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New study suggests exercise may play more important role in weight loss

Azdak
Azdak Posts: 8,281 Member
edited May 2016 in Debate Club
One of the most consistent phrases used on MFP is "exercise is not necessary for weight loss". The underlying principle is that all one needs to lose weight is a calorie deficit, and that exercise is for "fitness only".

The point of this statement (I think), along with the "you can outrun a bad diet" is to emphasize that a calorie deficit is the only real way to lose weight, and that exercise only, without controlling food intake, is likely to be unsuccessful. I have seen some people write that exercise is really only useful in order to be able to eat more food (and for fitness).

The reference I saw today--

http://www.ncbi.nlm.nih.gov/m/pubmed/27169833/

suggested that, while an energy deficit is still necessary for weight loss, it might be better to create that deficit via a combination of increased food intake AND increased exercise, rather than just through diet alone. This was referred to as "high energy flux".

Example: if one's TDEE was 1700 cal/day and one ate 1200 cal/day with no exercise to create a 500 cal/day deficit, it might be better to add 300 cal/day of exercise for a TDEE of 2000 cal/day and then eat 1500 cal/day.

At first glance, this might seem to violate the laws of CICO, but it doesn't really. The authors suggest that the improved loss seen by the "high energy flux" plan actually increases BMR, which then increases actual TDEE--basically you are getting the extra boost from exercise (and maybe even the thermic effect of food).

As always, this is just one study, and I am taking this solely from the abstract. I suspect if one reads the whole thing there are a ton of caveats and methodology concerns, because these are not easy to do. So, as always, one study should not be seen as a criticism of anyone's current plan.

What I do think it does, however, is put a notch on the board slightly in favor of the "diet and exercise" approach vs the "diet only" approach, and maybe give some motivation to those of you out there working out and working hard that your approach may be giving you more than just "fitness"benefits.
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Replies

  • middlehaitch
    middlehaitch Posts: 8,481 Member
    edited May 2016
    *i have not read the article yet.

    ( big delete)

    Ok I read the article.
    My post was out of context.

    Sorry, h.
  • stevencloser
    stevencloser Posts: 8,911 Member
    edited May 2016
    Sounds like the usual to me.
    My predictions: The increase in BMR isn't going to be practically significant, only statistically (something like an extar 50 or so), the way they measured does not allow for implications of causation to be made, i.e. people who exercise very regularly pay more attention than people who just want to lose weight and aren't too much into that healthy lifestyle stuff, leading to the first to be overall more successful.

    "Adolescents (n = 154) and college-aged women (n = 75) underwent 2-wk objective doubly labeled water, resting metabolic rate, and percentage of body fat measures at baseline. Percentage of body fat was measured annually for 3 y of follow-up for the adolescent sample and for 2 y of follow-up for the young adult sample."

    That study design does just not allow for any conclusions like the ones they did. The only thing that shows is "People who exercised ended up with better body composition".
  • ReaderGirl3
    ReaderGirl3 Posts: 868 Member
    edited May 2016
    I didn't exercise at all during my weight loss phase (still don't now in maintenance, for the most part). So yeah, for me personally-exercise was not a factor at all. I lost at a steady rate, didn't experience any stalls and all my health markers improved by quite a bit. I'm 3 years into maintenance now. I've never had my bf% professionally taken but again, going by my health markers and my doctor, and then my bmi, I'm not too concerned about it.
  • fr33sia12
    fr33sia12 Posts: 1,258 Member
    I don't know if I have this right, but want to check. When I get to my goal weight my BMR will be 1,359 calories, that's if I do nothing but sit all day right?
    So if I wanted to eat say 1800 calories a day to maintain my weight I'd have to exercise to burn 500 calories?
    But the BMR is just sitting doing nothing right, so what about when I'm moving around, cooking, cleaning, tidying and the day to day things you do in between sitting. Is it just a case of trial and error to see how many calories you can eat in maintenance if you don't exercise, yet move around during the day?
  • lemurcat12
    lemurcat12 Posts: 30,886 Member
    edited May 2016
    I don't know if I have this right, but want to check. When I get to my goal weight my BMR will be 1,359 calories, that's if I do nothing but sit all day right?
    So if I wanted to eat say 1800 calories a day to maintain my weight I'd have to exercise to burn 500 calories?
    But the BMR is just sitting doing nothing right, so what about when I'm moving around, cooking, cleaning, tidying and the day to day things you do in between sitting. Is it just a case of trial and error to see how many calories you can eat in maintenance if you don't exercise, yet move around during the day?

    To add to what seska422 said, the normal multipliers for estimated BMR are 1.2 for sedentary and 1.5 for lightly active (think about 10,000 steps for this). So if you are sedentary (which includes some normal movement, like that you mention), maintenance would still be about 1630, and if lightly active more like 2000. I've found those numbers (well, based on my own estimated BMR, which is lower) to be pretty consistent with reality.

    That aside, the BMR is an estimate, the activity factors are estimates, and you will have much better information when you are at goal weight if you've been logging consistently, as you will be able to figure out your actual TDEE.
  • fr33sia12
    fr33sia12 Posts: 1,258 Member
    Thanks everyone, I'll certainly check back when I reach my goal!
  • jgnatca
    jgnatca Posts: 14,464 Member
    Exercise is my favourite thing in this fitness game. But it has to be put in context. How many times has a person posted that they worked themselves in to exhaustion and actually gained weight? They are naturally overwhelmed if even more exercise is needed to lose. But of course to lose, the answer is in the kitchen.
  • EvgeniZyntx
    EvgeniZyntx Posts: 24,208 Member
    edited May 2016
    I've posted previously that exercise causes metabolic changes that are a positive, if small, contribution to increased energy use by the body during weight loss.

    If someone can't or doesn't want to exercise to during weight loss, well, I understand that decision since adding a lot might be difficult and overwhelming and it might actually create mental barriers of "too much = impossible". But the most effective methods of weight loss and body composition include some form of calorie restriction AND exercise.

    The problem with the term "exercise" is that it assumes a specific set aside time for doing some sort of specific program in a specific space. It can be that but exercise can just as easily be part of an active life style of doing things you enjoy. A long hike in the woods, cycling to work, playing in the park are all exercise.

    Stay active, do things, both planned and unplanned exercise helps.

    (edit: here is the thread I posted on this subject - many of the responses were disappointing... http://community.myfitnesspal.com/en/discussion/10343378/beyond-a-calorie-deficit-exercise-is-good-for-weight-loss/p1)
  • ekat120
    ekat120 Posts: 407 Member
    I just skimmed the full text. Energy flux was measured as intake+burn (e.g., someone who eats 1500 and burns 1500 has an energy flux of 3000, whereas someone who eats 2000 and burns 2000 has an energy flux of 4000). There was a moderate correlation of ~.3 between energy flux and RMR, meaning that "energy flux" explains about 10% of the variation in RMR (resting metabolic rate) from person to person. The association between energy flux and body fat % at follow-up was about the same size, with higher energy flux predicting lower body fat % (after controlling for energy balance, or the difference between what people burned and ate).

    Looking at the plots of the data, there was a lot of variation from person to person. My own conclusion would be that being more active does help on average (by increasing RMR), but not a ton, and it varies depending on the person. Note that just because it helps doesn't mean that you can't lose weight without being more active (meaning arguments of "I lost weight just fine without exercising" don't contradict what the study found), just that it can help.

    Interesting study, thanks for posting it :)
  • CaptainJoy
    CaptainJoy Posts: 257 Member
    Exercise is extremely important when in a calorie deficit because without it you can actually lower the rate you use calories while resting. This was proven by a U.S.government study done in 2009. Ci/co works but what good is losing the weight if you're just going to put it back on because you are no longer burning the same amount of calories at rest as you were before you lost the weight?

    https://www.nia.nih.gov/newsroom/announcements/2009/05/study-shows-metabolic-adaptation-calorie-restriction
  • seska422
    seska422 Posts: 3,217 Member
    CaptainJoy wrote: »
    Exercise is extremely important when in a calorie deficit because without it you can actually lower the rate you use calories while resting. This was proven by a U.S.government study done in 2009. Ci/co works but what good is losing the weight if you're just going to put it back on because you are no longer burning the same amount of calories at rest as you were before you lost the weight?

    https://www.nia.nih.gov/newsroom/announcements/2009/05/study-shows-metabolic-adaptation-calorie-restriction

    You aren't going to be burning the same amount of calories at rest anymore anyway because your body is smaller than it was when you were overweight. If you go back to eating the way you were eating before you lost weight, you'll regain weight whether you exercise or not.

    Some people can't or won't exercise. They can lose weight too. Is it better to exercise? Sure. Is it required to exercise? No.
  • JeromeBarry1
    JeromeBarry1 Posts: 10,182 Member
    In what way is this not similar to what the bodybuilders call "bulking"? I.E., eat more , exercise with progressive resistance, build muscle, increase BMR.
  • CaptainJoy
    CaptainJoy Posts: 257 Member
    @seska422
    "Some people can't or won't exercise. They can lose weight too. Is it better to exercise? Sure. Is it required to exercise?"

    Yes they can lose weight solely by cico. It's not required to exercise to simply lose weight. It's just harder to maintain because once they reach their goal they will gain if they eat the amount of calories allotted for their age/sex/weight. Their maintenance needs will be lower than the average.
  • ReaderGirl3
    ReaderGirl3 Posts: 868 Member
    edited May 2016
    CaptainJoy wrote: »
    Exercise is extremely important when in a calorie deficitbecause without it you can actually lower the rate you use calories while resting. This was proven by a U.S.government study done in 2009. Ci/co works but what good is losing the weight if you're just going to put it back on because you are no longer burning the same amount of calories at rest as you were before you lost the weight?

    https://www.nia.nih.gov/newsroom/announcements/2009/05/study-shows-metabolic-adaptation-calorie-restriction

    May I ask how long you've been in maintenance? 3 years into maintenance here, and I didn't exercise at all during my weight loss phase. My TDEE is spot on and has been since I started this whole thing back in 2012.