2021's Dumbest Scientifically Published Exercise Recommendation For The Treatment Of Obesity

[First written blog post since March 2020. What an awful 20 months. Though the pandemic is certainly not over yet, it feels like it's time to start writing again. Not sure what the frequency of posts will be, but it's nice to be back]

I wouldn't have believed it was real if I hadn't seen this phenomenon so many times before - a research study trying to tie their findings to the treatment of obesity despite the findings being either incapable of leading to clinically meaningful weight loss, or ridiculous to suggest in the first place. Here we've got both.

Published in Cell Reports Medicine, the paper Altered brown fat thermoregulation and enhanced cold-induced thermogenesis in young, healthy, winter-swimming men looked at the brown fat stores of Scandinavian men who alternate brief outdoor winter swims with a dash to the sauna 2-3x weekly. 

What'd they find?

The non-randomly selected winter swimmers, all 8 of them, whose average BMIs were 23.7 and whose average age was 25, were found, when exposed to cold, to generate more heat from their brown adipose tissue than their 8 age and weight matched controls. 

How many calories did that brown adipose tissue heat generation burn? If we take their results at face value (their results are orders of magnitude higher than found in a prior study of albeit older subjects), they report that during a "cooling period" of 30 minutes (there was no difference during a "comfort state"), resting energy expenditure was higher in the winter swimmers by an extrapolated 484kcal/24hours. They also reported that winter swimmers spent on average 11 weekly minutes in cold water. So during those 11 minutes the winter swimmers might well be burning 3.7 more calories than their non-winter swimming counterparts - the equivalent number you'd consume eating 1/10th of a carrot. 

The paper is full of various hypotheses to try to tease out the findings from this very small study. 

But what struck me was their final conclusion, 

"Finally, our findings motivate investigations of winter swimming as a lifestyle intervention for increased energy expenditure in obese subjects as a potential weight loss strategy."

Really? Your n=8, non-randomized, observational study of young men without obesity, that didn't control for any weight related variables, which showed that during their 11 minutes of winter-swimming the swimmers might burn 3.7 more calories per week for 4 months than non swimmers motivates investigations of winter swimming as a potential weight loss strategy in people with obesity?

Photo By Jaan Künnap - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=87539864

Study Published Stating The Daily Mile Doesn't Improve Childhood Obesity Speaks To Risks Of Tying Weight To Exercise

Published this week in the International Journal of Obesity is Effectiveness and cost-effectiveness of The Daily Mile on childhood weight outcomes and wellbeing: a cluster randomised controlled trial whereby researchers reported on the impact a school year worth of 15 minutes of daily running had on children's BMIs.

It's an odd study in that we're talking about 15 minutes of running per day which literally no one should expect to have a marked effect on childhood obesity given both math (15 mins of children running, jogging, or walking a mile probably doesn't even burn the calories of a single Oreo) and the fact that multiple meta-analyses have shown that even far more involved school based PE initiatives don't have an impact on childhood obesity.

It's also odd because The Daily Mile itself doesn't tie itself to weight,

"The aim of The Daily Mile is to improve the physical, social, emotional and mental health and wellbeing of our children – regardless of age, ability or personal circumstances"

And it's a problematic study in that consequent to the wholly predictable non-exciting outcome, it's the sort of study that might be used as a means to discourage the program's continuation.

What might have been studied instead? How about the impact of the Daily Mile on marks, concentration, endurance, or physical literacy (note, they attempted to do some of this, but data collection was too poor for them to make many conclusions), or if there was a strong desire to tie it to something medical, how about blood pressure, heart rate recovery, mood, sleep, or lipid levels?

As I've said many times, dumbing down exercise to weight management shortchanges both the benefits of exercise and the realities of weight management, and frankly doing that in the name of a program that sees kids running an extra 15 minutes a day, and then seeing that published in a credible journal, speaks to just how pervasive and dangerous that practice is.

Most Generous Conclusion Of Chocolate Milk In Exercise Systematic Review And Meta-Analysis? It Will Increase Your Time To Exhaustion By 47 Seconds Over Placebo

Literally every time I write about chocolate milk being a beverage worth actively minimizing in your diet (have the smallest amount of it you need to like your life), someone inevitably chimes in to tell me I'm wrong because it's great for exercise recovery.

And I'm not sure how I missed this when it came out, but last year, the European Journal of Clinical Nutrition, published a systematic review and meta-analysis of randomized controlled trials involving chocolate milk and exercise recovery.

After excluding studies that didn't meet their inclusion criteria, the (non-conflicted) authors were left with 12 studies, 2 deemed of high quality, 9 of fair quality, and 1 of low quality with 11 having extractable data on at least one performance/recovery marker including ratings of perceived exertion, time to exhaustion, heart rate, serum lactate, and serum creatine kinase.

Their overall conclusion?

The systematic review and meta-analysis revealed that chocolate milk consumption had no effect on any of those variables when compared to placebo or other sport drinks.

Their most generous conclusion?

If they excluded one study from their analysis of the effect of chocolate milk on time to exhaustion then chocolate milk was found to increase time to exhaustion by 47 seconds over a placebo beverage. They also found, in another subgroup analysis, that lactate was slightly attenuated in chocolate milk drinkers compared to placebo (a finding that was not present in the high quality RCT looking at same).

(for a brief discussion on the stats involved and the subgroup analysis, here's a post on same from epidemiologist @GidMK who concluded that chocolate milk is "not a fitness drink").

Happy to have this post published so that I can share the next time someone inevitably tries to suggest that chocolate milk is magic.

Scotland's "National Walking Strategy" Actually Increased Recreational Walking (A Tiny Bit) For The Whole Population!

Cynically, I've been known to ask for examples of population based initiatives that actually led to sustained increases in physical activity (with the expectation of there not being any).

Well, I can't do so anymore as Scotland's managed to increase recreational walking by 13% over a 6 year period for the whole of their population!

Their National Walking Strategy targeted Scotland's 5 million residents with messages about the health benefits of walking.

The strategy involved multiple sectors including:

• Communication and public education.
• Transport and the environment.
• Urban design and infrastructure.
• Health and social care.
• Education.
• Community-wide approaches.
• Sport and recreation.

And together their aim was to create a culture of walking by way of developing better walking environments that supported ease and convenience.

How to counsel patients on physical activity became a topic in medical schools. The Daily Mile encouraged 1,000 schools to help every student walk, run, or jog a mile a day, increased funding for active transport programs was obtained including a doubling of infrastructure funding for same, #SoMe was leveraged to share encouragement and information to the public, and community walking programs were launched nationwide.

Now before you get too excited, the bar was low to begin with whereby the increase in walking represented the self-report of walking at least 30 minutes for recreation once over the past month, but at least it's a start.

Changing behaviour requires more than just education and a good reason to do so, it also requires a change to social norms and culture, as well as environmental engineering. Clearly there's more to do in Scotland and elsewhere, but nice to see that these needles might actually be movable.

Photo by Kim Traynor [CC BY-SA 3.0], via Wikimedia Commons

Move More, Eat More? New Study Suggests People Do Eat More When They're More Active, But Not Much

One of the possible reasons that in freely living humans exercise doesn't seem to add up to weight loss as math might predict is that freely living humans might eat back their burned calories. Some may do so consequent to increased hunger. Others to a sense of virtue and the inclination to reward themselves for their hard work. Others still because marketing has convinced them that they must refuel, recover, replenish, etc..

A new study,Activity energy expenditure is an independent predictor of energy intake in humans, published this year in the International Journal of Obesity, set out to look at this phenomenon.

Now to be clear, the study certainly wasn't designed to explain exercise's impact on weight. It was just 7 days long and it involved the retrospective analysis of data from 5 prior studies and did not directly measure energy expenditure or energy intake. Instead researchers utilized estimated energy expenditure by way of heart rate and indirect calorimetry data, and energy intake by way of known to be problematic food diaries.

My stats skills are nowhere near good enough to comment on the various treatments of the data, but here's the scatter plot of the impact of energy expenditure on energy intake.

The increase in energy intake the authors attributed to energy expenditure wasn't high, roughly 3% of total daily calories (around 70 in this sample), an amount too small to explain away exercise's often uninspiring impact on weight loss.

Truth be told, I'd have predicted the difference to be larger as eating more consequent to exercise is something I know many people do for one or more of the various reasons mentioned above.

Of course none of this changes the fact that exercise has tremendous health benefits at any weight and that weight shouldn't be your driver for upping yours if you're able.

Coca-Cola Funded ISCOLE Trial Continues To Conclude Lack Of Exercise Drives Childhood Obesity

When it comes to associations, causality matters - the importance of which is easily understood when considering childhood obesity and inactivity. Whether inactivity leads to kids to gain weight, or whether weight leads kids to become inactive have very different implications

My publicly expressed bias is that childhood obesity drives inactivity, and there's data to support that assertion including this study whereby when observed over time in 8-11 year olds, weight gain predicted inactivity, while inactivity did not predict weight gain, leading the authors of that study to conclude,

"adiposity is a better predictor of PA and sedentary behavior changes than the other way around."

As to what's going on, if I were to venture a guess, it'd be some combination of obesity related abject bullying (multiple studies demonstrate bullying is associated with decreased physical activity and obesity has been shown to be the number one target of schoolyard bullying, not to mention the fact that bullies may make fun of heavier kids when exercising explicitly), being one of the worst/slowest on a team, and increased effort involved, that lead heavier kids to decreased MVPA (moderate-to-vigorous physical activity).

Now I've blogged before about the Coca-Cola funded ISCOLE trial almost entirely ignoring the possibility that childhood obesity drives inactivity rather than the other way around, and recently, another study came out of the ISCOLE group that did the same.

(and if you're interested, here's a published discussion of the emails between ISCOLE investigators and Coca-Cola that not surprisingly suggests that these relationships have the very real potential to influence the framing of results even if funders not involved in study design)

The study, Joint associations between weekday and weekend physical activity or sedentary time and childhood obesity, published in the International Journal of Obesity, looked at weekday and weekend levels of MVPA and sedentary time in 9-11 year old children in 12 countries and their associations with obesity.

Yes, they were found to be associated.

Though they do have a single throwaway line speaking to causality,

"It is not known whether lower levels of physical activity are the cause or the consequence of obesity",

that did not stop them from writing this as their final line and conclusion,

"Since children have more discretionary time during weekend days than weekdays, children should be encouraged to increase physical activity during weekend days, especially a high level of MVPA"

which while true on the basis of health as a whole, when framed in the explicit context of childhood obesity as it is in this paper, seems to deny the much more likely case that weight simply slows kids down.

And honestly, that matters.

It matters because one of the most predominant stereotypical narratives of obesity is that it is a disease of laziness, and ISCOLE's recurrently utilized framing supports that stigmatizing message. It also matters because, if considered at least by the parents I regularly see in my office, inactive children with obesity are being regularly judged (and sometimes even shamed or bullied) by their well-intentioned parents for not being active enough to lead them to lighter weights and I can't help but wonder if this would still be the case if the meat of the discussions in these sorts of papers focused on the barriers to physical activity erected by childhood obesity itself?

I would love to see more research done on the various mechanisms by which childhood obesity might contributes to inactivity, and more longitudinal studies designed to test causality, rather than paper after paper with conclusions that to my confirmation bias at least, ignore the many reasons why kids with obesity are understandably less likely to be physically active, and in so doing, fail those poor kids.

If You Tie Exercise To Weight Loss It Can Lead To Statements And Recommendations Like These

I've long called for a rebranding of exercise to promote it on the basis of all of its incredible benefits, and explicitly not in the name of weight loss.

While on paper there's no doubt that people can lose weight through exercise (and in research studies too), in practice they generally don't. And though there's also definitely the suggestion that exercise helps to keep weight off (or serves as a marker or inspiration for maintaining a whole slew of weight responsive behaviour changes), when it comes to public health, I believe focusing on weight loss as the outcome of choice in exercise interventions risks those interventions' dissolution when weight loss doesn't occur.

Helping to make my point is a recent study published in the American Journal of Preventative Medicine. The study, Implementing School-Based Policies to Prevent Obesity: Cluster Randomized Trial, looked at the impact school based nutrition and physical activity policies had on weight.

The study found that while school based nutrition policies seemed to have an impact on weight over time, school based physical activity policies didn't.

Not measured of course, or at least not mentioned, were the impacts those physical activity policies might have had on other health related parameters (blood pressure, blood sugar, non-alcoholic fatty liver disease, mood, sleep, attention, learning, physical literacy, and more) - things that I think the literature would support as being far more likely to see exercise-related improvements.

But it's the study's abstract's conclusion that got me, as I think it does a great job of highlighting the risk of clinging to exercise as an important driver of weight loss. Here it is in its entirety (highlighting mine),

"This cluster randomized trial demonstrated effectiveness of providing support for implementation of school-based nutrition policies, but not physical activity policies, to limit BMI increases among middle school students. Results can guide future school interventions."

Suffice to say I think it'd be an incredible shame if results like these guide any future school related physical activity interventions, as the benefits of exercise are myriad, something these results wholly ignore, and if these results guide anything, they'd guide the avoidance or elimination of school based physical activity policies which would let kids down on so many levels.

Guest Post: The Problems With Balancing Accuracy And Reach In Science Communication: What To Do When Even Journals Want To Contribute To Media Hype (HIIT Edition)

Last week saw the publication of a new study in the BJSM entitled (highlighting mine), "Is interval training the magic bullet for fat loss? A systematic review and meta-analysis comparing moderate-intensity continuous training with high-intensity interval training (HIIT)". Understandably intrigued given a prominent medical journal was suggesting there was a magic bullet for fat loss, I clicked through, and then reading the piece I learned that the amount of fat lost that the BJSM was calling a "magic bullet" was a 1 pound difference, one which the study's abstract's conclusion described as, "a 28.5% greater reductions in total absolute fat mass (kg)". Duly surprised, I then took to Twitter to poke around and found that one of the study's authors, James Steele, was tweeting out a corrective thread to his own study's hype - hype which understandably and predictably led to an onslaught of media overreach. Intrigued, I approached him directly to ask about the discordance in tone between his tweets and his study's title and conclusion, and he sent me such a thorough and thoughtful response (explaining how it was the BJSM's editor who'd changed both), that I asked him if he'd mind my sharing his thoughts here as a guest post. Suffice to say, in my opinion, medical journals and their editors shouldn't be in the business of clickbait hype, as it diminishes themselves, research, and furthers societal scientific illiteracy by suggesting that such things as "magic bullets" for weight or fat loss can conceivably exist.

I was first slightly concerned that the findings would be overhyped and potentially misrepresented when I saw the press release that was sent to the media. I was forwarded various requests by our institutions news team and saw the wording of the first line of which was

“Short bursts of high intensity exercise are better for weight loss than longer sessions in the gym, research suggests.”

My colleague James Fisher noted to me that he also thought the press release didn’t reflect the findings accurately and wondered whether the title change resulted in the perception of a different finding.

The original title in our submission to the journal was

"Comparing the effects of interval training versus moderate-intensity continuous training on body adiposity: is it possible to find a signal in the noise? A systematic review and meta-analysis"

which was chosen as an homage to Nate Silvers' book and the use of meta-analysis to find the ‘signal’ from among the ‘noise’ of conflicting findings in smaller studies The paper underwent peer review as normal and we made changes suggested by the reviewers to improve the manuscript; but, none of the reviewers commented on the title if I recall. After the reviewers were happy with the paper and had no further changes they wanted we received a recommendation that it be published, but with minor revisions which were suggested by the editor. Most of the revisions suggested where helpful as they seemed to be aimed at improving readability of the manuscript. However, it was also suggested that the title was changed, as well as the addition of the percentage difference to the conclusion of the abstract. This was suggested to be intended to attract more attention to the article, make it seem more compelling, and ensure recognition was received for the work. I didn’t particularly like the newly suggested title, nor did some of my co-authors, but it was not strictly saying that anything ‘was’ a ‘magic bullet’ and so I did not push the issue. I must confess I did not at the time notice the seemingly minor change to the abstract conclusion though. I personally dislike the presentation of % values in this manner as to me they are often misleading and detract from whether the absolute values are really meaningful or not (a big problem in sport and exercise IMO wherein a lot of studies make interventions seem better than they are by reporting % values). The value is not inaccurate, but it does lead the less wary reader to potentially draw the wrong conclusions.

I did suspect that the changes were suggested because the paper would likely be selected for a press release which turned out to be correct. I’m glad the paper got some wide coverage, but wanted to make sure it was covered in a nuanced manner. So I tweeted a little thread to try and provide some balance and when I was interviewed about it on BBC World Service I also made sure to provide as balanced a commentary as I could in the time permitted.

It doesn’t surprise me that the media initially interpreted things to be saying that ‘HIIT’ (high-intensity interval training) was better than ‘MOD’ (moderate-intensity continuous training) for fat loss without considering all the nuance… that’s just how it goes sadly. I also can empathize with the journal and publisher in wanting to try and increase the reach of the work that they publish. To my mind if we can widen the reach of good science, and raise appreciation of its importance, then that’s a good thing. This is something I’d like to be able to do more of. But, though this is good in principle, in execution it proves to be difficult. It’s tough to get the nuance across because science is hard and most people aren’t really able to understand it. I guess it’s part of the media cycle though. The wider media wants ‘stories’ and just regular boring old science doesn’t make for a good story. So to get the wider media’s attention journals and academic publishers need to try and make things seem more exciting. In that process though nuance gets lost. However, I can’t think of any other way to communicate science more widely at the moment. I guess what we need to ensure is that, once the media get hold of a story and want to run it, the actual scientists themselves are the ones they speak to and interview so they end up with a platform and captive audience to explain the nuance and implications in an understandable manner. At least, that’s what I’ve tried to do and hope I achieved.

I think if I was able to ‘do over’ this example specifically then I would have likely pushed back more on the issues. I would like to have kept the original title and would have argued for this position as I suspect my co-authors likely would have too. I definitely would have pushed back on the change to the abstract conclusion and will be more vigilant to these issues in future. In likelihood this might have meant the paper would have been less ‘impactful’ as a story for the media. But it would have meant that the paper itself didn’t contribute to any potentially misleading publicity. The publisher could have still put out the press release as they desired… Can’t stop them from doing that. But at least the paper would have better reflected what we found in full. I think I would advise authors who face similar situations to make sure they think and have a conversation about this. We all want our work to reach the widest audience to hopefully have the biggest impact possible. But we don’t in the process want it to distort in terms of its message. Make sure to discuss it with your co-authors and the journal/publisher and find the right balance so that scientific integrity is retained, whilst reach is maximized. It’s tough to do, but worth striving for IMO.

Dr James Steele is the Principal Investigator at the ukactive Research Institute, and Associate Professor of Sport and Exercise Science at Solent University. James completed his BSc (Hons) in Applied Sport Science in 2010, and hid PhD examining the role of lumbar extensor resistance training in chronic low back pain in 2014. He has extensive experience of research and applied consultancy in the area of physical activity, exercise, and sport from over the past decade, working with a wide range of populations ranging from elite athletes across a range of sports, to the general population across the lifespan, and both those who are healthy and diseased. James has published numerous peer-reviewed articles and delivered several invited talks at international conferences on a variety of areas relating to sport, strength and conditioning, physical activity and exercise, health and fitness. He was appointed to the Expert Working Group revising the Chief Medical Officers Physical Activity Guidelines for the UK and is a Founding Member of the Strength and Conditioning Society, as well as the Society for Transparency, Openness, and Replication in Kinesiology, and member of both the British Association of Sport and Exercise Sciences and the American College of Sports Medicine.

It Takes the Former Global Senior Director of the Gatorade Sports Science Institute Just 42s To Summarize Why You Almost Certainly Don't Need Sports Drinks

I caught this video a week or so ago.

It features one of the world's most prominent sports nutrition scientists, Asker Jeukendrup, answering the question,

"What is the shortest duration of exercise where eating or drinking is worthwhile?"

The answer?

It was refreshing to hear (see what I did there), especially given Dr. Jeukendrup's prior role as the Global Senior Director of the Gatorade Sports Science Institute (GSSI), that if your workout is less than 45 minutes (and by exercise he clarifies, "all out exercise, not easy running") you need nothing. And if it's 45 minutes to an hour and 15 minutes, a "mouth rinse" will do.

Wish that were printed in bold on the sides of Gatorade bottles, or that their bottles were mouth-rinse sized!



And of course this all reminded me of that time back in 2012 when I tried to create my own homemade version of Powerade after the then Senior Vice President of Coca-Cola's sparkling beverages division told the media that after her son's lacrosse practices, she took him to McDonald's for a 32oz of the stuff. Watching it I also had to wonder, "Did I even lift?" (not as much back then, no)

There's No Realistically Prescribable Amount Of Exercise That Will By Itself Lead To Useful Weight Loss, But That Doesn't Mean You Shouldn't Exercise!

This isn't the first time I've noted that there is no realistically prescribable amount of exercise that by itself will lead to clinically meaningful weight loss, and it probably won't be the last. And that said, it doesn't mean it's impossible, but reality really is a useful place to live, and is probably a worthwhile frame of reference.

Today's reiteration stems from a recent-ish study that looked at "energy compensation in response to aerobic exercise training in overweight adults" which when translated refers to whether or not people eat back the calories they burn exercising and if that's why the results of exercise for weight loss studies so often disappoint.

The authors followed 36 men and women with varying degrees of excess weight (BMIs ranged from 25-35) and randomly assigned them to exercise either 30 minutes daily or 60 minutes daily, 5 days a week, for 12 weeks.

3 months on analyzed data later and the authors summarized conclusions include this statement,

"Results of the current study suggest the recommendation should be closer to 300 minutes per week to achieve appreciable fat loss"

because in their study it was only the participants who averaged 335 minutes of weekly exercise who were seen to lose a statistically significant amount of weight (and though significant statistically, it was only an average of 5.7lbs).

Though it's not noted in the study, it should go without saying that whatever intervention you employ to lose weight, if you stop that intervention, the weight you lost by way of its impact will likely return. And so while perhaps 335 minutes of weekly exercise for another bunch of months would lead to further loss, if you stop or decrease exercising that much, the weight you lost with it is likely to return.

Back to the headline of this blog post. If you think the average person, living a real life, replete with its many stressors, challenges, and responsibilities, can sustainably and consistently find upwards of 300 minutes of weekly exercise, I'd invite you first to get that much yourself even for just 3 weeks, as for the majority of people out there, it's not even a remotely realistically prescribable amount.

Instead of continuing to tie exercise to weight, and in so doing motivate people to start exercising in the name of weight loss, which in turn risks disappointment and the cessation of exercise if while successfully increasing exercise to a more realistically obtainable amount no weight is lost, the focus needs to shift to the fact that exercise is arguably the single healthiest modifiable behaviour anyone can undertake, that any amount is terrific, and that it's incredibly beneficial regardless of whether or not weight is lost in the process.

Photo by David Whittaker from Pexels

ParticipACTION Report Cards Remind Us Every Year How Badly We're Failing Canadian Children

(Originally posted in 2016. Since nothing's changed, reupping it with 2018 data)

We suck at helping our kids to be active.

Here are the past 14 years of ParticipACTION kids' activity report card grades (click on 2018 for this year's edition):

2018: D+
2017: Didn't happen
2016: D-
2015: D-
2014: D-
2013: D-
2012: F
2011: F
2010: F
2009: F
2008: F
2007: F
2006: D
2005: D

So what has Canada done about it?

From my vantage point, it sure doesn't seem like much.

As to what we could we doing, I'm honestly not sure.

One thing I am sure of though, simply telling kids to be more active (or telling them and/or their parents how inactive they are) clearly isn't doing a whole heckuva lot. We need changes that change the default.

If you're a parent, I've blogged about the simple solution you could employ to help your kids move more (move with them).

If you're an educator, how about making every classroom/student reward an active one instead of relying on junk food (same goes for all of your various fundraising endeavours)? Oh, and get rid of inane over-protective schoolyard rules like bans on hard balls that effectively stifle active play.

If you're a city planner, how about more time and attention paid to developing safe, comprehensive, and unified biking and walking infrastructure?

And consider too the fact that decreasing kids' physical activity may well also be influenced by their rising weights (and not the other way around). I've worked with so many parents who report that as their kids gained weight, suddenly their interest in favourite activities waned. The why is something people either forget or overlook. Kids are cruel. Being picked last because you're slow, or simply not being able to keep up, would make most kids not want to play. One comment about "jiggling" while a kid runs is liable to lead a kid to stop running. Not wanting to change in front of your peers because of fat jokes and weight bias makes is another common hurdle. Here we need to see calls to action to tackle weight bias, and continued work towards improving the way we use food with our children, and ideally ending the regular use of foods by our kids' schools, teachers, coaches, cities, scout leaders, friends' parents, etc. to reward, pacify, and entertain them at every turn.

So how many more years of reading these depressing report cards before we either stop issuing them, or actually do something about the problem?

How Your New Year's Resolution To Up Your Exercise Might Lead You To Up Your Weight

As has been my tradition, in December I repost old favourites from years gone by. This year am looking back to 2014 and given it's New Year Resolution time, figured this might be worth revisiting.

File this study under reality.

Researchers were curious whether or not labelling exercise "fat-burning" (as many exercise machines do) would have an impact on how much food a person ate post exercising.

The protocol was simple. Subjects were brought individually to a lab and were told they were there to evaluate newly developed training software for bike ergometers. They were then equipped with a heart rate monitor and completed a 20 minute low-moderate intensity cycle. Participants were randomly assigned to have one of two posters tacked to the wall in front of them while they rode. The first had a poster stating, "Fat-burning exercise – developing training software for exercise in the fat-burning zone.", and the second, "Endurance exercise – developing training software for exercise in the endurance zone." Following their rides subjects were told they could help themselves to snacks while completing a survey and were offered water and pretzels. Pretzels consumed were measured by means of a scale before and after each participant.

The results?

"Fat-burning" labels did have some impact, but I'm not going to dwell on it. Instead I want to point out that across both treatments participants burned on average 96 calories during their rides and they then proceeded to eat 135 calories (41% more calories than they burned) of post-exercise pretzels.

Combine these results with those from a study published a few weeks ago that people who went for a walk and told they were "exercising" consumed 41% more calories from indulgent desserts and drinks following a post-walk lunch than those who were told they were walking for "fun".

We do eat because we exercise and I think in large part it's because we've been taught that we're supposed to - both by the food industry (see up above) and sadly too, by public health departments (see down below with the "Less Sit, More Whip" City of Ottawa bus poster) and health professionals who have markedly overplayed exercise's role in weight management.

If you are interested in weight loss, make sure that regardless of how much you're exercising, you're paying attention to to food as well.

Lose weight in the kitchen, gain health in the gym.

High School Phys-Ed Horror Story Highlights Risk of Tying Exercise To Weight Loss

As has been my tradition, in December I repost old favourites from years gone by. This year am looking back to 2014.

Thanks to Jonathan Clow for sharing this story with me.

So last year a PE teacher at Huron Park Secondary School in Woodstock, Ontario had their Grade 10 co-ed class use scales and measuring tapes in front of one another to calculate their body mass indices. Why? Because his gym class for the semester was to include once weekly circuit training that consisted of ten 90 second stations of burpees, weighted squats and other squat variations, mountain climbers, with no breaks, then a water break then 2 more circuits at 60 seconds and 30 seconds each without a break in between. At the end of the semester the kids were to once again publicly re-weigh and measure themselves in order to see how much weight their once weekly circuit training helped them to lose.

Oh, and he also allegedly informed the kids whose BMIs were elevated to begin with that they would likely develop diabetes.

No doubt the PE teacher was well-intentioned and felt that both public shame and just a bit of moving around would help his students because as far as he was concerned weight is an "energy balance" issue between in and out and that if he just had the kids up their "out", the problem would be solved. I've no doubt too, that his sentiments represent the societal norm rather than an exception.

I'm told the kids mounted a boycott and letter writing campaign to the school but am unsure on how it all shook out. Fingers crossed for the kids.

I'd imagine there are many more such PE based horror stories out there, and if the teacher or school is reading this, perhaps he might have a peek at this meta-analysis of school PE programs which demonstrated yet again (and yes I know I'm a broken record), that weight wise, kids aren't going to outrun their forks, or this study that suggests negative experiences in high school PE may well discourage the adoption of a commitment to lifelong exercise.

Bottom line for all of us - exercise should be cultivated and promoted on the basis of health and fun, and fat shaming has no place (or utility) in society let alone in a high school's curriculum.

Whether Or Not You Can Outrun A Bad Diet Depends On Your Finish Line

If you're trying to run away from weight, the likelihood of you succeeding without also addressing your diet is pretty darn low.

On the other hand, if you're trying to run towards health, well then my money's on your feet.

Exercise is, second only perhaps to not smoking, the most important health behaviour anyone can cultivate.

Whether you're running to reduce the risk or burden of most chronic diseases, or to preserve and improve your functional independence, or to reduce pain, live longer, improve sleep, bolster mood, gain strength, lengthen endurance etc., increasing and sustaining regular exercise, regardless of weight and independently of diet, is incredibly powerful.

And I'm not aware of there being any credible voices suggesting otherwise.

Of Course You Can Be Fit And Fat

Undeniably fit ultra-marathoner Mirna Valerio (from a 2015 Runner's World story (am quoted))

How about I pose a different question.

Can you be fit and have diabetes?

Of course you can. It'd be ridiculous to suggest otherwise.

So why doesn't the question of whether or not a person can be fit and fat sound equally ridiculous?

Why instead do we regularly see articles like this recent one from the New York Times that cover the "controversy" of the fit fat person?

In part it's because these stories conflate fitness with being free from other chronic diseases and/or from the risk of developing other chronic diseases.

But is that the average person's definition of fitness?

I don't think so.

I think most people think of fitness as the thing one gains as a consequence of regular exercise. That's why when it comes to the question of can you be fit and have diabetes, it sounds ridiculous as of course you can exercise and have diabetes.

Well guess what, you can also exercise and have obesity.

And in fact, that same study on which the New York Times based their article, didn't even try to quantify whether or not exercise provided health and/or quality of life benefits to people with obesity (of course exercise does). It simply looked at the heart disease risk of people with obesity, who didn't have other chronic medical conditions.

So basically the study concluded that obesity ups cardiovascular disease risk, not that those with obesity couldn't be fit.

And exercise mitigates, to varying degrees, the risks associated with virtually all chronic diseases, and obesity is no different.

Coming back to why we see stories in even the world's most reputable newspapers framing fitness and fatness as a controversy, well I think it just comes down to weight bias - specifically the trope that assumes that anyone with obesity must be lazy, because without that bias as a backdrop, there really isn't much of a story.

Early Childhood Physical Activity Does Not Vaccinate Against Obesity

By Pete (originally posted to Flickr as determination_0970) [CC BY-SA 2.0], via Wikimedia Commons

It's not uncommon when I meet parents of children with obesity for them to tell me either that it doesn't make sense because their child is extremely active, or that inactivity is to blame for their child's struggles.

And while my confirmation bias is that weight leads to inactivity in kids rather than inactivity to weight, data is somewhat mixed, with some studies finding total daily energy expenditure in very young children is associated with lesser weight gain, and others, not.

One of the shortcomings of prior studies were that they focused primarily on energy expenditure measured during a child's first year of life, and didn't cover the period known as adiposity rebound whereby BMI typically decreases until the age of 4-7 years before beginning to increase through late childhood.

A recent small study, High energy expenditure is not protective against increased adiposity in chldren, included that time period.

Briefly, 81 subjects who were classified as either at low risk of developing obesity (in that they had lean mothers with an average BMI of 19.5), or at high risk (mothers with an average BMI of 30.3), were recruited, and 53 remained through to the study's conclusion of 8 years. Three measures of adiposity at 8 years were collected - BMI percentile, BMI Z-score, and percent body fat. Total energy expenditure was measured using doubly labelled water at 4 months, 2, 4, 6, and 8 years of age (though only 58% of all total measurements were collected). Body composition was measured by way of bio-impedance analysis at ages 0.25 and 2 years, and by way of DEXA at ages 4 and 6.

What was found was that total daily energy expenditure increased with body size, but,

"there was no evidence supporting the hypothesis that a low habitual TEE for that body size leads to subsequent increase in BMI or % body fat"

Nor was there an association between measures of adiposity at age 8 and total energy expenditure between the ages of 0.25 and 6 years.

The authors overarching conclusion is that when it comes to the genesis of childhood obesity, it's energy in, not energy out.

I can't help but wonder, were that to be the prevailing belief, would parents with concerns about their children's weights be more conscious of their children's diets (especially liquid calories and purchased meals) as energy-in is something that many parents deemphasize during our initial discussions.

More Evidence That More Exercise Doesn't Up Total Daily Calorie Burn

Why is it that exercise doesn't seem to help appreciably with weight loss (and for those who enjoy building strawmen out there, note I'm talking about weight loss, not fat loss, nor fitness, nor health)?

One possible reason is that many people eat back their exercise in the form of a reward for doing it, or because they have been taught by savvy marketers that they need to refuel or recover something or other.

Another possible reason is that upping intentional exercise may lead bodies to decrease unintentional calorie burn (decreased fidgeting/NEAT, decreased autonomic tone, etc.) and also by way of improved exercise efficiency.

Overarchingly the latter theory is called constrained energy expenditure, and the evidence on all of this is early, and somewhat mixed.

Well a few months ago another block was added to the pile (at least for older women without obesity) suggesting constrained energy expenditure is a real phenomenon. It was a study published in Physiological Reports and it detailed the impact that a 4 month long moderate-intensity walking program had on the total daily energy expenditures of older women without obesity.

The study's 87 included participants reported being physically inactive, and weren't found to have any significant medical issues. The group was randomized into either receiving one of 2 doses of moderate intensity exercise for 4 months. Importantly, the exercise itself was supervised. Before and after measurements included resting energy expenditure (via indirect calorimeter), total daily energy expenditure (via doubly labeled water), body composition (via DEXA), graded exercise test (via treadmill VO2 max), physical energy expenditure (TDEE*0.9-RMR (to account for thermic effect of food reduced by 10%), and NEAT (by subtracting exercise energy expenditure - physical activity energy expenditure).

When it was all said and done, the lesser group added an average of 105 minutes of walking to their weeks, while the higher group added 160 minutes to their weeks.

There was a teeny tiny bit of weight lost in both groups (1.7lbs), and a tiny change to body fat percentage (-0.7%), but there were no between group differences. Expectedly, V02max improved more in the larger amount of exercise group.

What didn't change?

Everything else.

Despite marked increases in intentional exercise, and marked differences in adhered to doses of exercise, there were no differences found for participants' total daily energy expenditures, resting metabolic rates, NEAT, non-exercise physical activity or even total physical activity.

These results changed some when they further analyzed the data as they determined that those patients with higher baseline levels of physical activity showed lower levels of NEAT (important to note, difference did not reach statistical significance) post 4 months of exercise, whereas those with lower levels of baseline activity experienced decreases to resting metabolism with exercise (authors suggested latter might be due to weight loss, but given how small weight loss was, I find this confusing as the RMR drops were not small).

All this to say when it comes to exercise and its impact on calories burned, it's clearly far from a simple math formula. It's also incredibly unfair to weight. But as always, when it comes to improving health, nothing beats it.

[Thanks to Matt Woodward for sharing this study with me]

If Pokémon Go Doesn't Keep People Moving, What Chance Does Public Health Have?

You remember Pokémon Go, right? I remember when it launched I was giving a talk in LA, and honestly it seemed as if the entire city was trying to catch Pokémon. Flash forward a year or so and I can't remember that last time I saw anyone trying to catch one.

I was curious about whether or not people were still playing and so I hunted around online a bit and found a few articles.

What I learned was, during that launch time last summer there were 28.5 million global daily users. That same article has it that by January, just 5 months later, the number of daily players had dropped by 80%.

Or has it dropped even further than that? Certainly if this Reddit thread can be believed, it has, as the thread asserts that a large percentage of active players now are

• "Bots used by scanners -- Who knows how many bot accounts are out there.
• Multi-account players -- Based on concerns of gym shaving, this appears to be prevalent, but there is no way to determine how many "alt" accounts are out there.
• Account Sellers -- Overlapping 1 and 2, there are many accounts that are floating around out there for sale that have been either leveled by bots or by hand."

All this to say, that the 5 month drop off rate of the most viral and widely launched augmented reality game is somewhere between 80 and 90%, strikes me as more evidence that rather than promoting flashy, feel-good, new online tools and commercials that stand virtually no chance at inspiring sustained behaviour changes, we need to spend our energies and efforts on environmental engineering to squeeze more activity out of our normal lives (eg. cycling and walking infrastructure, tax incentives or disincentives, stairwell renovations and signage, etc.), forcefully building the opportunity for exercise back into our kids' lives (eg. the return of proper school recess), and lobbying our politicians for same.

And maybe it's just my cynicism, but I do find it odd that despite our global and possibly total failings at inspiring intentional, because-it's-good-for-you, behaviour change, both with food and fitness, that as a society we still seem to be clinging to the notion somehow, someone, somewhere, will figure out the golden message, app, or website that will set us all straight. At this point, and certainly in the developed world, it's hard to imagine that the problem is a lack of education as to the benefits of exercise and/or a healthful diet.

Forks vs. Feet for Obesity: The Great Debate Part II (Next Week in #Toronto)

Which is more critical to obesity treatment and prevention - our forks, or our feet?

That's the subject of my upcoming debate with the inimitable Dr. Bob Ross.

It's actually a redo of our prior debate from 2011 on the same topic (which you can watch here if you'd like).

It's being presented by the Toronto chapter of the Canadian Obesity Network (CON) and it's taking place at 5pm on Tuesday June 6th in the Ben Sadowski Theatre of Mount Sinai Hospital.

Tickets are just $15 with proceeds going towards the support of the chapter's activities (and you can buy them in advance by clicking here).

My prediction?

There's going to be far more agreement than you might imagine.

Also?

It should be a lot of fun.

Hope to see you there!

Childhood Obesity, Bullying, Shame and Inactivity (In That Order?)

Last week, while enjoying the Canadian Obesity Network's biennial Summit, I attended a lecture about childhood obesity and physical activity. One of the slides presented demonstrated a robust correlation between weight and inactivity - and the thrust of the lecture was that there was likely a strong element of causality to it.

That correlation certainly fits with the findings of the Coca-Cola funded ISCOLE trial, which examined the relationships between lifestyle and weight among over 6,000 9-11 year olds from 12 different countries and found the greatest correlation with weight was with physical activity.

But I do wonder about directionality.

Working for the past 4 years with the parents of children with obesity, I can tell you that it's an incredibly common story to hear about the kid who used to love dance, or hockey, or soccer, or swimming - who suddenly stopped wanting to participate. Why'd they stop? Maybe because they no longer felt comfortable.

What do I mean? Take a moment and consider how you might feel about physical activity as a child if:

• Someone had made fun of how you looked in your gym clothes or uniform
• Someone had laughed at how you jiggled when you ran
• Whether anyone had ever said anything, you were self-conscious about those two points above
• You had experienced weight-related bullying in the past that made the likelihood of being bullied while exercising a credible possibility
• You were one of the slowest kids on your team, or on the track, or in the pool
• No one ever passed the ball to you

And that's just regarding organized play and sport. The same questions would apply to active play, and so too would the question of whether or not you had friends to play with, as sadly, especially among kids with the highest weights, many don't.

Research on the impact of childhood bullying on physical activity exists, but it's scant. That said, it definitely supports the notion that children who are victims of bullying are less likely to be physically active (Study 1, Study 2, Study 3). Given that weight is the number one source of childhood bullying (by a substantial margin), I would love to see bullying explored as a co-variable in studies like ISCOLE, where their findings are often utilized to infer that inactivity leads kids to develop obesity, and not that obesity leads kids to become inactive. That latter directionality was found in the study Fatness predicts decreased physical activity and increased sedentary time, but not vice versa: support from a longitudinal study in 8- to 11-year-old children, which concluded,

"Our results suggest that adiposity is a better predictor of physical activity and sedentary behavior changes than the other way around."

The ISCOLE trial, in its introduction, speaks to the existence of bullying consequent to childhood obesity, as well as obesity related social isolation - but neither are considered by the authors as possible confounding variables when it comes to inactivity. In fact, in the study's entire discussion, this is the only mention of correlation not necessarily representing causation (for any of the examined associations)

"Finally, given the cross-sectional study design, cause-and-effect inferences cannot be made, and we cannot exclude the possibility that unmeasured confounding variables may explain some of the observed relationships."

But given the plausible path from obesity to inactivity, along with the impact these sorts of studies have on public health and policy discussions, I sure wish it had included a more fulsome discussion therein.