based obesity treatments - many of these can be found among the extensive Weight Wise Community Network.

Much of the confusion about what works and what doesn’t is perhaps due to the mistaken notion that weight loss in itself is a measure of success. As I always remind my patients, it never matters how much you lose, only how much you can keep off.

Unfortunately, while most patients expect to lose (and keep off) half their weight, even surgery on average only delivers around 30% long-term weight loss.

The idea, that results rivaling or even exceeding those seen with bariatric surgery can be achieved by simply taking a “natural” product bought off a super market shelf or the internet, which promises to help you shed pounds by “cleansing” your body or “boosting” your metabolism (all with no side effects and without having to move a muscle), is simply preposterous. Believe me, if such a product existed, I’d be the first to prescribe it to my patients.

The sad reality is that there is no “magic” solution - long-term weight management requires strict control of energy balance - best achieved by careful adjustment of dietary caloric intake combined with increased activity. Yes, at times, prescription drugs, low-calorie diets, or even surgery will be necessary - but even these are not magical cures - just evidence-based treatments for the chronic medical condition called obesity.

The following is a simple consumer guide to recognizing fraudulent weight loss products:

Mistrust any product that claims to

- cause weight loss of two pounds or more a week for a month or more without dieting or exercise

- cause substantial weight loss no matter what or how you eat

- cause permanent weight loss (even when you stop using product)

- safely enable consumers to lose more than three pounds per week for more than four weeks

- cause substantial weight loss for all users

- cause substantial weight loss by wearing it on the body or rubbing it into the skin

For a comprehensive document on how to recognize fraudulent products from the US Bureau of Consumer Protection click here. You may also want to check out the add for “Fat Foe” at the head of this post.

Incidentally, the CMAJ editorial is accompanied by an article on Yoni’s remarkable private collection of “Believe it or Not”-style weight-loss treatments - these indeed need to be seen to be believed. Additional photographs of preposterous weight-loss products can be found on the CMAJ website.

I am certain that this CMAJ editorial will cause a stir in the media - will it stop people from spending their money on useless diet aids and weight-loss gizmos - hardly.

AMS
Edmonton, Alberta

The remarkable metabolic benefits seen with gastric bypass surgery are believed to be in large part due to the fact that food, which is rerouted as a result of the surgery, no longer comes in contact with the duodenum and early part of the ileum, thereby changing the pattern of incretin secretion.

A new device, designed to mimic this surgery is currently in development. The endoscopically insertable device is called EndoBarrier and is being developed by GI Dynamics, a Lexington, Massachusetts company.

A recent GI Dynamics press release describes the EndoBarrier as follows:

“The EndoBarrier creates a physical barrier between ingested food and the intestinal wall, which physicians believe, may change the metabolic pathway by controlling how food moves through the digestive system. This mechanical bypass of the small intestine is thought to mimic the effects of gastric bypass surgery on a patient’s metabolism, potentially resulting in weight loss and remission of type 2 diabetes. The EndoBarrier can be implanted and removed endoscopically (via the mouth) with relative ease and without the need for surgical intervention or alteration of the patient’s anatomy.”

Regarding preliminary results, GI Dynamics has the following to say:

“To date, more than 100 patients have received the EndoBarrier in clinical trials. In September 2008, GI Dynamics announced data from a multi-center, randomized clinical trial of 37 patients suggesting that the EndoBarrier is well-tolerated with promising short-term weight loss results in morbidly obese patients. These data showed that 26 patients treated with the EndoBarrier lost on average, triple the weight of their diet control group (11 patients). Specifically, at just 12 weeks, the device group lost 13.7 kg (30.2 lbs) versus 4.4kg (9.7 lbs) for the control group. Also notable was evidence that a beneficial effect on type 2 diabetes was observed through lower blood glucose levels and/or a reduction in diabetic medication.”

Overall, certainly a novel idea. Obviously, we need to await the results of the ongoing trials and I can already guess that this is probably not going to work for everyone.

Nevertheless, if it delivers what it promises, certainly an alternative to surgery, especially for individuals with moderate obesity in whom the primary indication is diabetes.

AMS
Edmonton, Alberta

Capsinoids or non-pungent extracts from chilli plants have been shown to have thermogenic effects on metabolism and reduce body weight in animals. Indeed, many commericial weight loss pills contain such extracts.

But how relevant are these effects?

This question was recently addressed by Soren Snitker and colleagues from the University of Maryland, Baltimore, MD, USA, in a study just published in the American Journal of Clinical Nutrition.

Snitker et al. conducted a 12-wk, placebo-controlled, double-blind, randomized study of oral capsinoids (6 mg/d) in 40 men and 40 women. They measured changes in body weight, body fat (DEXA) and metabolism (indirect calorimetry). They also performed some genetic analyses.

Capsinoids were well tolerated but did not markedly affect body wieght (0.9 kg on capsinoids vs. 0.5 kg on placebo). Total body fat was unchanged but there was a marginal (1.1%) reduction in abdominal adiposity with capsaicin. While changes in resting energy expenditure did not differ between groups, fat oxidation was a tick higher at the end of the study in the capsinoid group. Of 13 genetic variants tested, TRPV1 Val585Ile and UCP2 -866 G/A correlated significantly with change in abdominal adiposity.

Although the authors appear quite enthusiastic about their findings, I consider this essentially a negative study. Neither the few grams of weight loss nor the skimpy increase in fat oxidation are likely to be of any clinical relevance. The study is vastly underpowered for any meaningful genetic analyses.

I will certainly continue enjoying my hot sauce - but will stop kidding myself that this indulgence in anyway contributes to managing my weight.

AMS
Edmonton, Alberta

Well, not quite! Yesterday EnteroMedics announced the first 18-month results of their VBLOC-RF2 Feasibility Study.

This treatment involves blockade of vagal activity via an implantable electronic system (Maestro System) that delivers high frequency, intermittent low energy electrical signals through laparoscopically implanted leads. Blockade of vagal signals has been shown to reduce hunger, increase satiety and possibly have neuro-endocrine effects on liver and pancreas.

The still ongoing feasibility study includes 38 implanted subjects and shows excess weight loss (EWL) of 37.6% in 9 patients at 18 months, 28.1% in 17 patients at 12 months and 17.9% in 35 patients at six months of therapy. In line with the weight loss, improvements were also noted in diabetes and hypertension. No deaths or unanticipated adverse device events have been reported.

While the results are promising, it is important not to get misled by the reporting of EWL (a rather dubious construct generally reserved for surgical weight loss studies that describes loss of “excess” weight rather than absolute weight loss). The EWL, when translated to percent initial weight loss is generally far more modest (probably around 8-12%) but still at the higher end of what has been achieved with medical obesity treatments. It does however fall short of what is generally seen with obesity surgery (around 20-30% loss of initial weight). 

Nevertheless, given our rather limited range of treatments for obesity, the results are clearly reason for some optimism. A much larger (n=294) randomized, prospective, double-blind, placebo-controlled study (EMPOWER) is currently being conducted in the United States and Australia is expected to report in the second half of this year.

AMS
Edmonton, Alberta