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Get fat, live longer???

Friday, July 31, 2009 Author: Travis Saunders 11 Responses


If you follow obesity research with even a passing interest, there is a good chance that you have seen the now infamous editorial by Margaret Wente which was published in the Globe and Mail earlier this week.  In her editorial, Ms Wente describes a recent study in Obesity which examined the links between body mass index and mortality in a group of 12,000 Canadians.  Ms Wente makes several arguments - many of which are completely refuted by the available evidence - and I think that both her editorial and the study itself deserve some further analysis.

The study, which was led by Statistics Canada researcher Heather Orpana, reported that individuals who were overweight in 1994 were at significantly decreased risk of mortality over the 12-year follow-up when compared to individuals in the normal weight category.  Now for several reasons that I will get to in a moment, that isn't actually all that shocking. But I can see why it would seem pretty earth-shattering to people unfamiliar with the field of obesity research, which apparently includes Ms Wente.  You see, Ms Wente takes these findings to suggest that people should "Get fat, live longer".  Now of course Orpana and colleagues did not examine whether gaining weight makes people live longer - they only looked at the associations between baseline weight and mortality.  But that's not the biggest detail that Ms Wente overlooked.  In fact, she says that 

“being obese was associated with a 12-per-cent lower risk of dying”

But you see, the study didn't show that at all.  In fact, the Globe published a letter to the editor from the study authors on Wednesday correcting Ms Wente, saying that

"None of the analyses reported in our paper...showed that obesity (a body mass index ranging between 30 and 35) was associated with lower mortality."

Ouch.  

Let's get back to Ms Wente's argument that people should gain weight to live longer.  To support her point, she cites an Annals of Internal Medicine review paper from 1993 which reported that individuals who gained a modest amount of weight as they aged had the lowest risk of mortality, while those who lost a large amount of weight had a dramatic increase in mortality.  But the majority of studies in that review article failed to control for "unintentional" weight loss due to underlying cancer or other serious diseases (some did control for heart disease, however).  This means that they lumped unintentional weight loss due to disease with "intentional" weight loss due to lifestyle changes.  Unintentional weight loss is almost always bad, and may have been driving the relationship between weight loss and mortality in the Annals paper.  When we look instead at more recent research focusing on "intentional" weight loss in overweight and obese adults, we see an overwhelming majority of studies which report that weight loss actually reduces the risk of mortality, just as we would expect.  For example, a study in the American Journal of Epidemiology reports that "[in overweight women] intentional weight loss of any amount was associated with a 20% reduction in all-cause mortality". Why Ms Wente chose to avoid the wealth of current research in favour of a review article with such a major limitation I am not sure. If I had to guess, I would say it was because the majority of current research completely refutes her argument.

Now let's return to the current study in Obesity, because it is a genuinely interesting paper.  As I mentioned earlier, the study assessed the association between body mass index and mortality in a sample of 12,000 Canadians.  I've been chatting with a lot of people about this paper the past few days so I'd like to outline what I think we can learn from it.

The main point I would take from this paper is that body weight is associated with health risk, and as usual, it was a J shaped curve with increased risk observed at both very high and very low BMI's.  So as usual, you want to avoid being significantly over or underweight.  However, the reason that this study is so interesting is the nadir of the curve fell in the "overweight" range, rather than the "normal" range.  But when seen in the context of other research, that finding isn't all that surprising.  For example, Flegal and colleagues reported similar results in an American sample in 2005, as have some (but not all) others.  In fact, I don't think anyone knows for certain what the "ideal" BMI is, and it is almost certainly different for people of different genders and ethnic backgrounds (for example Asian individuals often begin to experience metabolic complications at much lower BMI's than Caucasians). The current BMI guidelines may be a bit conservative for Caucasians, but public health guidelines should err on the conservative side, especially in a country with a wide range of ethnic backgrounds like Canada.

It is also important to keep in mind that where you store body fat is probably more important than how much body fat you have. For example, body fat stored in the legs has consistently been shown to protect against metabolic risk in longitudinal studies. In contrast, abdominal fat, and in particular visceral fat, is independently associated with increased risk of morbidity and mortality. People who have high BMI’s tend to have high amounts of visceral fat, which is probably responsible for much of the relationship between BMI and health risk. However, some people with high BMI’s store body fat mainly in their lower body (the “pear” body shape), and these individuals often have very little metabolic risk at all. Similarly, although less common, some individuals with a high BMI are merely very muscular (these people also have low health risk).

We also know that when people exercise, they preferentially reduce the visceral fat that is responsible for much of the obesity-related health risk.  Even when there is little or no change in body weight, chronic exercise results in decreased visceral fat, and decreased health risk.  This is likely one reason why research has consistently shown that it is better to be overweight and physically active, rather than lean and inactive.

This means that if you are exercising regularly, even if you are not losing weight, you are still dramatically reducing your risk of diabetes, heart disease, and several types of cancer.  Too often people quit their exercise program because they feel they are not losing enough weight, or not losing weight fast enough, and they don't realize all of the benefits that come from exercise irrespective of changes in body weight.  So I hope this study helps people realize that they should focus on what matters - living a healthy lifestyle - and stop focusing so much on their body weight.

So what's the take-home message from this lengthy post (aside from ignoring health advice from Margaret Wente)?  Body weight affects your health, but not as much as diet and exercise.  So focus on those healthy behaviors, and you'll be moving towards a longer, healthier life.

Hat tips to Alex Green and Alex Hutchinson for sending me the Globe article and/or related links.  As always, to receive all of the latest obesity news and research via email, you can sign-up here.

Travis

Orpana, H., Berthelot, J., Kaplan, M., Feeny, D., McFarland, B., & Ross, N. (2009). BMI and Mortality: Results From a National Longitudinal Study of Canadian Adults Obesity DOI: 10.1038/oby.2009.191

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Erectile Dysfunction Today; Death Tomorrow?

Wednesday, July 29, 2009 Author: Peter Janiszewski, PhD 2 Responses
As I have previously discussed, while erectile dysfunction can have a detrimental impact on quality of life, it also appears to foreshadow future cardiovascular disease risk (i.e. heart attack). Indeed, it is reported that men who seek medical attention for cardiovascular disease symptoms often report that their penis stopped working long before they had any signs of heart problems.


A new study, published ahead of print in the Journal of Sexual Medicine, reports for the first time that the presence of erectile dysfunction independently predicts the future risk of death, particularly from cardiovascular disease.

In the study, a total of 1709 men aged 40-70 were assessed for erectile dysfunction at the beginning of the study and followed for an average of 15 years. At the end of the 15 year period, 403 of the men had died. The authors assessed the risk of mortality associated with having erectile dysfunction along with other known risk factors such as age, obesity, alcohol consumption, physical activity, smoking, hypertension, diabetes, and others.

After consideration of all these risk factors, men who had some degree of erectile difficulty had a 26% greater chance of dying from all causes and a 43% greater chance of dying from cardiovascular related causes.

Thus, it turns out that having erectile difficulties is as strong of a predictor of cardiovascular disease mortality as are other established risk factors such as obesity, hypertension, and diabetes.

As the authors point out, these findings may be clinically relevant so far as in many cases sudden death is the first manifestation of cardiovascular disease. In other words, we now have a new way to screen for cardiovascular disease related mortality, and thus intervene and hopefully prevent early mortality, whereas previously the first indication of the disease may have been death.

It is important to recall that while oral erectile dysfunction medication (Viagra, Cialis, and Levitra) may help with the erection issue, these medications are unlikely to reduce your risk of cardiovascular disease and mortality. The medication simply provides symptomatic relief meanwhile the underlying vascular disease process is allowed to progress further.

On the other hand, healthy changes in lifestyle can both improve the function of your penis, as well as your overall health. Indeed, a recent study I published earlier this year in the same journal documented that high levels of physical activity and a slim waistline are associated with better maintenance of erectile function, regardless of the level of obesity, as measured by body mass index.

So if your penis stops working today, there is a good chance you may have greater problems on the horizon. Rather than popping the blue pill, get off the couch and improve your dietary habits – your penis, your heart, and even your partner will thank you for it.

Peter

Araujo, A., Travison, T., Ganz, P., Chiu, G., Kupelian, V., Rosen, R., Hall, S., & McKinlay, J. (2009). Erectile Dysfunction and Mortality Journal of Sexual Medicine DOI: 10.1111/j.1743-6109.2009.01354.x

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Calorie Counts on Restaurant Menus - To Wait or not to Wait

Monday, July 27, 2009 Author: Travis Saunders 11 Responses
Image by Phototram.

Last week I came across a very interesting post on Marion Nestle's blog discussing the issue of posting calorie counts on restaurant menus, which has become a surprisingly controversial issue in recent years. For example, in 2008 the president-elect of The Obesity Society (an association of obesity researchers and practitioners which counts both Peter and I as members) was forced to resign following the backlash that erupted when he acted as a paid consultant arguing against a law requiring calorie counts on menus in New York City. Not exactly watergate, but a pretty big deal in the world of obesity research.

Many of us expect that if restaurants are forced to put calorie counts on their menus, they will probably avoid items that include outrageous amounts of calories (as Dr Nestle reports, anecdotal evidence suggests that this is already happening in California, where a recent law required that all fast food chains list calorie counts on their menus), while individuals are also likely to make healthier choices. The problem is that at present, there just isn't that much hard evidence to argue for or against placing calorie counts on menus. So while many of us think it's a logical step toward promoting healthier lifestyles, others argue that we should wait until we have more research.

This is where an interesting editorial by David Ludwig and Kelly Brownell in the Journal of the American Medical Association comes in. In it, Drs Ludwig and Brownell make the case that we should move towards calorie counts on menus now, rather than waiting for scientific certainty. The crux of their argument is this:

1. It is plausible that placing calorie counts on menus will help people reduce their caloric intake.
2. Although current evidence is limited, it appears to support the idea that calorie counts on menus reduce caloric intake.
3. The costs of this move are exceedingly small, since most fast-food restaurants have already calculated the nutritional information for all the items on their menu. The only "cost" is likely to be reduced sales of certain items, which the authors point out, is not a true cost from a public health perspective - in fact it's exactly what we want to happen!

I couldn't agree more. This debate is going to continue to rage on, but there just aren't many good reasons to delay putting calorie counts on menus, and the potential benefits vastly outweigh the potential costs. Placing calorie counts on restaurant menus is an idea whose time has come.

Travis



Ludwig, D., & Brownell, K. (2009). Public Health Action Amid Scientific Uncertainty: The Case of Restaurant Calorie Labeling Regulations JAMA: The Journal of the American Medical Association, 302 (4), 434-435 DOI: 10.1001/jama.2009.1045

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Active transportation: healthy but unsafe?

Friday, July 24, 2009 Author: Peter Janiszewski, PhD 7 Responses

This Wednesday I published an editorial in the Kingston Whig Standard in response to a recent story of a near-fatal accident of a local cyclist who was cut off by a truck while commuting to work (read the story here). See the editorial below:


The story of Brian Bowers’ near fatal cycling accident, along with the online comments to the story from members of the community, illustrate exactly why the Canadian Medical Association’s new policy on active transportation has no hope for adoption by the public, until such a time when attitudes towards cyclists, not to mention the ravaged Kingston roads, are overhauled.


Recently, the Canadian Medical Association released a policy statement recommending that “all sectors (government, business and the public) work together, as a matter of priority, to create a culture in their communities that supports and encourages active transportation.”

This policy statement is yet another attempt by the medical community to alleviate the growing rates of physical inactivity in Canada. Currently, three-quarters of Canadian adult men and women fail to meet the recommended 30 minutes of physical activity each day, and are thus deemed inactive.


Given that physical inactivity is a known contributor to obesity, diabetes, heart disease, cancer and multiple other health conditions, the health care cost of inactivity among Canadians approximates $4.3 billion each year.


Thus, in terms of personal health, the health of our community, and that of our overextended health care system, we all stand to gain much from adopting an active lifestyle.

One of the easiest ways to increase your level of daily physical activity is to use active modes of transportation, such as walking or cycling.

Before his devastating accident, Brian Bowers was one of only approximately 14% of Canadians who travel via active transportation. According to Statistics Canada, the remaining 86% of Canadians spend an average of 63 minutes every day commuting by automobile.


But is it really surprising that Brian Bowers was among a minority of active transporters?


When it comes down to it, how does one reconcile the potential personal health and environmental benefits of active transportation with the risk of serious injury or even death?


Most people, especially those not accustomed to the extreme cycling necessary to navigate the severely damaged roads, unyielding motorists, and jay-walking pedestrians common to Kingston, will opt for the relative safety of their car for transportation from point A to point B.
While the Canadian Medical Association’s policy statement suggests that communities must create an environment in which the “the physically active choice is the easy choice”, currently, the physically active choice in Kingston is anything but easy.


For one, bicycle theft in Kingston is all too common. It took only one week after my arrival in Kingston for my first bicycle to be stolen. Being a graduate student, it took some time before I could invest in another one.


Secondly, many streets are void of bike lanes and even when present are often being driven over or parked on by motorized vehicles. I have been personally cut off by vehicles while cycling in the bicycle lane on more occasions than I care to remember. Luckily, regular maintenance of my brakes and quick reflexes have thus far averted any serious injury.


In response to the above, the City of Kingston has just announced that it is working on the first phase of its “On-Road Bikeway Implementation Plan”, which aims to build a “dedicated cycling network in Kingston to encourage more Kingstonians to choose cycling as their mode of transportation.” The street locations of the cycling network and the specific work planned is outlined in detail on the city’s website.


While bike lanes can be painted overnight, attitudes are not so quick to change.


As well exemplified by the divided comments from the community on the Brian Bowers story, there is a lack of mutual respect between cyclists and motorists. Motorists perceive all cyclists to be untamed and reckless daredevils; meanwhile cyclists feel that many motorists are blood-thirsty cyclist hunters.


Since bicycles are legally considered to be equal to automobiles, cyclists must abide by all traffic regulations which apply to driving a car. On the other hand, motorists should understand the broad positive implications of active transportation by fellow members of the community, and encourage this activity by being courteous and accommodating to their pedaling peers.


Until mutual respect develops between cyclists and motorists, few Kingstonians will adopt habitual active transportation, no matter how many encouraging reports the medical community releases.


Have a great weekend,


Peter

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City of Ottawa Hikes Transit Fees for "Mature" Students - Will Physical Activity Drop as a Result?

Wednesday, July 22, 2009 Author: Travis Saunders 6 Responses
 Photo by Steph & Adam 

I received a disappointing email yesterday from a colleague pointing me to this article on transit fees in the City of Ottawa (where I currently live, work, and go to school).  The article describes a recent change which makes all students 28 and older ineligible for City of Ottawa "student" transit fares.  This will mean that many graduate students, medical students, and even "mature" undergraduate students will now have to pay the regular adult fare, which ads up to an extra $240/year.  According to this article on the Ottawa Citizen website "Council approved the change as a way to save money and balance the budget".  The city expects this change to bring in a meagre $220,000, but would cost many students more than half a month's rent over the course of a year.

The financial arguments against this move are pretty obvious.  Students - be they 18 or 28 - typically have little or no income.  There is absolutely no reason why a student in their 30's should have to pay a fee that a student in their early 20's does not. Whether they are in undergrad, grad school or med school, "mature" students face the same financial challenges as younger students, often more so (for example, older students are more likely to be supporting families of their own, and less likely to receive financial support from their parents).  But let's move away from the financial cost, and look at the bigger picture. 

Frequent readers of this blog will know that commuting by public transit is associated with increased amounts of physical activity. Earlier this year I interviewed Ugo Lachapelle, whose paper in the Journal of Public Health Policy suggested that individuals who use public transit are significantly more likely to reach the recommended amounts of daily physical activity than those who do not use public transit.  From a health perspective, it's really a no-brainer - people who take public transit tend to walk more than those who don't, which should place them at a lower risk for numerous chronic diseases.  That's why we have argued repeatedly here at Obesity Panacea that promoting transit use is a simple way to promote physical activity.  Of relevance to this discussion, in his Journal of Public Health Policy paper, Mr Lachapelle reported that 

"Having an employer-sponsored transit pass had a positive relationship with meeting the physical activity recommendation" 

I would consider a student transit pass to be nearly indistinguishable from  an employer-sponsored transit pass.  These programs make transit use more affordable, resulting in both more transit use, and increased levels of physical activity.  To me, this suggests that the opposite is also likely to be true - when the transit pass is no longer sponsored (or subsidized in this case) physical activity levels are likely to decrease.  This is not to mention the numerous other benefits of transit use, including reduced pollution and less traffic for those who do drive.  By increasing the fares that some students must pay, it makes it more likely that they will A) choose to forgo a post-secondary education, or B) commute by means other than public transportation, neither of which is good for the people of Ottawa.  

Interestingly, in our interview here on Obesity Panacea, Mr Lachapelle made the rather prescient statement that:

"Furthermore, there seems to be a lack of political will to address the question of commuter-related taxation, such as transit passes."

This is where you come in.  If you live in the City of Ottawa, you can find your city councillor by clicking here, while acting mayor Michel Bellemare's website can be found here.  I strongly urge you to write to them and explain why you feel this is bad decision for the City of Ottawa and its students.  If you live outside of Ottawa, please email acting mayor Bellemare directly by clicking here, and please spread the word via twitter, facebook, etc. I am writing my own letters as we speak.  Feel free to post a copy of your letter in the comments section below to encourage others.  Transit use and post-secondary education are simple things that we should all be promoting, and this policy does the exact opposite.

In case anyone is curious, I will not personally be hurt by this fee change - I'm 25, and with any luck I'll finish my PhD shortly after my 28th birthday :)  Thanks to Stephanie Prince Ware for emailing me and many others to let us know about this issue.

Travis

Lachapelle, U., & Frank, L. (2009). Transit and Health: Mode of Transport, Employer-Sponsored Public Transit Pass Programs, and Physical Activity Journal of Public Health Policy, 30 DOI: 10.1057/jphp.2008.52

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Massage post-exercise: aiding or imparing muscle recovery?

Monday, July 20, 2009 Author: Peter Janiszewski, PhD 3 Responses
Well, it turns out that Travis and I aren’t the only ones around here debunking myths in the health field. Queen’s University's own Dr. Michael Tschakovsky and graduate student, Vicky Wiltshire, have recently completed a study which seriously brings to question one popular claim made by massage therapists: that post exercise massage increases blood flow to the muscle, thereby aiding with recovery. The results of the study have yet to be published but have been presented at this year’s American College of Sports Medicine Conference, and since then Dr. Tschakovsky has been gracing the pages of various papers and magazines.

Dr. Tschakovsky is professor in the School of Kinesiology and Health Studies at Queen’s University who’s research aims to “understand the nature of mechanisms controlling blood vessels involved in adjusting exercising muscle blood flow and how disturbances and disease affect this control.” Both Travis and I have had the pleasure of taking Dr. T’s graduate course in cardiovascular control during exercise. As is evidenced by this study, as with much of his work, Dr. Tschakovsky craves to dispel myths in science and has fought against prevailing scientific dogma for most of his career. He is a true outside-the-box thinker, and is thus an inspiration to his students and others in the faculty (check his web page here). We are very pleased that he offered to answer a few questions regarding his recent research findings on the effects of massage on post-exercise muscle blood flow.

PJ: What is the origin of the popular misconception that massage increases blood flow?

Dr. T: Its difficult to say exactly. However, there was a study in the early 1950's that purported to observe large increases in blood flow in a massaged limb. There is some evidence also that skin blood flow may be elevated by massage. In speaking with massage therapists who believe it does increase blood flow, their comments are that it is obvious because the skin gets red after you push down on it. I think that for a long time the lack of evidence based practice perpetuated this misconception, and it is only recently that in some circles in the world of massage therapy it is being acknowledged that recent evidence does not support that misconception.

PJ: What parties were mostly perpetuating the popular notion that massage therapy is beneficial for exercise recovery? Do you have any examples of websites, companies, etc.?

Dr. T: You can visit the Canadian Sports Massage Therapy Association website for comments that it increases the circulation and helps flush out lactic acid. I think that it is just a case of this "common sense" explanation becoming dogma and not enough critical attention paid to data supporting or refuting it. I will be speaking at the CSMTA annual general meeting and conference in October in Toronto to report our findings and hopefully officially clear up the misconception so that information regarding massage and its possible mechanisms for beneficial effects is updated.

PJ: Your study suggests that massage may actually reduce blood flow to the area being massaged. What is the mechanism behind this effect?

Dr. T: This is quite simple. I think that when people originally thought about the "common sense" effect of increasing circulation, they were thinking of a mechanical "pumping" effect of massage strokes, and some kind of stimulation of blood vessels. However, in order to do the "pumping" and "stimulating" you have to use compressive force. During compression of tissue, you actually squeeze shut the tiny blood vessels in the tissue through which the blood is flowing. You can imagine that if you add this to the normal resting condition, you are adding intermittent impairment to flow. If there is an enhancement effect of massage it would occur between massage strokes. The net effect (increase or decrease or no difference) on blood flow depends on whether the magnitude of impairment or enhancement effects dominates.

PJ: Would the reduced blood flow be expected to aid or hinder recovery from exercise? Why?

Dr. T: A reduction in blood flow per se will reduce the rate at which phosphocreatine stores are replenished. However, this all becomes a moot point by 10 minutes following exercise as the degree of flow reduction with massage that we measured only occurred during the first 4.5 minutes post exercise. There may be other beneficial effects not related to flow, such that I would hesitate to say it is detrimental to recovery.

PJ: Icing and cold baths are other treatments which limit blood flow and are thought to promote recovery by limiting tissue inflammation. Could the reduction in blood flow following massage be beneficial in some circumstances?

Dr. T: I would suggest that in the conditions we studied, the "reduced" flow was still a very high flow, as the blood vessels in the muscle after strenuous exercise remain very open and do so for many minutes. So, in icing we are talking about a much different scale of flow. However, it is a good question and one to which, while there is no apparent reason to suspect a beneficial effect, there may yet be some merit.

PJ: As with many popularized misconceptions, there is often a grain of truth to the matter. Was there ever any actual scientific reason to think that massage would increase blood flow, and thereby aid in recovery or was it purely just an urban legend.

Dr. T: Sure. First, there was an early study that reported substantial measured increases in flow in the early 1950's. Second, there are two mechanisms that increase blood flow in a muscle when it exercises that could be triggered by the compressive strokes of massage. They are the muscle pump, in which emptying of the veins by mechanical compression results in an increased pressure gradient from arteries to veins when you remove compression, thereby increasing flow. Second, resistance vessels in muscle tissue dilate in response to compression. Both of these effects have considerable scientific evidence to support them. The reality is however that these enhancement effects can only manifest themselves during the removal of compression, and the compression itself actually shuts of blood flow, so the net effect depends on which of enhancement or impairment dominates.

PJ: Instead of massage, what would you recommend to aid in recovering from the latest exercise bout?

Dr. T: I don't think I would recommend not to get a massage. We have to remember two things: first, our study did not assess recovery performance, so we are not commenting on whether massage is detrimental to recovery. Further to that, no studies that do assess recovery have found a detrimental effect of massage (some find no effect and others find a positive effect on things like force recovery and inflammation recovery). Second, there may be other benefits of massage (it makes you feel better, and in the world of performance that counts for a psychological effect I would imagine).

PJ: And lastly, we have found that there is something so cathartic about setting the record straight on the nonsense that is out there. Are you planning on investigating any other possible myths in the near future?

Dr. T: Hmmmmm, I've always been skeptical about the existence of Sasquatch....

Although Dr. Tshakovsky’s research has been getting quite the media attention, and is thus surely ruffling a few feathers – particularly among massage therapists, there have been some studies in the past with very similar conclusions.

For example, a literature review by Wilfrid Laurier University’s Dr. Peter Tiidus published back in 1997 in the Journal of Orthopaedic and Sports Physical Therapy, stated the following:

“There is currently little scientific evidence that manual massage has any significant impact on the short- or long-term recovery of muscle function following exercise or on the physiological factors associated with the recovery process. In addition, delayed onset muscle soreness may not be affected by massage.”

Instead, in that paper, Tiidus recommends light exercise as the best method of recovering from strenuous exercise by elevating muscle blood flow and potentially reducing delayed onset muscle soreness (DOMS).

Apparently, some myths are tough to debunk…

Peter

Tiidus PM. (1997). Manual massage and recovery of muscle function following exercise: a literature review. Journal of Orthopaedic and Sports Physical Therapy, 107-112

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Can-Fit-Pro Says Eating More Beans May Improve Your Mood and Hair

Friday, July 17, 2009 Author: Travis Saunders 5 Responses
 Image by Natalie Maynor.

A few weeks ago I wrote a post comparing the Canadian Society for Exercise Physiology Certified Personal Trainer (CPT) and Certified Exercise Physiologist (CEP) designations with the Can-Fit-Pro Personal Trainer Specialist.  The crux of my argument was this - the Canadian Society for Exercise Physiology designations certify that your personal trainer has post-secondary education in Sport Science, specific core competencies, and a designated scope of practice, while the Can-Fit-Pro certification can be had by anyone who passes a 2-day course. 

Can-Fit-Pro has a monthly newsletter, to which I recently subscribed.  The Can-Fit-Pro certification is still quite common (I even briefly considered it myself), so I thought it would be interesting to read the information that they are sharing with their members.  I received their latest newsletter last week which contained two articles, both of which left me speechless.

The first article was titled Grab a Healthy Bite (I summarize below, but do yourself a favour and click the link to get the full effect).  It begins thusly:

Do you have weight loss goals? Are you achieving them? Do you find yourself cruising down the grocery store aisles, wondering what you should place in your cart and what you should leave out? Here are some of the most ideal must-haves every shopping cart should have!

The rest of the article consists of nothing but a list of foods.  I'm not kidding.  Here is a brief taste:

Top five carbs and whole grains
Oatmeal
Sweet potatoes
Beans
Multi grain cereal
Brown rice

The "article" also includes the top 5 veggies, fruits and proteins, before concluding with the following statement (followed by a pitch for their upcoming convention):

Shop wisely and eat healthy to achieve and sustain a balanced diet. You’ll notice improvements in your skin, teeth, hair, mood, and overall well-being.

Are they actually saying that if I eat more beans and other "top foods" (in apparently any amount, and independent of other lifestyle factors), I will notice improvements in my mood, skin, teeth, hair, and overall well-being?  Because that's what it sounds like to me.  What type of bean?  String beans?  Fava beans? Funky purple beans? And how does weight loss, which is featured prominently in their introduction, fit into the equation? The entire article consisted of nothing but a list of 20 random foods, with no information on why they are the "top 5" in their category, no information on how much to consume of each, no information on who this information applies to (athletes? obese individuals? healthy vs diseased populations?) or links to any further information to try to piece together what they are trying to say.  A less useful list would be difficult to imagine.  And this is from the group that "certifies" most of the personal trainers in mainstream Canadian fitness clubs.

While the first article was mildly amusing, the second (Bootcamp Your Butt into Shape) was more frustrating than anything else.  In it, author Bev Isla discusses the benefits of fitness "Bootcamps", and interviews bootcamp expert Deanie Blaine.  Bootcamps involve strenuous exercises which are typically performed outdoors (you often see these taking place in parks during the summer), and in general I have no problem with them.  But Ms Blaine makes some rather lofty claims that I'm not sure bootcamps can live up to:

According to Deanie, “[if you attend bootcamps] two times a week you are going to see a little bit of a change in your body whether it’s weight loss or more strength.

Exercise is critical for long-term weight loss.  But two sessions a week are not going to do it.  Especially when those sessions involve strenuous strength exercises, which may build muscle just as much as they burn fat.  But here is what really frustrates me - exercise is amazingly good for the body whether or not you lose weight.  And by telling people they might lose weight when they almost certainly won't (unless they make other long-term lifestyle changes), many will get discouraged and even quit because they have failed to reach their weight loss goal despite the fact that they were experiencing tremendous health benefits.  Overselling the benefits of minimal exercise with respect to weight loss is a bait-and-switch that leaves many people disillusioned with physical activity, and that has certainly contributed to the extremely low levels of physical activity in our society.  It's an easy trap to fall into, and we have probably even done it here (hopefully not since our early days).  Exercise is critical for long-term weight loss, but it needs to be consistent, performed several times a week, and in concert with other lifestyle changes - merely going to a bootcamp twice a week is not going to cut it.

Quite a newsletter, no?  It is frightening that some personal trainers may actually read this information, and pass it along to their clients.  There are enough obstacles for people trying to live healthy lifestyles as it is, uneducated (or mis-educated) personal trainers shouldn't be one of them.

Travis

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Top 10 ways to stay fit and healthy while traveling

Wednesday, July 15, 2009 Author: Peter Janiszewski, PhD 5 Responses
If Friday’s post was not enough of a testament of my dedication to this blog, then today’s post should convince most of our readers just how dedicated and utterly obsessed we are. At the moment, I am on board a U.S. Airways flight from Vegas to Toronto – the turbulence just after liftoff was a bit frightening – some people were screaming – apparently regular occurrence flying out of Vegas.

While my last post on staying active while traveling was mostly tongue-in-cheek, I thought it would be helpful for our readers to develop a top ten list for staying fit and healthy during your travels (in no particular order).

1. Do your best to maintain a proper diet – particularly during flight days when you could be on the go for over 12 hours and no regular meals. Preparation is key. Getting healthy food options on most flights and at airports is near impossible. Thus, bringing along some trail mix, dried fruit, granola bars and other healthy snacks will help with the hunger – not to mention prevent the inevitable GI distress you will likely experience by eating in-flight or airport meals. aSlo, once you arive at your destination take the time to scope out healthy eating options before opting for the hotel buffet.

2. Get plenty of sleep. Sleep deprivation can easily become a problem when traveling across time zones or during red-eye flights. While feeling tired can be a miserable way to start your trip, sleep deprivation can also result in you craving high-calorie, high-fat and high-sugar foods – not the best situation when already faced with limited healthy eating options. These cravings result largely from a change in your body’s hormonal milieu: levels of appetite suppressant, leptin decrease while levels of appetite stimulator, ghrelin increase in response to lack of sleep. I always travel with a set of good quality earplugs and something to cover my eyes – this way no matter my new sleeping quarters, I can more or less guarantee silence and darkness.

3. Walk as much as possible. Walking is one of the best exercises out there which requires nothing else beyond comfortable footwear (relative concern – I find flip-flops rather comfortable) and a surface on which to walk. As I made pretty clear in my last post on being active in Vegas, certain destinations really make it difficult for you to get much physical activity. I have always found that exploring any travel destination on foot is by far the most enjoyable, because:
A) You can find things off the beaten path (scenic spots for photos at the Grand Canyon which required a few steps also resulted in no other tourists ruining my Kodak moments)
B) You stumble onto people and places you would have otherwise missed (such as the 2 UFC fighters I spotted while in Vegas – Dan Henderson and hall-of-famer, Royce Gracie)
C) You save money on gas, parking, buses, trains, etc.
D) And let’s not forget the myriad health benefits associated with accumulating the recommended 10 000 steps per day.

4. Did I mention walking? Almost all airports I have ever been at are loaded with escalators, moving sidewalks, terminal shuttles or trains, automatic doors, etc. Whenever possible, avoid these calorie-sparing traps, and take the stairs or walk beside the moving walkway (see if you can beat those folks using the automatic methods of transport – my favourite activity). If you are in a real hurry (been here many times while trying to catch a transfer flight) at least do yourself the service of walking up or down the escalators or moving sidewalks – they are meant to speed up transit after all. I find it utterly infuriating when people just stand on these devices blocking both sides (remember, the right side of an escalator or moving sidewalk is for standing [if you must], while the left side is for walking – or sprinting, depending how close your departure time is).

5. Work-out regularly during your travels. Here you have options depending on your budget.
A) If you can afford it, by far the easiest option is to use the gym located at your hotel.
B)On the other hand, if you are on the verge of being broke just by taking a holiday, it may not be feasible to spend the $20 plus per day to use the exercise facility at your hotel. In this case you have a few options:
a) Throw together a resistance/cardio routine yourself in the hotel room using your luggage (it has handles so can work like a dumbbell) or any hotel furniture, incorporating as many body weight exercise as possible (i.e. pushups, lunges, crunches, etc.). I have found bringing along a set of elastic resistance bands which you can purchase at any sporting store to be quite helpful in making the in-room workout a bit more interesting.
b) Bring along a copy of your favourite exercise DVD. The benefit here is that you will no longer have to get very creative with furniture – less thinking for you.
c) You can check the hotel’s yellow pages for local fitness centres and contact them to find out about their daily or weekly rates – these are often much more reasonable than those at your hotel.

6. While on a plane – do the mini-exercise as described in most in-flight magazines. These exercises include heel lifts, neck rotations, trunk rotation in your seat, etc. Also go to the washroom often – just keeping your balance while walking to the facility while the plane is in motion is quite the balance exercise! This frequent walking will also help eliminate the risk of developing deep vein thrombosis on long-haul flights - a particular risk for those who are over 45 years of age and are overweight or obese, according to a study in the Archives of Internal Medicine. In this study, Schwartz and colleagues examined the prevalence of deep vein thrombosis in a group of 964 adults taking flights of 8 hours or more.  They report that 2.8% of passengers suffered a deep vein thrombosis during the flight, which could lead to pulmonary embolism or even death (which could obviously put a real cramp in the rest of your vacation!).  When first getting settled in, you can also help people stow their luggage in the overhead compartments – your shoulders will get a nice workout.

7. Unfortunately, some of the items listed in number 6 become a bit tricky if you have a window seat, so it is best to get an aisle seat. For example, it will be rather difficult to go to the washroom frequently, if the two passengers next to you have fallen asleep. Most airlines allow you to change your seat for free when you check-in, so snag an aisle seat to remove a major obstacle to staying active in the air. This was Travis' idea, as I tend to be a sucker for a window seat no matter how many times I have seen the CN tower when landing in Toronto...

8. Drink plenty of water – air tends to be very dry on planes so you tend to dehydrate easily, and that is a horrible way to start your trip. Drinking plenty of water also has some very useful side-bonuses.
a) Bonus 1. It is very easy to misinterpret thirst for hunger, meaning that if you’re dehydrated, you may be more likely to splurge on a bag of chips in the airport. By staying well-hydrated, you are less likely to over-eat, and you’ll feel better because of it.
b) Bonus 2. As noted in our last top 10 list, drinking plenty of water ensures that you will need a bathroom break about once an hour. This is perfect, because it gives you an excuse/urgent need to get out of your seat and stretch your legs – both activities that will help you feel your best when you hit the ground.

9. Pack wisely – always have a pair of sneakers and at least one set of workout clothes – this will eliminate the easy excuse for not being active due to lack of gear. If you have forgotten your work-out gear, you could either find a nearby mall and get some discount workout gear to hold you over, or alternatively exercise in your hotel room in the nude. This latter option is only appropriate when traveling alone or with a VERY understanding travel partner. Also, ensure the privacy tag is hanging on your door to avoid any awkward run-ins with the cleaning staff.

10. Really the most important piece of advice is to prepare everything before you leave. Make sure you look up the healthy food joints in the area, running trails, hotel services, gyms, etc. Planning ahead will ensure that you have done everything possible to obviate any potential obstacles you may encounter to staying fit and healthy.

Happy travels!

Peter

Schwarz T, Siegert G, Oettler W, Halbritter K, Beyer J, Frommhold R, Gehrisch S, Lenz F, Kuhlisch E, Schroeder HE, Schellong SM. (2003). Venous thrombosis after long-haul flights. Archives of Internal Medicine

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Power-pops - Lollipops that cause weight loss?

Monday, July 13, 2009 Author: Travis Saunders 3 Responses
 Image by FranUlloa.

"Can you imagine...

A lollipop with the amazing Power to Suppress the appetite and give you a burst of energy. What could be more simple?"


So begins a brochure promoting Power-Pops, a lollipop which claims to reduce appetite, increase energy, and help you lose weight.  Power-Pops have received a fair amount of media coverage in the USA, including the following video from the television program Extra (email readers can view the video on our main page by clicking here). 



I've got to admit, a lollipop that suppresses appetite is a pretty slick marketing idea.  Not surprisingly though, there is hardly any evidence to back up their claims of appetite suppression and weight loss, and some of their claims seem to defy basic physiological principles, or completely contradict each other. Let's look at them one at a time.

The primary "active" ingredients in Power-Pops are Hoodia, Citrimax, and Guarana - all popular ingredients in over-the-counter weight loss medications.  Hoodia, which I have discussed previously, comes from a plant found in South Africa which is said to suppress appetite.  While there is evidence that Hoodia can reduce appetite when injected directly into the brain, there is not a single clinical trial in humans to suggest that Hoodia has any effect on appetite or body weight, leading the Mayo Clinic to conclude that "There is no conclusive evidence that hoodia is an effective appetite suppressant or that it contributes to significant, long-term weight loss".


Let's move on to the second major ingredient in Power-Pops - Citrimax.  Citrimax is the fancy name for hydroxycitric acid (HCA), which comes from a plant called Garcinia cambogia.  Steven Heymsfield and colleagues at Columbia University performed a randomized controlled trial examining the effects of 12 weeks of HCA consumption in overweight men and women, which was published in the Journal of the American Medical Association.  Sixty-six subjects received a daily dosage of HCA, while 69 subjects received a placebo.  This study was double-blinded, meaning that neither the subjects nor their physicians knew if they were receiving the HCA or the placebo.  This type of study is the gold standard for determining the effectiveness of a new drug.  What did they find?

The HCA group lost weight... But no more than the subjects in the placebo group.  In fact, the placebo group actually lost slightly more weight than the HCA group, although this difference was not statistically significant.  Body weight isn't always an ideal measure, so what about body fat specifically?  Heymsfield and colleagues concluded that: "there were no observed selective fat-mobilizing effects specifically attributable to the active agent, hydroxycitric acid".

The take home message?  Citrimax (aka HCA, aka Garcinia Cambogia) is literally as useful for weight loss as a sugar pill.

And what about guarana, the third and final major ingredient in Power-Pops?  Guarana is a natural source of caffeine, so it actually has some potential as an appetite suppressant.  For example, Boozer and colleagues have reported that a combination of Guarana (caffeine) and Ma Huang (ephedrine) resulted in a significant decrease in body weight and body fat in overweight men and women.  However, one quarter of the subjects receiving the Guarana and Ma Huang dropped out due to severe side effects which included dry mouth, insomnia, and headaches.  Further, combining caffeine and ephedrine is very dangerous, so do not try that at home!

What I find very interesting is that although Power-Pops claim to contain guarana, their website also claims that  "These delicious lollipops do not contain... Caffeine or other types of ingredients that "speed" you up." [emphasis added].

Now they never say on the website how it is possible to have guarana as an ingredient while remaining caffeine free.  That would be like putting coffee grounds in a cake but claiming it has no caffeine - it doesn't make any sense.  And even if they used de-caffeinated guarana (if such a thing exists), caffeine is the reason that guarana is used as an appetite suppressant!  That would mean that they took out the only ingredient in their product which is thought to have any impact on appetite! 

So as far as the active ingredients in Power-Pops are concerned, there is very little evidence to suggest that they have any effect on appetite.  In addition, the Power-Pops brochure makes some claims which are so strange that they need to be pointed out.  For example, how can Power-Pops "give you a burst of energy" without having any "ingredients that "speed" you up"?  Further, they claim that you should drink a glass of water and eat one Power-Pop 30 minutes before a meal in order to "activate" the ingredients.  In fact, the brochure claims that "Water is the most important ingredient of the Power-Pops".  After the meal you are advised to drink another glass of water to "flush" the ingredients from your system.

This is probably obvious to our readers, but that is not how the human body works.  If the ingredients are activated by water, why wouldn't they be activated by the liquids that are already in your mouth and digestive tract?  Further, I have not come across any information suggesting that any of the ingredients in Power-Pops are "activated" by water.  What probably is happening, is that when you drink plenty of water (especially just before a meal), it can help reduce feelings of hunger.  So if you're drinking more water, you will be less hungry.  But it might not have anything to do with your lollipop.

The other claim made by the makers of Power-Pops is that it helps you burn fat.  This suggests that it somehow increases your metabolism, or helps you to specifically burn fat and spare carbohydrates.  I can't find any evidence to suggest that any of the ingredients in Power-Pops have any of those effects on the human body.  Caffeine can result in carbohydrate sparing, but as mentioned earlier, Power-Pops apparently contain no caffeine, so no dice there either.

I emailed the local Power-Pops sales representative to ask about the claims that are made in the Power-Pops brochure, and he was kind enough to put me in contact with Mike Wenninger, the creator of Power-Pops who is featured in the above video.  Mike called me almost immediately, and seemed very eager to chat about his product.  I was busy at the time so he said I could call him back in a day or so, but since then I have been unable to reach him by phone or email (I tried each several times).  It's unfortunate, because I was and remain very eager to discuss the claims that are made on various Power-Pops websites and brochures (especially regarding caffeine).  If there is any evidence behind any of the claims, then Mr Wenninger should have no problem pointing it out to me.  If I do hear from him again (if you're out there Mike, I'd still love to talk with you) I'll be sure to put it up in a future post.


In case you still want to try Power-Pops yourself, the Canadian website can be found here.  They claim to be delicious, and of this I have no doubt.  In Canada they are affiliated with the tanning salon iTAN, so if you frequent them be sure to ask if they know anything about the strange claims being made about the product.  One bag of Power-Pops contains 30 lollipops and costs $28.95,which would last all of 10 days if they are being consumed before every meal as suggested - weight loss tools with this much science behind them don't come cheap.


A big hat tip to my friend and co-worker Kelly Heffernan for bringing Power-Pops to my attention.  And to receive the latest obesity news and research by email, please enter your address in the "Subscribe via email" box in the upper right-hand corner of this post.

Travis

Related Posts:

1.  Hoodia for weight loss - where's the evidence?
2.  Acai berry scam - we called it!
3.  Leptothin - nature's most powerful weight loss agent?

Heymsfield, S. (1998). Garcinia cambogia (Hydroxycitric Acid) as a Potential Antiobesity Agent: A Randomized Controlled Trial JAMA: The Journal of the American Medical Association, 280 (18), 1596-1600 DOI: 10.1001/jama.280.18.1596

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Staying fit in the city of sin...and laziness

Friday, July 10, 2009 Author: Peter Janiszewski, PhD 2 Responses
Travis and I are often asked how we find the time to write blog posts on a regular basis. While we often shrug it off and say how it has just become part of our schedule, making regular blog posts on certain days requires some serious determination. Today (while on vacation) I am writing on location at Ceasar’s Palace on the strip in Las Vegas (I found some free WiFi to make this post possible). Although I brought with me a copy of a recent study that I was planning on discussing (yes, I am obsessed), after my first day of exploring the famous strip, I decided to discuss something different with the help of a photo diary.

Staying fit and eating healthy while on vacation or at a conference has become a recurring personal struggle. When at home I have a regular workout schedule, a gym membership, my regular running trails, biking paths, etc. I also have complete control of what I eat, when I eat, etc. When I leave my bubble in Kingston, it is always a challenge to maintain both my physical activity and dietary patterns.
Some destinations are a greater challenge than others.

Case in point: Las Vegas, Nevada in the peak of the summer.

The facts:

1. It has been over 40 degrees Celsius (the nightly lows have been around 28 degrees), with a relative humidity of 2 percent (the driest I have ever experienced) every day since arrival. To make things more interesting, there have also been some rather fierce hot winds which kick up dirt in your eyes and mouth and strip your body of moisture. Thus, performing any physical activity outside can only lead to dehydration and heat stroke.

2. While there is a gym at the hotel I am staying at, I can’t afford the daily $20 fee to use the facilities.

3. As will become obvious in the photos below – there are escalators EVERYWHERE in Vegas. In fact, it is often the only way to get from point A to point B – there are simply no stairs! Other times, even a flat walkway is mechanized (think airport walkways). Thus, even getting some decent steps in while exploring the city is made difficult.

The solution: being creative to stay active …. and by extension getting many confused looks from other tourists.

For example, when walked on backwards the escalators become great stepping machines while the flat walkways become gigantic treadmills.
When you can find stairs - take them - even if you are the only one doing so.

Hotel room furniture and luggage can be used to improvise a decent resistance training session.

Even when checking out popular tourist attractions such as the Hoover Dam you can always find a way to squeeze in a few reps of hanging leg raises to work on that six-pack (pictured below).

And don’t forget the casino – here’s an example of one of my favourite casino exercises – giant slot machine rows.
Lastly, we have been able to find a great grocery store nearby (Whole Foods) which allows us to eat the amount of fruit and veggies we are accustomed to (something which is rather difficult while dining exclusively at restaurants – especially when visiting places like Vegas, Phoenix, and New Orleans - from recent experience). This store has a great buffet style section with a bunch of relatively healthy options made to go – i.e. a great salad bar. For the past two nights, rather than blowing a bunch of money on predominantly deep-fried options, we have dined at the grocery store. For breakfast we have been eating plain yogurt with some granola as a substitute for our usual oatmeal. We also ensure to bring along some snacks when exploring – a couple bananas and a protein bar is my personal strategy. Having some snacks ready ensures than when hunger does strike I can: a) stave off the ‘hangries’ – the distasteful mood brought on by low blood sugar (I get cranky) and b) make a smart decision with regard to meal selection (when absolutely famished even McDonalds starts to look like a good dining option).

Next on the itinerary is a trip to the Grand Canyon - that should be interesting given the current climate...

Peter

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Influence of sex on regional fat loss in overweight men and women.

Wednesday, July 08, 2009 Author: Travis Saunders 2 Responses
 Photo by Sylvar.

Last week I discussed sex-differences and obesity related metabolic risk among elderly men and women. This week I'd like to stay on the topic of obesity related sex-differences, focusing on a paper by Drs Jen Kuk and Bob Ross (not that Bob Ross) which was published recently in the International Journal of Obesity.  In this new study, Drs Kuk and Ross examined the influence of sex on regional fat loss in overweight/obese men and women in response to diet and/or exercise interventions.

Interestingly, they report that for a given amount of weight loss, men lost more visceral fat (fat surrounding the internal organs in the abdomen), while women lost more lower body subcutaneous fat (the fat you can pinch on your legs, hips, and buttocks).  That may seem trivial, but it's important to note that visceral fat is closely associated with disease risk and even mortality, while lower body subcutaneous fat often has no relationship with health risk at all (while in some situations it is even protective).  Theoretically (and I stress that it is theoretical), this suggests that for a given amount of weight loss, men may actually experience more health benefits than women.

I found this study very interesting, so I thought this would be a great opportunity to do another Obesity Panacea interview.  Not only is Dr Kuk an excellent researcher, but she is also a close friend of both Peter and I.  She was a lab-mate, mentor, and roommate (briefly) at Queen's University, and has co-authored several papers with us (mostly with Peter, but my first formal collaboration with Jen was accepted for publication earlier this week, and will be featured on the blog in the very near future!).  She was kind enough to take the time out of her busy schedule as an Assistant Professor at York University to answer a few questions on the study, why she feels waist circumference is a better measure than the waist-to-hip ratio, and what she thinks is the most important message of her research to date.


TS:  You found that for a given amount of weight loss, men and women lost the same amount of body fat, but men lost more visceral fat, while women lost more lower body subcutaneous fat.  Why do you think that is?


JK:  In part, some of the sex differences are because of how much regional fat men and women begin with.  Men tend to have more visceral fat than women, whereas women have more subcutaneous fat, particularly in the hip and gluteal regions.  So it makes sense that you would able to lose more of a specific tissue that you have an overabundance of.  Other reasons could be due to differences in hormones or the way fat is mobilized in men and women.  So in other words, it could be a difference in genetic programming. 


TS:  Given that your previous work has suggested that visceral fat is an independent predictor of mortality, does this suggest that women may need to lose more weight to experience the same metabolic benefits as men?  Do you know if men and women experience similar metabolic improvements for a given amount of weight loss?


JK: That's a great question.  There is some work suggesting that men and women have the same cardiometabolic profile for a given level of visceral fat (see Lemieux et al. Diabetelogia 1994).  This means that if a man and woman have the same amount of visceral fat, then you would expect they would have similar levels of glucose, lipids and blood pressure.  If this pattern holds true with weight loss, then it would suggest that men may have a greater metabolic benefit from a given weight loss, but this has yet to be shown in a study.  That said, this study should not deter women from trying to lose weight, as weight loss will improve your health and qualtiy of life regardless of whether you are a man or woman.  So in the end it doesn't really matter who has the advantage.  


TS: Do these findings have clinical implications? 


JK: As I said above, it doesn't really matter in the end who has the advantage with weight loss, both men and women should lose weight.  So in a sense, no...this study has no clinical implications ;)
[Travis' Note: For more on the clinical implications of the study, please see this post by Dr Arya Sharma on his blog earlier this week]


TS: Given the associations between visceral fat and disease, is there any way that people can "target" visceral fat specifically in their weight loss program?


JK: Like all fat depots, there is no way to target a specific fat depot, but exercise has been shown to increase the amount of visceral fat loss expected for a given amount of weight loss as compared to dieting.  In fact, you can lose visceral fat with exercise without losing weight.


TS:  You also report that waist-to-hip ratio is not a good predictor of long-term changes in body composition.  Could you briefly explain why a measure like waist circumference is a more useful longitudinal marker of body fat distribution?


JK: Essentially, the waist-to-hip ratio is not good particularly in women because you are comparing two things that are changing.  With weight loss, people will loss inches (fat) both from their waist and hip/gluteal region.  And so if you are coming your waist to your hip, you are kind of aiming at a moving target.  In men it is not as bad, as they generally do not lose very much from their hip and gluteal region, so the waist-to-hip ratio is more of a function of changes in waist.  Since waist alone is a better predictor of changes in visceral fat, and it's simpler to measure, just use waist.


TS: If people could take one message from your research to date, what would it be?


JK: Watch your waistlines, and walk yourself to a healthier you.

----

Thanks Jen for taking the time to answer our questions!  

For more information on Dr Kuk and her research, please visit her York University page here

Travis

Related Posts:

1.  Public transit and physical activity - an Obesity Panacea interview.
2.  Sex differences in obesity related metabolic risk in elderly men and women.
3.  Is losing fat from your thighs bad for your health?


Kuk, J., & Ross, R. (2009). Influence of sex on total and regional fat loss in overweight and obese men and women International Journal of Obesity, 33 (6), 629-634 DOI: 10.1038/ijo.2009.48

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Obese but healthy: Is weight loss detrimental?

Monday, July 06, 2009 Author: Peter Janiszewski, PhD 9 Responses

Earlier this year I discussed the notion of metabolically healthy obese individuals - that is, individuals who are clinically obese (body mass index >30kg/m2) and yet who appear to have perfect metabolic health (normal blood glucose, blood lipids, blood pressure, and cytokine profile).

While countless epidemiological studies have shown that as you move from a normal weight (BMI = 18.5-24.9 kg/m2) towards overweight (BMI = 25-29.9kg/m2) and obesity (BMI ≥ 30kg/m2) the risk of many diseases increases exponentially, it is also true that approximately 25% of obese individuals ­are metabolically healthy despite their excess weight.

Knowing the above, the question then becomes: should every obese person be instructed to lose weight for health reasons?

According to a recent study by Karelis and colleagues from Quebec, otherwise healthy obese people who lose weight via dieting may actually WORSEN their metabolic profile.

In the study, a sample of obese women were divided into either metabolically healthy (20 women) or metabolically at-risk (24 women) based on their level of insulin sensitivity (a marker of diabetes risk - the more insulin sensitive, the better) as measured using the euglycemic-hyperinsulinemic clamp procedure. These women then underwent 6 months of a medically supervised dietary weight loss program consisting of approximately 500-800 kcal reduction in daily food intake.

After the intervention all women lost a significant amount of body weight (approximately 6-7%).

More interestingly, however, while the metabolically at-risk obese women showed a 26% increase in their level of insulin sensitivity, the insulin sensitivity of the metabolically healthy obese women actually deteriorated by 13%!

This finding is very unexpected, and as of yet has not been corroborated by another study. Nevertheless, it does raise the very intriguing possibility that weight-loss among otherwise healthy obese women is not only unnecessary but, in fact, counter-productive.

This finding falls in line with a recommendation paper by Drs. Arya Sharma and Robert Kushner published in the International Journal of Obesity earlier this year. In that paper the authors proposed a novel obesity classification system which not only assesses weight, but also health complications of excess weight. Germane to the above discussion, Sharma and Kushner recommend that among obese individuals who have “no apparent obesity-related risk-factors” the goal of patient management should be to simply avoid further weight gain, or maintain current weight, rather than to induce weight loss. (To read Dr. Sharma’s full discussion of the new classification system please visit his blog here.)

In essence, the idea that healthy obese individuals may not have much to benefit health-wise from weight loss is not that surprising – they are healthy to begin with! However, whether weight-loss may actually be ill-advised for healthy obese individuals needs to be investigated by future studies which look at health outcomes other than insulin sensitivity. For example, it remains unknown whether exercise-induced weight loss among healthy obese individuals could also result in metabolic detriment (doubtful). Also, we have currently no idea if the above finding also holds true among men.

More on this topic in the near future.

Peter

Karelis, A., Messier, V., Brochu, M., & Rabasa-Lhoret, R. (2008). Metabolically healthy but obese women: effect of an energy-restricted diet Diabetologia, 51 (9), 1752-1754 DOI: 10.1007/s00125-008-1038-4

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Sex-differences in obesity related metabolic risk in elderly men and women

Friday, July 03, 2009 Author: Travis Saunders 3 Responses

Believe it or not fat cells are some of the coolest cells in the human body.  When I first came to do my Master's at Queen's, I just assumed that fat cells were a bad thing, and the fewer you had the better.  Sure, you needed a minimum amount of fat to protect your organs and avoid reproductive problems, but otherwise I didn't think that fat cells were all that important.  Fat cells are just a passive depot that stores excess calories, right?  Wrong.

One of the very coolest things about fat tissue is that it is an active endocrine gland, secreting hormones which have effects throughout the body.  These include inflammatory hormones like IL-6 and TNF-alpha, which can directly increase the risk of heart disease and diabetes, but also include the anti-inflammatory hormone adiponectin, which increases insulin sensitivity and reduces liver fat.  In a perfect world you would have lots of adiponectin, and not very much IL-6 or TNF-alpha.

When fat cells are small and healthy, they tend to secrete mostly adiponectin, which helps reduce inflammation, and keeps the body sensitive to insulin.  Not surprisingly, high adiponectin levels are associated with reduced risk of contracting diabetes or heart disease.  However, when fat cells grow too large they begin to secrete large amounts of the inflammatory hormones, and decrease their secretion of adiponectin, and these changes are thought to be a key mechanism linking excess body fat with metabolic risk (visceral fat, the "bad" fat stored around the mid-section, is thought to secrete especially high amounts of inflammatory hormones).  This is one of the reasons why obesity is such a heterogenous condition - if you have lots of body fat, but it is stored in a large number of small fat cells, you are likely to be quite healthy.  In contrast, if you have even a small amount of body fat, but it is stored in a small number of ballooning fat cells, you are likely to have very poor metabolic health (this is what is seen in individuals with lipodystrophy resulting from HIV treatment).


All of this brings me to a new paper published ahead of print this week in the Journals of Gerontology (Series A) which was authored by myself (my first as a lead author!), Peter, Dr Lance Davidson, Dr Jean-Pierre Despres, Dr Bob Hudson, and my Master's supervisor Dr Bob Ross.  We examined the links between body fat distribution and adiponectin levels in abdominally obese, elderly men and women.  What we found surprised us - although adiponectin levels were strongly and negatively associated with visceral fat levels in elderly women (which was expected), there was no association between adiponectin levels and visceral fat in elderly men (very unexpected).  Further, while adiponectin was strongly associated with other markers of metabolic health like insulin sensitivity and triglyceride levels in women, there were no such associations in the men.

For some reason, all of the normal associations between adiponectin and other factors were present in the elderly women in our sample, but not in the elderly men.There are a few reasons why this could be happening. Adiponectin is thought to be cleared by the kidneys, and some papers report that kidney function drops off more in elderly men than it does in elderly women.  In line with this theory, adiponectin levels were associated with age in men, but not women in our sample.  Thus adiponectin might just build up in older men, obscuring the true relationship between adiponectin and markers of metabolic health or body fat distribution.  As of right now though, that is mainly speculation.  This is important though, because there is some evidence that in elderly men, adiponectin may actually increase, rather than decrease the risk of mortality.  No one knows why this is the case, but it's clear that something very strange happens to adiponectin levels in elderly men, and I hope that this study helps us figure out why that is.

Now the title of the paper ("Associations of the limb fat to trunk fat ratio with markers of cardiometabolic risk in elderly men and women") may not seem related to adiponectin, and that is because the main impetus for the paper was to clarify some statistical issues which were raised by a study from another group.  I find the adiponectin data very interesting though, so I thought I'd focus on that here instead (if anyone out there has an unbridled desire to discuss the marginality principle or other statistical issues, I would be more than happy to oblige).  To read the paper in full, cite it, or nominate it for some sort of cool award for first-time lead authors, please visit the Journals of Gerontology website.

Have a great weekend,

Travis

Saunders, T., Davidson, L., Janiszewski, P., Despres, J., Hudson, R., & Ross, R. (2009). Associations of the Limb Fat to Trunk Fat Ratio With Markers of Cardiometabolic Risk in Elderly Men and Women The Journals of Gerontology Series A: Biological Sciences and Medical Sciences DOI: 10.1093/gerona/glp079

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We are PhD students in the School of Kinesiology and Health Studies at Queen's University in Kingston, Ontario. Our research focuses on the relationships between obesity, physical activity, and health risk. This blog is our attempt to consider the many "cures" for obesity that we read about on a daily basis. Enjoy.

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The opinions expressed here belong only to Peter and Travis and do not reflect the views of any organization. Any medical discussion on this page is intended to be of a general nature only. This page is not designed to give specific medical advice. If you have a medical problem you should consult your own physician for advice specific to your own situation.

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