More evidence comes in which suggests exercise does not do much in the weight loss stakes

It’s mid-January, and no doubt quite a lot of people will be persisting with New Year resolutions that have something to do with their health, with ‘losing weight’ being generally high on their list of priorities. Exercise is usually thrown into the mix here, and while walking my dog this morning I witnessed a distinct upturn in the number of joggers I normally see, despite the fact that there is quite a lot of snow and ice on the ground.

I am very much an advocate of exercise, and it certainly has a big part to play in fitness and health. However, I don’t rate it if weight loss (and even fat loss) is the ultimate aim. For more on this, see a previous post from August which attempts to explain why increasing exercise and activity is highly unlikely to lead to meaningful weight loss.

I was reminded of the relative inefficiency of exercise in terms of weight loss by a study published very recently in the journal Obesity [1]. It basically looked at the relationship between exercise and not weight loss, but weight regain (the regaining of weight after successful weight loss). The study assessed more than 4500 pre-menopausal women who had successfully lost weight (more than 5 per cent of their body weight over a two-year period), and then were followed-up over a 6-year period. Individuals who gained more than 30 per cent of the weight they had lost were defined as having been subject to ‘weight regain’.

The results of this study found that higher levels of physical activity were associated with less weight regain. For example, an increased in acitivity of 30 minutes per day was associated with reduced regain of 1.36 kg (3 lbs).

Risk of weight regain was reduced by about 30 per cent in women who maintained exercise at about 30 minutes or more per day.

More strenuous exercise was associated with more marked benefits. For example, jogging or running was associated with a reduced weight regain of 3.26 kg (7 lbs).

This study was epidemiological in nature, and therefore can only tell us about relationships between exercise and weight, and not that exercise definitely prevented weight regain. It might be, for instance, that those who exercise more also were more careful with their diets, and this accounted for some or all of the apparent benefit associated with exercise.

However, assuming for a moment that exercise did directly bring about the weight benefits seen, it occurs that there’s a lot of exercise going on here for relatively little benefit.

This study suggests that if, for example, you stepped up your exercise by 30 minutes per day over a six-year period, you could expect to be about 3 lbs lighter for it. That’s over 1000 hours of exercise to be not very much lighter at all.

The results are better for more strenuous activity, but a lot more effort would have to go into this too. Somehow, the thought of jogging or running for more than 1000 hours to be, at the end of it, 7 lbs lighter does not fill me with enthusiasm.

Let’s not draw too many conclusions from this study because, as I said, it is epidemiological in nature. However, its results do at least support the idea that, as strategies go, exercise is not particularly effective for the purposes of weight loss. Also, as the post I link to points out, intervention studies (studies which essentially compare the weight loss effects of exercising with non-exercising) have found the same thing. Taken as a whole, the logical conclusion is that exercise does not do much for weight loss.

This evidence does not, in my opinion, provide a good reason not to exercise. Activity and exercise likely enhance health and well-being in a variety of ways. However, I do think it’s important to be honest about what benefits are likely from any intervention. So, by all means take exercise, and preferably choose forms of this that are enjoyable and sustainable. And by all means lap up the psychological and physical benefits that can come as a result. Just don’t expect the exercise you take to help you lose much weight, that’s all.


1. Mekary RA, et al. Physical Activity in Relation to Long-term Weight Maintenance After Intentional Weight Loss in Premenopausal Women Obesity 2010;18(1):167″174

13 Responses to More evidence comes in which suggests exercise does not do much in the weight loss stakes

  1. David 13 January 2010 at 2:03 am #

    Hello, I am an european health/nutrition journalist and I like your blog since I am an advocate of a low-moderate carb lifestyle.

    I would want to ask you about some personal opinion about Zone Diet, a moderate version of low-carb diets. More or less I go on a Zone Diet modified with also saturated fats (butter and coconut oil) because of influence of Weston Price Institute on me. Many people can go on on a very low carb diet, but I prefer a moderate (low glycemic) carb diet like Zone. I think for a general recommendation is better a low carb but not ketogenic diet. More or less it is the modern version of Atkins diet, which allows to eat many fruits in a day.

  2. Jamie 13 January 2010 at 3:42 am #

    Dr Briffa,

    As you know, there are many ways in which one can perform ‘exercise’, so perhaps it isn’t so much that exercise isn’t particularly good for weight reduction, but the way in which people engage in & structure their exercise routines. I’ve worked many years as a PT & come from a university background. For the most part, much of what I was taught & prescribed was based on ASCM guidelines – chronic cardio. That is training in a no mans land that, whilst perhaps increasing fitness, also significantly increases appetite for many.

    Like you I suspect, I am a little more ‘primal’ in the way I structure things these days, tending to prescribe lots of low level movement, interspersed with ‘sprinting’ & lifting heavy things. Unfortunately for the vast majority of ‘resolution exercisers’ it is far easier for them to plod on the treadmill, bike, or whatever for 20-40 mins a couple of times per week, do some sit ups, & kid themselves it is making a difference (or at least use this as justification for a food reward) than find a way to move lots daily, & move fast/lift heavy every few days.

  3. Catherine 13 January 2010 at 9:40 pm #

    Hi John

    I really enjoy your blog but I wanted to raise a couple of points where I wonder if other factors need to be taken into account?

    a) Role of exercise in weight-loss
    I know myself that the only times I have been able to lose weight or keep it under control were when I was exercising regularly. Undoubtedly, there is a psychological element: attaining food goals requires constant vigilance, whilst going to the gym takes an hour but the glow of satisfaction lasts for at least 24 hours! Whilst I agree with the arithmetic, is is not reasonable to compare the food intake/energy expenditure equation with money? It is possible to live on social security benefits, but it’s extraordinarily difficult to keep your expenditure down to that level. If you have a bit more money coming in, it’s extremely unlikely that you will live on the lower amount and save the difference, but it definitely makes it easier to live within your means. To me, dieting is the same. Living on, say, 1200 calories a day is virtually impossible – you have to watch absolutely everything you eat and you can kiss goodbye to your social life – but do 300 calories worth of exercise and 1500 is much more doable – you can even go out and enjoy yourself a bit!

    b) breakfast (not dealt with in this post)
    Is it not more likely that people who don’t eat breakfast are fatter not because they don’t eat breakfast but because they’ve eaten more the previous evening and so aren’t hungry at breakfast time? Eating breakfast when you aren’t hungry seems mad to me, as does the implication that if you haven’t eaten breakfast the only possible outcome is to reach for a doughnut at elevenses – surely the logical response is to eat something sensible when, but not before, you are hungry?

    I’ll be interested to see what you and others have to say!


  4. Haggus 13 January 2010 at 11:19 pm #

    I dropped the first 60 of my 115 drop without lifting a finger. It all came off via Atkins. Since then, I have added exercise (play) simply because I enjoy it and have a body now, at 176lbs, that can handle it.

    Today. I’m of the opinion that while some might be able to lose weight exercising (I’ve met them), it’s a lousy way to lose weight.

  5. Rowena Payne 15 January 2010 at 4:33 pm #

    Vindication! I have exercised a lot all my life, swimming (miles) and walking (miles) and love it. The major benefit is relaxation and time to myself! However have never been able to lose weight in any significant way and am comforted to read your blog re this!
    Will still be exercising but without worrying now about weight loss.
    Thank You

  6. Dr John Briffa 15 January 2010 at 5:35 pm #


    “Will still be exercising but without worrying now about weight loss.”

    For me, that’s the point: to have individuals get fit and healthy doing something they enjoy (hopefully) and not worrying about ‘burning calories’ or whatever. Enjoy.

  7. Dr John Briffa 15 January 2010 at 5:40 pm #


    I think the need for carbohydrate (and the other macronutrients) and our ability to tolerate them varies from person to person. I’m an advocate of low-carb generally, but there’s no doubt for some, it’s possible to go too low. For those individuals (perhaps including you), a more moderate approach (e.g. Zone) might be better.

    I am very much into the idea of people trying things to see what works, and then adjusting as necessary.

  8. Gary 29 January 2010 at 10:39 pm #

    Part of the problem when looking at many of the studies concerning weight redution is that they rarely distinguish from which body compartment the weight loss is comming from.
    The concerns I would have, are that those attempting weight reduction without activity are more prone to muscle catabolism. Not a good thing in the long term…you will very likely end up weaker with less muscle mass as a result of dieting without right activity. Who wants bingo wings.. not attractive.
    So my advice would be preserve that hard won muscle at all cost. Its your most metabolically active tissue. Dont diet without activity. But don’t rely on activity alone to strip the weight.

  9. Betty Davidson 4 March 2010 at 12:25 am #

    Dear John
    I was so pleased to read your article entitled ‘Carb Crash’ in the Observer a few years ago. I identified completely with it as it was more in keeping with the diet I was put on in 1953 when first diagnosed with diabetes.
    I have photocopied it and passed it on to other diabetics but people find it hard to believe when the dieticians are still pushing the carbohydrates.
    At that time I received three rations of meat,butter and cheese but no sugar or confectionery ( if it had still been rationed).


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