“Exercise not helpful for weight loss!” – so read the headlines on a recent newsflash that just surfaced in my inbox.
As you can imagine, I received a flurry of emails asking me to speak to the article. It took a little bit of sleuthing, but a persistent search turned up the pdf of the research article in question.
Here are some factoids and bits of analysis for you to consider.
You can’t out train a bad diet
When it comes to weight loss, we know this is absolutely true:
The energy balance equation suggests that energy intake and energy expenditure occupy equivalent roles in determining energy balance, when in fact the factors governing energy intakes influence the energy balance far more powerfully than the factors determining resting energy expenditure.
Flatt JP. Issues and misconceptions about obesity. Obesity (Silver Spring). 2011 Apr;19(4):676-86.
Yet the conclusions of the study reported upon in the “Exercise not helpful for weight loss” alert actually read thus:
Our study showed that increased physical activity alone has a small impact on obesity prevalence at the county level in the US. Indeed, the rise in physical activity levels will have a positive independent impact on the health of Americans as it will reduce the burden of cardiovascular diseases and diabetes. Other changes such as reduction in caloric intake are likely needed to curb the obesity epidemic and its burden.
Dwyer-Lindgren L, Freedman G, Engell RE, et al. Prevalence of physical activity and obesity in US counties, 2001-2011: a road map for action. Popul Health Metr. 2013;11:7.
This is not the same as saying ‘exercise is not helpful for weight loss’.
It simply means you can’t out train a bad diet.
Read the fine print
Research always needs to be examined for what possible interpretations of the data. Especially when it comes to self-reported data. Apparently, the researchers suspect the self-reporting element may have important bearing on the results of this study.
In this study, subjects were asked to self-report on 1) height and weight, from which body mass index was calculated, 2) activity levels, and 3) calorie consumption. To assess the leisure time physical activity, the respondents were asked, “During the past month, other than your regular job, did you participate in any physical activities or exercises such as running, calisthenics, golf, gardening, or walking for exercise?”
“Sufficient activity” was defined as 150 minutes of moderate activity a week – again, self-reported. Amount of activity reported varied widely between responding counties across the U.S. Covariates – other factors were taken into consideration to help evaluate the data – were considered, such as access of specific populations to health care, assuming that those with access may be in the care of health care providers that may influence their decisions about healthier diet and exercise habits. Other covariates included level of education, racial composition, pollution, and employment.
About 3.7 million adults aged 20 years or older participated in the study from 2000 to 2011, and 30,000 adults aged 20 or older participated from 1999 to 2010.
When you read the fine print, all kinds of red flags pop up – all connected to human behaviors.
Self-reported declines of mean adult caloric intake dropped from 2,269 kcal/day in 2003–2004 to 2,195 kcal/day in 2009-2010. These self-reported figures for caloric consumption are “markedly lower than average caloric availability in the US, which exceeds 3,750 kcal/day.”
In other words, the subjects have some ‘splainen to do: The increases in obesity, decreases in caloric intake, and increases in physical activity seen here don’t add up and raised the eyebrows of the research team. As noted in the report, obese individuals are more likely to under report their calorie intake. Thus it is quite possible that as obesity levels increased, calorie reporting may have been further underestimated. If calorie intake is greater than that needed to remain in energy balance, then it can easily offset the energy consumed by increased activity.
In addition, the increasing social pressure to be more active can lead to fudging on self-reporting:
The increase in self-reported physical activity could also be due to increased positivity bias. Given increased public awareness campaigns for physical activity, it is possible that individuals have become more likely to report positive behaviors even if they have not increased their physical activity. Our sensitivity analyses of different ways of constructing sufficient physical activity show that the national trend may be leveling rather than increasing.
It makes a difference how you read the data
Remember the covariates I mentioned above? Though there was overall a low correlation between change in the level of physical activity and obesity in from 2001 to 2009, for every 1 percentage point increase in physical activity, obesity prevalence was actually 0.11 percentage points lower. This result is considered significant when controlling the data for a number of other covariates: percent rural, change in poverty level, change in unemployment, and an increase in the number of doctors in the given population. In other words, the decrease in obesity correlated positively with increased physical activity in counties where education, health care, and economy showed an improvement.
Exercise does a lot more than burn calories
While noting the flaws of this study – some of which I’ve explained above – in Conclusions, the team says that the rise in physical activity levels will have a positive independent impact on the health of Americans by reducing the burden of cardiovascular diseases and diabetes. At the same time, other changes – such as reduction in caloric intake – are likely needed to curb the obesity epidemic.
Exercise builds brain power, enhances self-esteem – in those of any size – and builds physical confidence. We know that people engaged in regular exercise programs feel more in control of their dietary choices. And people with better means, and increased access to health care – an improved standard of living and better education – shows up in improvements in health. This powerfully underscores the need for ongoing community education and the importance of improved standards of living.
And it tells us – and I’ll say it again – that you can’t out train a bad diet.
Bottom line? Keep moving – there’s a lot more at stake here than just weight loss – and remember that you carve your figure with your fork.
P.S. To help illustrate the point, watch this short video by Brad Pilon and Craig Ballantyne. Watch while during this 2 minute segment, Brad consumes 1,000 calories of pizza and root beer while Craig, running at an 11-mile-per-hour pace, “runs off” under 50 calories in the same amount of time.
This is excellent Lani! I love the way you simplify things. I too had seen the article and didn’t know what to think. Thanks to your analysis, I understand much better.
Thanks for taking the time to put this together.
I’m so glad it is helpful! Reading between the lines on research is always enlightening, but it’s not always an easy task!
I appreciate you stopping by to share your thoughts.
So we shouldn’t just give up on exercise? Of course not – and thanks for, as always, your encouraging and enlightening words.
What a timely response – thank you.
Tom – thanks so much for sharing your thoughts. I appreciate!
I think if they had titled it: “Exercise is not necessary to lose weight, but it IS necessary to stay fit” as Dr. McDougall States, it would have made more sense.
Nancy, your title might indeed be better. At the same time, it invites more questions – exercise protects muscle mass during weight loss inspired by reduced calorie intake. We can simply lose weight, or we can do it in such a way that doesn’t threaten our lean body mass as does simply calorie restriction alone.
PLUS as the research points out, the exercise DID make a difference for those segments of the population that were upwardly mobile. Evidently education and health care make a difference, and that is overlooked by the alarmist ‘exercise not helpful for weight loss’ headline.
Thanks so much for your contribution to the conversation today Nancy. I really appreciate it!
Great article, Lani!
Weight loss will always come to calories in vs calories out. People that continue to fill their bodies with junk and think that exercise is their saving grace will always hit a wall, blame their genes, and give up. Exercise does so much for my well being that has nothing to do with my weight. I feel great physically and mentally, and I can tell when I’ve missed out, even if only for a couple days. (My bike got a flat tire, so I had to drive the 13 miles to work the past 2 days. Getting it fixed this weekend though.) 🙂
Exercise will always be a huge part of my well being.
Thank you so much for posting your thoughts. The last thing we need is people throwing up their hands and ditching their workouts with the idea that ‘it won’t help me anyway!’ You underscore the value of moving your body. Increased well being from being physically active translates directly to making better choices on our plates. And that’s just the start.
Sorry to hear about the bike, may she be healed quickly!
Thanks for this, Lani! Throughout the entire article, I was going to comment with a link to the very video you have at the end! I think that is a hoot–and something I have shown to many of my coworkers who claim they are going to “go to the gym” to work off the 3 donuts they just inhaled!
I lost 100 pounds, with my fork, the McDougall way! And during and after the time it took me to lose the weight, I exercised–about 20 minutes a day (plus a quickie or two). Exercise improves my balance, my lung fitness, my energy level, and my mood. Did my little exercises help me lose weight? Sure! Could I have lost that weight,not changing my way of eating, with 20 minutes of exercise every day? Not in a million years! So it’s a synergy–fork and fitness work–I feel, that really helped me succeed.
A dozen ‘bingos!’ to your comments Cloudy!
The synergy is key…and you are obviously one of those in the ‘educated and proactive’ columns as pointed out in the article.
thank you for the inspiration that you continue to be!
Losing weight is all about “won’t” power when it comes to food. But exercise helps to firm up the flab that results after losing pounds. You can reshape your body with exercise along with losing weight.
You have told it like it is. Hurrah!!!
thanks Lani, I to had that article in my inbox and was very surprised that such a thing was published and now after your article I am even more convinced on how silly their article was, I mean lets face it lots of people who would have read the article would have automatically thought how wonderful it was and now they don’t have to worry about having to do any exercise and we sure know how many benefits there are to exercise besides the weight issue, so thanks for all your research and response to this it will certainly clear it up for so many people and I am going to print it out for my scrap book for future reference and if any one come ups with why not to exercise I can show them this, cheers Anna
That’s why I had to speak out. Even though the strongest message of the research was that – as I say – you can’t out train a bad diet, still the headline made it sound like exercise didn’t make a difference – and as you can see in the examination of the paper, there are some instances where it does with weight loss.
Thanks for coming in and commenting Anna – always appreciate!
It is always amazing to me how “twisted” people can make the “truth.” Thanks for being a voice to the uninformed. Having a background in Health and Wellness and being aware that people media people say some really weird things, I knew this article was a misrepresentation. Researchers can manipulate figures to say just about anything they want them to say. And “YES” exercise does have many advantages way beyond weight control.
It does seem to be a full time job to read between the lines, doesn’t it? And it makes you wonder sometimes how they ever come up with decent conclusions with research – there can be so many bearing factors! Especially when it comes to self-reporting, as in this case.
Thanks for your thoughts!
Thank your for all the terrific information. As a super morbidly obese person with severely damaged knees, I workout in the pool. I swim laps and do the large step water walking that you recommend using resistance paddles or gloves to work the arms as well. I do stretching after working out 45-60 minutes. Are there any other exercises you would recommend?
I’m so glad to hear that you are getting regular activity. This is great!
Are you able to walk for a few minutes at a time? It’s important to have weight bearing activity for your bones as well – and even just sitting less and taking standing breaks is a good place to start. Do you have the Fit Quickies book? There is an entire section on simple steps to take to reverse the problems of sedentarism. You could also start doing the targeted exercises that I instruct in detail in the book – and start with them in the water!
Go Hazel go!
Great response, Lani. Thanks for outlining the “fine print.” I thought the headline was attention-catching, and you broke it down very simply. Thanks!