Calories are the currency of weight management and any weight loss diet has to offer fewer calories than the body needs.

However, the means by which this caloric deficit is best achieved remains an area of continuing debate. While the proponents of ketogenic low-carb diets cite the greater ease of lowering weight, proponents of low-fat diets extol the putatively greater benefits on lipid profiles.

Nevertheless, previous studies have clearly shown that in the end both strategies lead to the same amount of weight loss, even if the low-carb approach may initially seem more effective.

This observation is once again confirmed in a new study by William Yancy Jr and colleagues from the Veterans Affairs Medical Centre, Durham, NC, published in the latest issue of the Archives of Internal Medicine.

In this study 146 overweight or obese outpatients (mean age 52 yrs) were randomized to either a ketogenic low-cab diet (initially <20 g of carbohydrate daily) or the lipase inhibitor orlistat (120 mg TID) combined with a low-fat diet (<30% energy from fat, 500-1000 kcal/d deficit) over 48 weeks.

Of the initial participants, 79% completed the low-carb arm whereas 88% completed the orlistat plus low-fat diet. Weight loss was similar between the groups, with participants losing around 9% of their initial body weight on either diet.

While the low-carb diet appeared to have a more beneficial impact on blood pressure, the orlistat low-fat combination appeared to have a greater beneficial impact on LDL-cholesterol.

However, in the end it is probably fair to say that both approaches led to more or less similar improvements in body weight and related risk measures, showing once again that this is probably not so much about which diet is more effective as it is about which diet works best for you.

Thus, in clinical practice it is likely that some patients will find it easier and preferable to severely restrict their carb intake, while others may find it easier to reduce their calories from fat by taking orlistat and reducing the fat in their diet.

The bottom line in both case is that the benefits will only persist as long as the participants stay on their respective diets or treatments. This makes it even more critical that patients chose the strategy that works best for them and that they are most likely to stay on in the long term.

Remember, neither diet is likely to “cure” obesity. As with all obesity treatments, when the interventions stop the weight comes back.

AMS
Edmonton

Yesterday’s post was about how we need to rethink and restructure obesity management in primary care. Today I discuss a primary care study that describes the outcome of non-surgical weight management in patients with extreme obesity.

The paper by Donna Ryan and colleagues published in this week’s edition of the Archives of Internal Medicine describes the results of the Louisiana Obese Subjects Study (LOSS), a 2-year randomised, controlled, “pragmatic clinical trial” conducted in seven primary care practices and one research clinic.

Around 600 Volunteers with BMIs in the 40-60 range were screened and randomized to intensive medical intervention (IMI) (n = 200) or usual care (UCC) (n = 190). The IMI group recommendations included a 900-kcal liquid diet for 12 weeks or less, group behavioural counseling, structured diet, and choice of pharmacotherapy (sibutramine, orlistat, or diethylpropion) during months 3 to 7 and continued use of medications and maintenance strategies for months 8 to 24. In contrast, the UCC group received guidance in an internet weight management program.

The mean age of participants was 47 years; 83% were women, and 75% were white. Retention rates over two years were 51% for the IMI group and 46% for the UCC group. After 2 years, 31% in the IMI group achieved a 5% or more weight loss and 7% achieved a 20% weight loss or more, compared with 9% and 1% of those in the UCC group. A total of 101 IMI completers lost an average of –9.7% of their initial weight whereas weight in the 89 UCC completers remained virtually unchanged (which over 2 years is actually not such a bad result at all - remember, successful weight management starts with stopping the gain!).

While the study can no doubt be criticized for high attrition rates and relatively modest weight loss in IMI completers (only around 10% of initial weight), the study does show that at least for some patients, aggressive management strategies in primary care may provide sustainable outcomes that can have clear health benefits.

Let us not forget that attrition rates in disease management programs for other chronic diseases (e.g. diabetes, dysplipidemia, hypertension, etc.) are also relatively high and that only a minority of patients with these other common chronic conditions are ever fully controlled in primary care practice (despite the wide range of medical treatments and resources available to patients with these conditions).

Thus, there is no reason to believe that chronic disease management for obesity, when implement in primary practice, must necessarily fare worse than chronic disease management for other conditions. The fact that obesity management in primary practice appears so unsuccessful is not because interventions don’t work (this study shows they do), but rather because no serious attempt is made to address obesity in the first place.

While the 900-calorie liquid diet followed by intense behavioural and pharmacological treatment may not be everyone’s cup of tea, and of course comes nowhere near the results with bariatric surgery, for some patients this is may well be a safe and cost-effective strategy that can be delivered in primary practice.

Remember, in obesity treatment, one size certainly does not fit all and having a breadth of strategies rather than a single intervention is probably the only way to go.

I would certainly like to hear from anyone who has been on a 900-kcal liquid diet or who uses this approach in their patients.

AMS
Edmonton, Alberta

As report after report expresses concern about the rising prevalence and health impacts of obesity, it is becoming increasingly clear that business as usual is not going to work in addressing this epidemic.

Regular readers will recall the recent WHO/OECD analysis, which concluded that it will take decades for prevention efforts to show any sign of reversing the epidemic. This means that millions of North Americans will need obesity treatments, whether behavioural, pharmacological, or surgical.

Given the sheer numbers, much of this treatment will need to be delivered in primary care - and herein lies the problem. Can primary care deliver what is needed?

In an editorial published in this week’s issue of the Archives of Internal Medicine, my friend and colleague Robert Kushner (past President of The Obesity Society and co-author of our paper on the Edmonton Obesity Staging System) questions whether primary care is up to this challenge.

Despite all recommendations and guidelines, obesity is underrecognized and undertreated in US primary care. The US National Ambulatory Medical Care Survey (NAMCS) estimated that obesity-related counseling occurred in only around 25% of visits and the rates are declining.

According to Kushner, “The reasons for the gap are complex owing to multiple physician, patient, and medical system factors. Barriers include a lack of reimbursement, limited time during office visits, lack of training in counseling, competing demands, low confidence in the ability to treat and change patient behaviors, limited resources, the perception that patients are not motivated, and a paucity of proven and effective interventions to treat obesity.”

Obesity treatment is often perceived by physicians as a daunting or even futile task. In addition, stigmatization of the patient may pose a major barrier.

As Kushner sees it, at least two changes are needed to engage PC physicians in obesity care: systematic reorganization of office-based processes and physician training in obesity care.

Not only must obesity be addressed in the same manner as other chronic diseases, but PC physicians need to acquire skills to work with multidisciplinary care teams (nurse practitioners, registered dietitians, health psychologists, and exercise specialists), as well as obtain a reasonable knowledge of the principles of diet, physical activity, and obesity care.

In summary, nothing that regular readers of these pages will not have heard from me before.

Although the article focusses on the US, there is not the slightest indication that the situation in Canada is any different.

As I have said before, obesity management belongs in primary care - it needs to be managed with the same enthusiasm, resources and perseverance as other chronic diseases

Not treating obesity when obesity is the problem, is simply palliative care.

AMS
Edmonton, Alberta

Yesterday the news wires were swamped with reports on a new recommendations by the U.S. Preventive Services Task Force to screen school kids for obesity:

“The USPSTF recommends that clinicians screen children aged 6 years and older for obesity and offer them or refer them to intensive counseling and behavioral interventions to promote improvements in weight status.“

The recommendation appears largely based on a paper by Evelyn Whitlock and colleagues who performed a systematic review on the effectiveness of weight management interventions in children just published in Pediatrics. The review concludes that despite important gaps, available research supports at least short-term benefits of comprehensive medium- to high-intensity behavioral interventions in obese children and adolescents.

In their recommendations, the USPSTF includes the previous American Medical Association Expert Committee recommendation on childhood obesity, namely to use

“a stepwise approach that divides treatment into several stages including counseling, providing a structured weight management plan, and using a comprehensive multidisciplinary intervention/ tertiary care intervention delivered by multidisciplinary teams with expertise in childhood obesity.“

So the recommended response to a “positive” screen is not 20 extra minutes of phys-ed per day or sitting through a class on healthy eating; no, the recommended response to a “positive” screen is comprehensive medical and behavioural intervention by a multidisciplinary team with expertise in childhood obesity…

…and herein lies the problem!

How many overweight and obese kids will actually have access to this kind of multidisciplinary weight management?

Indeed, it is only too easy to screen kids, label them as overweight or obese, and thereby destroy whatever is left of their self-esteem while amplifying their existing body-image concerns. Screening can probably also also point fingers and help heap blame on the parents, who may or may not be able to deal with these results in a constructive fashion.

Nowhere in the recommendations do I see any concern expressed about how these screening recommendations could possibly affect weight-bias and discrimination, have the potential to promote weight-based bullying and teasing, or result in potentially devastating outcomes including setting the poor kids off on unsustainable weight-loss attempts and weight cycling.

As I have blogged before, there is increasing evidence that weight bias and discrimination can increase depression and unhealthy eating behaviours - blame and ridicule has never been a good motivator for lifestyle change.

While I am as concerned as the next guy about the catastrophic increase in childhood obesity, I do not for a minute believe that screening and labeling 6 year-olds is the solution.

I can only imagine what some of my readers may have to say regarding this post.

AMS
Edmonton, Alberta

When the adipocyte-derived protein leptin was first discovered almost 20 years ago, it was touted as a possible “cure” for obesity. This idea never proved clinically effective with the exception of rare cases of genetic leptin deficiency.

However, as reviewed by Theodore Kelesidis and colleagues from Harvard Medical School, Boston, MA, in the latest issue of the Annals of Internal Medicine, there are a number of other interesting uses of leptin treatment that may well prove to soon be clinically relevant.

Thus, while circulating leptin levels certainly serve as a gauge of energy stores, thereby directing the regulation of energy homeostasis, neuroendocrine function, and metabolism, it appears that leptin’s physiological role is more as an indicator of energy deficiency, rather than energy excess.

Thus, decreases in leptin levels (as see with caloric restriction, weight loss, or loss of adipose tissue as in lipodystrophy) may mediate adaptation by driving increased food intake and directing neuroendocrine function to converse energy, such as inducing hypothalamic hypogonadism to prevent fertilization (as seen with anorexia or excessive exercise).

Currently a number of studies are exploring the role of leptin (particularly long-acting leptin homologues, e.g. metreleptin) in helping prevent weight regain in patients with intentional weight loss.

Replacement of leptin in physiologic doses also restores ovulatory menstruation in women with exercise-induced hypothalamic amenorrhea and improves metabolic dysfunction in patients with lipoatrophy, including lipoatrophy associated with HIV or highly active antiretroviral therapy.

Thus, although leptin treatment may not be an effective way to promote weight loss, it may well prove to have a number of clinical applications that may be relevant to weight management and treating the complications of excessive weight loss or lipodystrophy.

AMS
Edmonton, Alberta