Should we ditch the Fitbit?


Should we ditch the FitBit?

If you’ve read my blog before, advance warning: this is a different post from my usual ramblings on the highs and lows of running. And it may get a bit ranty. Sorry.

It was inspired by this recent article in the Washington Post by Dr. Aseem Malhotra. Those with good memories may recognise Dr. Malhotra’s name as one of three cardiologists who were all over the news last month after writing in the British Journal of Sports Medicine that activity isn’t part of the solution to obesity.

Now Dr. Malhotra’s at it again. The gist of the WP piece is this:

We’re in the middle of an obesity epidemic. Nearly a third of us are overweight or obese, and no country is successfully tackling the issue.

This is happening despite the current fitness industry boom and the rise in FitBits and other activity trackers.

And that’s because it’s a myth that sitting on our butts all day long has anything to do with why we’re getting fatter.

“Exercise – no matter how many gym memberships you buy or how often you wear your Fitbit – won’t make you lose weight”.

Leave aside that regular exercise helps prevent coronary heart disease, diabetes, and a heap of other diseases. Forget that as we get older, keeping physically active has a big impact on our quality of life. If you want to lose weight, save yourself the effort and just stick to calorie counting.

For sure, you ‘can’t outrun a bad diet’. If your post workout routine involves diving face first into a bucket of donuts, and not shifting from the sofa until your next gym session, you probably need to rethink your fitness strategy.

But does activity really have no influence on weight? Hmmm.

Now Dr. Malhotra is an esteemed cardiologist. And I’m not. But this just didn’t make sense to me. We’ve heard for so long that dieting alone isn’t the key to maintaining a healthy size. And if activity really has no impact on weight, why is it that athletes can eat thousands of calories a day without putting on pounds, and then get fat as soon as they stop training?

So I decided to dig deeper. Bear with me.

Full disclosure: I teach Chi Running technique for a living and I’ve been a runner for more than 20 years. So yes, I have an interest in showing exercise is worth the effort.

To begin with, I trawled through all those links that Dr. Malhotra helpfully provided, and discovered that the ‘evidence’ isn’t as cut and dried as he’d have us believe.

That 2011 study that found that people who dieted lost more weight than those who combined diet and exercise? Firstly, the study participants were frail, obese over-65s, which may possibly, perhaps, maybe have had some influence on how actively they could participate in an exercise programme? And while the study did show that the group that dieted lost the most weight, they also lost the most mineral bone density. And the most lean body mass. That’s muscle to you and me. So maybe not such a great win for dieting after all.

Then there’s the survey of millions of Americans that found that an increase in activity between 2001 and 2009 was matched by an increase in obesity. For starters, weight and activity levels were self-reported, which makes them just a little bit iffy. And interestingly, not only did respondents say that they were moving more, they also claimed to be eating less over the lifetime of the study. So if you believe the results, cutting back on calories doesn’t seem to have had much of an effect on obesity levels either. On the flip side, the results do suggest a connection between exercise levels and weight. Four of the top 10 counties that reported the lowest levels of sufficient physical activity for both men and women also appeared in the top 10 most obese counties. Coincidence, much?

And then there’s the ‘comprehensive literature review’ from 2013 that shows that exercising plus dieting doesn’t help us lose any more weight than dieting alone, because the more we exercise, the hungrier we get, and the more we eat.

Now, I’ll be honest. I didn’t read through all the references listed in this meta study. Well, there were 45 of them and I’m not quite that dedicated.

But the ones I did click through to again painted a slightly more nuanced picture than the headlines would have you believe.

Sometimes people lost more weight with exercise than by dieting. Sometimes they didn’t. But they did lose more inches off their waistline. Which means less visceral fat. This is a Good Thing and goes to show the risk of discussing obesity just in terms of weight gained and lost.

There’s no doubt that we have to do something about our calorie-dense, nutrient-poor diet. And the idea perpetuated by food industry advertising that exercising gives you a free pass to eat and drink junk needs to be exposed for the nonsense that it is.

But is trashing exercise as futile in the fight against our ever-increasing waistlines the answer?

We’ve already been made confused and cynical by the mixed messages we’ve had on nutrition over the last few decades. Wasn’t polyunsaturated margarine supposed to be the healthy option? So how does creating the same uncertainty over exercise help?

In my merry jaunt through scientific papers, I found plenty of studies that say that exercise does help in losing weight and keeping it off. Like this one. And this one. And this one.

So it seems that maybe we should actually be doing what health professionals have been telling us to do for a while: eat less sugar and processed foods; eat more fruit and veggies; and move more.

But I guess that’s a headline that doesn’t get you an article in the Washington Post.

Photo Credit: Christi @ Love From The Oven via Compfight cc


  1. Thanks for having a look at the evidence.

    I didn’t bother because I have tried and failed to lose weight through dieting but always found that running works for me. Mu rule of thumb is that a good week should include 25 miles run and energy expended running and walking equal to the energy of a kilo of fat. Not demanding if you are heavy & already walk!

    • Thanks Matthew. Whatever the evidence, I think we have to remember that any study results are based on statistical averages, and we’re not statistical averages. Finding what works for each of us is key. Glad to hear you’ve found an approach that suits you!

  2. Another issue that escapes those who simplistically say “a calorie is a calorie” is the gut biome (mostly bacteria) which can influence how we interact with food. Example: find identical twins, one thin and the other fat and take some of their feces and put it into the colons of mice. All mice given identical diets, but those which have received fat-twin poo will get fatter. The science is at an early stage but it appears that the biome interacts strongly with the immune system and this holds out the hope that the biome causes and can cure autoimmune diseases. Tim Spector’s ‘The diet Myth’ is good on the biome.

    • Fascinating stuff, Matthew! It will be interesting to see how the science develops. Our bodies are individual and unique in so many ways, and perhaps we won’t really see an effective solution for the obesity epidemic until we better understand how to treat the individual rather than the statistic.

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