Eating back workout calories?

I've read a lot of posts here that you should eat back anywhere from 50-75% of workout calories. Is there a reason for this? If I've "earned" workout calories (calculated by my FitBit), isn't it better for weight loss not to eat any of those back?

Replies

  • DemoraFairy
    DemoraFairy Posts: 1,806 Member
    50-75% is recommended instead of 100% to account for the fact that many things overestimate exercise calories (Fitbits tend to be more accurate than gym machines or the MFP database, but still aren't perfect).

    The reason you're told to eat them back is because there's already a deficit built into your daily calorie goal - you could lose weight without doing any exercise. If you do too much exercise you can end up in too much of a deficit and end up harming yourself, the same way you would if you were to eat way too little food each day.
  • MKEgal
    MKEgal Posts: 3,250 Member
    My dietician and doctor (endocrinologist specializing in weight issues) both say not to eat exercise calories.
    It's worked for me.

    Most people underestimate what they eat,
    most machines (including MFP) overestimate what you burn.

    If you're really hungry once in a while at the end of the day, or have had a harder than usual workout, have
    1/3 - 1/2 of what you think you burned that day as a snack.
  • MKEgal
    MKEgal Posts: 3,250 Member
    OTOH, if you're losing too fast, or don't feel well, or have other problems,
    then yes, add some of those calories back into your allotment for the day.
  • RGv2
    RGv2 Posts: 5,789 Member
    edited September 2015
    Not necessarily. When you set up MFP, you set up a goal to lose ___lbs per week. MFP gave you a calorie goal via the stats you entered assuming exercise isn't part of that. Let's say our hypothetical person here maintains on 2000 calories per day, and entered in a 1lb per week goal loss (500 calorie defict per day)

    2000 cal maint - 500calories = 1500 cal intake with a 500 cal deifict to lose 1lb per week.

    2000 cal maint + 700 cals from exercise = New maintenance of 2700 calories

    SO--2700 cal maint - 500 cals = 2200 cal intake with a 500 cal deficit to lose 1lb per week.

    Many advise to start with 50-75% because it's all an estimate, so it will take adjusting from there. Exercise calories are fuel and nutrition. If this person with a 2000 cal maintenance ate at the level MFP gave them, 1500 cals, and then burned another 700 off would have them netting at only an 800 calorie intake. At that level, many people are setting their body up for a crash because it is nearly impossible to get the proper nutrition and fuel at that level.

    The less weight you have to lose, like only about 12lbs, exercise calories become more important as you have less energy reserves to pull from.
  • earlnabby
    earlnabby Posts: 8,171 Member
    grg243 wrote: »
    I've read a lot of posts here that you should eat back anywhere from 50-75% of workout calories. Is there a reason for this? If I've "earned" workout calories (calculated by my FitBit), isn't it better for weight loss not to eat any of those back?

    It depends on how you calculate your calories. If you use TDEE (Total Daily Energy Expenditure), your exercise calories are already figured in (BMR + Daily activity + exercise) so you do not eat them back. If you use NEAT (Non Exercise Activity Thermogenesis), your exercise is not accounted for (BMR + daily activity) so you need to add some in.

    The point is to not eat too little net calories. You need to fuel your body properly while maintaining a steady deficit to lose weight. Depending on your weekly weight loss goal, you may have some wiggle room but you don't want to eat too little or you could end up losing lean muscle mass.

  • jim180155
    jim180155 Posts: 769 Member
    edited September 2015
    grg243 wrote: »
    I've read a lot of posts here that you should eat back anywhere from 50-75% of workout calories. Is there a reason for this? If I've "earned" workout calories (calculated by my FitBit), isn't it better for weight loss not to eat any of those back?

    Either way is fine, if it's working for you. I used to eat back my exercise calories and I was still steadily losing weight. And then that kind of quit working.

    I don't know why, but my Fitbit is now crediting me with more calories burned, at about 125 calories per mile walked. That's too much. Also, your body adapts to low-moderate cardio exercise, and after a few weeks or more you'll only burn around 80% of the calories you used to burn for the same effort.

    The combination of the two caused me to hit a plateau. At least I think that's what it was. So I switched to the TDEE method. I lift 5 days a week, something that is factored into my TDEE estimate, and I totally ignore the Fitbit calories. (I still wear my Fitbit and still try to hit 10k steps.) And now I'm back to losing around a half pound a week.

    So eat all the calories, eat a fixed percentage of the calories, or don't eat any. Just keep an eye on your progress and be ready to make an adjustment if and when your weight loss stalls.

    Almost forgot: If you're losing too fast, like more than 2 pounds per week, make an adjustment in the other direction.
  • juggernaut1974
    juggernaut1974 Posts: 6,212 Member
    edited September 2015
    grg243 wrote: »
    I've read a lot of posts here that you should eat back anywhere from 50-75% of workout calories. Is there a reason for this? If I've "earned" workout calories (calculated by my FitBit), isn't it better for weight loss not to eat any of those back?

    'better for weight loss' would be not eating any food at all...but that's obviously ridiculous. You need to adequately fuel your body to function. If you're exercising, you need to adequately fuel both basic body functions AND exercise, hence additional calories need to be consumed.
    RGv2 wrote: »
    Not necessarily. When you set up MFP, you set up a goal to lose ___lbs per week. MFP gave you a calorie goal via the stats you entered assuming exercise isn't part of that. Let's say our hypothetical person here maintains on 2000 calories per day, and entered in a 1lb per week goal loss (500 calorie defict per day)

    2000 cal maint - 500calories = 1500 cal intake with a 500 cal deifict to lose 1lb per week.

    2000 cal maint + 700 cals from exercise = New maintenance of 2700 calories

    SO--2700 cal maint - 500 cals = 2200 cal intake with a 500 cal deficit to lose 1lb per week.

    Many advise to start with 50-75% because it's all an estimate, so it will take adjusting from there. Exercise calories are fuel and nutrition. If this person with a 2000 cal maintenance ate at the level MFP gave them, 1500 cals, and then burned another 700 off would have them netting at only an 800 calorie intake. At that level, many people are setting their body up for a crash because it is nearly impossible to get the proper nutrition and fuel at that level.

    The less weight you have to lose, like only about 12lbs, exercise calories become more important as you have less energy reserves to pull from.

    This is an excellent summation
  • TeaBea
    TeaBea Posts: 14,517 Member
    grg243 wrote: »
    I've read a lot of posts here that you should eat back anywhere from 50-75% of workout calories. Is there a reason for this? If I've "earned" workout calories (calculated by my FitBit), isn't it better for weight loss not to eat any of those back?

    FitBits are pretty spot on for many types of exercise.....other types, not so much.

    You will need to experiment to see what fits your exercise. Besides, some people don't log food as accurately as others either. Use a percent.....then tweak as needed.
  • LadyMcClure
    LadyMcClure Posts: 42 Member
    Thanks for all of the replies. Makes a lot more sense now!
  • jeepinshawn
    jeepinshawn Posts: 642 Member
    I have been in a similar position, and trying to figure it out. I have mfp and fitbit linked, MFP says to eat 1500 calories a day, I'm on a 1,000 calorie a day deficit, and then MFP credits me with 700-900 extra calories almost everyday from my fitbit activity.

    Knowing that these are likely over estimates on my burn this week I have been ignoring what MFP says I have to eat and just making sure I stay 1000 calories below what fitbit says I have burned, which coincidentally is just about equal to the MFP 1500 plus about 30% of the extra calories MFP credits me thanks to fitbits step log.
  • Liftng4Lis
    Liftng4Lis Posts: 15,151 Member
    The winner gets to eat the most and still lose. MFP is designed to eat a portion back.
  • I have only been doing this for 12 days and have lost 4.5 lbs. I do have about 65 lbs to go so I have not been eating my exercise calories. I am interested to hear some of these replies. I am not having any trouble with keeping my calorie intake at the recommended 1700 for losing 1 lb a week so I consider these" bonus points" incase I don't accurately measure portions perfectly. I have been occasionally hungry which I expected after cutting back from around 2500 to 3000 calories a day however just logging everything in and holding myself accountable has helped me make better food choices and pushed me to start using my dormant gym membership lol. Hope I can stay this motivated