Calories in minus calories out = weight loss?

tomcornhole
tomcornhole Posts: 1,084 Member
Data are powerful. Data from the past 90 days provided for your examination.

INTAKE:

166,473 calories (1,849 cal / day avg)

OUTPUT

169,470 calories BMR (1,883 cal / day avg) This is from multiple different equations.
30,340 calories exercise (337 cal / day avg)

NET

-33,337 calories

9.52 lbs = Predicted weight loss. This should equate to 9.52 lbs of weight loss if I lost all fat. I have BodPod data at the start and finish of this 90 day period that show I maintained LBM.

16.4 lbs Actual weight loss

So, why the difference? If calories in - calories out = weight loss, why the 72% difference in predicted vs. actual? Data entry error? Maybe some, but not 72% error. I log everything (including how much I go to the bathroom). The difference in lbs lost equates to 24,080 calories. That's an average of 268 cal / day. I must be doing something to up my BMR by 267 calories. That's the only thing I can think of.

Pls discuss.

Replies

  • SideSteel
    SideSteel Posts: 11,068 Member
    Because you are continually estimating both intake and expenditure and these estimations can be off significantly.
  • CyberEd312
    CyberEd312 Posts: 3,536 Member
    Because you are continually estimating both intake and expenditure and these estimations can be off significantly.

    Yep This!!!
  • tomcornhole
    tomcornhole Posts: 1,084 Member
    Because you are continually estimating both intake and expenditure and these estimations can be off significantly.

    This hypothesis would indicate there is an approximate 14.4% error somewhere in the caloric estimations. I can believe this. And all the errors would have to err towards the weight loss side.

    I wonder if the errors are in ALL the caloric estimates or in one of the 3 primary data sets: intake, exercise or BMR? Since intake and BMR are the serious contributors, I would guess the error lies in those two numbers.

    I know that food labels can have errors in them, but they generally underestimate total calories vs. overestimate. And people tend to under report caloric intake vs. over estimate. That would indicate the estimated caloric intake would be lower than actual. And the data do not support this hypothesis. If I actually consumed more calories than my estimate, then the predicted weight loss would be even less.

    The exercise calories are such a small portion of the total that any errors there would have to be significant to contribute to the difference. And again, people tend to overestimate exercise calories vs. underestimate. If I overestimated the exercise calories, then the predicted weight loss would go down if I logged them accurately.

    That leaves us with BMR. That is a guesstimate from multiple online calculators. I think my BMR is higher than my guesstimate.
  • SideSteel
    SideSteel Posts: 11,068 Member
    Because you are continually estimating both intake and expenditure and these estimations can be off significantly.

    This hypothesis would indicate there is an approximate 14.4% error somewhere in the caloric estimations. I can believe this. And all the errors would have to err towards the weight loss side.

    I wonder if the errors are in ALL the caloric estimates or in one of the 3 primary data sets: intake, exercise or BMR? Since intake and BMR are the serious contributors, I would guess the error lies in those two numbers.

    Exercise is also an estimate. Even a heart rate monitor is using approximations to determine total energy output.

    Additionally, your maintenance intake (which is not BMR + exercise as you indicated initially. It is BMR + TEF + EAT + NEAT) is not static, it is a continually moving target.
    I know that food labels can have errors in them, but they generally underestimate total calories vs. overestimate. And people tend to under report caloric intake vs. over estimate. That would indicate the estimated caloric intake would be lower than actual. And the data do not support this hypothesis. If I actually consumed more calories than my estimate, then the predicted weight loss would be even less.

    True, but you are also assuming your loss is all tissue weight which is also a very big and likely incorrect assumption.
  • tomcornhole
    tomcornhole Posts: 1,084 Member
    Additionally, your maintenance intake (which is not BMR + exercise as you indicated initially. It is BMR + TEF + EAT + NEAT) is not static, it is a continually moving target.

    What are TEF, EAT and NEAT? Never mind. Found it:

    TDEE = BMR + TEF + NEAT + EAT

    BMR = Basal Metabolic Rate (calories burned while comatose)
    TEF = Thermal Effect of Feeding (calories burned with the process of eating macronutrient content)
    NEAT = Non-Exercise Associated Thermogenesis (unplanned exercise)
    EAT = Exercise Associated Thermogenesis (planned exercise)

    TEF is approximately 10% of your total caloric intake, which would account for an additional 180 cal / day average. NEAT is harder to nail down, but that could easily account for the missing calories. I will accept this hypothesis. Is there any accurate way to measure TDEE as it happens?


    True, but you are also assuming your loss is all tissue weight which is also a very big and likely incorrect assumption.

    What other weight can we lose other than tissue?

    BYW, I'm not asking to be a smart *kitten*. I find this fascinating.
  • SideSteel
    SideSteel Posts: 11,068 Member
    Additionally, your maintenance intake (which is not BMR + exercise as you indicated initially. It is BMR + TEF + EAT + NEAT) is not static, it is a continually moving target.

    What are TEF, EAT and NEAT?
    True, but you are also assuming your loss is all tissue weight which is also a very big and likely incorrect assumption.

    What other weight can we lose other than tissue?

    BYW, I'm not asking to be a smart *kitten*. I find this fascinating.

    TEF: Thermic effect of food.
    EAT: Exercise associated thermogenesis
    NEAT: Non Exercise Activity Thermogenesis


    Regarding the bold: Fluids. Your glycogen/water weight will decrease significantly when losing weight, especially in the beginning.
  • Robin_Bin
    Robin_Bin Posts: 1,046 Member
    Wrong "calories out"... unless you were in a coma the whole time. BMR assumes no activity. Your TDEE is energy expended.
  • tomcornhole
    tomcornhole Posts: 1,084 Member

    TEF: Thermic effect of food.
    EAT: Exercise associated thermogenesis
    NEAT: Non Exercise Activity Thermogenesis

    Regarding the bold: Fluids. Your glycogen/water weight will decrease significantly when losing weight, especially in the beginning.

    Got it. So I can conclude that predicting actual weight loss based on calories in vs. calories out is not an exact science. Fortunately, I have emperical data that suggest over the past 90 days I have lost 16.4 lbs while maintaining LBM and that makes me very happy.

    I love the science behind all this. Thank you for taking the time to explain it. I really appreciate it.
  • fluffykitsune
    fluffykitsune Posts: 236 Member
    You said yyou did podbod and all the weight you lost was fat ?
    Can we see numbers for that ? o:
  • jadams1650
    jadams1650 Posts: 139 Member
    From the OP : "I log everything (including how much I go to the bathroom)" ... and I thought I was committed.
  • darwinwoodka
    darwinwoodka Posts: 322 Member
    The Thermic Effect of Food

    Fats ratio 100:5 - For every 100 calories of fat you ingest you will burn approximately five calories in the digestive process

    Carbs ratio 100:10 - For every 100 calories from complex carbs that you ingest you will burn about ten during digestion.

    Protein ratio 100:25 - For every 100 calories you eat from protein, you will burn approximately 25 calories just to digest it.
  • tomcornhole
    tomcornhole Posts: 1,084 Member
    BodPod 21 Feb:

    201.7 lbs total weight
    157.124 lbs LBM
    44.576 lbs fat
    22.1% BF

    BodPod 8 Apr:

    188.3 lbs total weight
    156.7 lbs LBM
    31.6 lbs fat
    16.8% BF

    The 90 day window on the previous data started 10 Feb and ended today and that accounts for the 16.4 lbs weight loss. The difference in the BodPods is inside that 90 day window but covers a significant portion of the data set.
  • tomcornhole
    tomcornhole Posts: 1,084 Member
    The Thermic Effect of Food

    Fats ratio 100:5 - For every 100 calories of fat you ingest you will burn approximately five calories in the digestive process

    Carbs ratio 100:10 - For every 100 calories from complex carbs that you ingest you will burn about ten during digestion.

    Protein ratio 100:25 - For every 100 calories you eat from protein, you will burn approximately 25 calories just to digest it.

    So, a good approximation might be 10% of overall calories could be committed to TEF. For me, that might equate to an additional 187 cal / day that was unaccounted for in my data. That would only leave 80 cal / day that could easily be attributed to the fact that generally, I do not spend the day comatose. I would guess that my NEAT exceeds 80 cal/day. The scooby calculator puts my TEF+NEAT at 375 cal / day. Fascinating.
  • SideSteel
    SideSteel Posts: 11,068 Member

    TEF: Thermic effect of food.
    EAT: Exercise associated thermogenesis
    NEAT: Non Exercise Activity Thermogenesis

    Regarding the bold: Fluids. Your glycogen/water weight will decrease significantly when losing weight, especially in the beginning.

    Got it. So I can conclude that predicting actual weight loss based on calories in vs. calories out is not an exact science.

    I think that's a very reasonable conclusion.

    What you CAN do, is take an objective look at the data and your results, and make decisions about your calorie intake or calorie expenditure to attempt to adjust those results to where you want them.

    So, while it's not an exact science (at least insofar as we can measure it), we can still fine tune things to shift the results.
    Fortunately, I have emperical data that suggest over the past 90 days I have lost 16.4 lbs while maintaining LBM and that makes me very happy.

    That's the important part. Regardless of how the numbers play out, you know that you're getting great results.
  • ilovedeadlifts
    ilovedeadlifts Posts: 2,923 Member
    Because you are continually estimating both intake and expenditure and these estimations can be off significantly.

    nailed it
  • waldo56
    waldo56 Posts: 1,861 Member
    This is a very simple answer.

    The equations you used to estimate your BMR/non exercise burn are just general population estimates, in reality you personally could vary a great deal from that.

    Its great that you figured out that you do vary from the equations, and not only that you do, but how much. Now run through the calcs with 1lb = 3500 cal to figure out what your maintence level is. Whallah, now you can lose or gain at precisely the rate you expect.

    My non-exercise burn runs about 350-400 cal/day hotter than the equations expect it to. Most equations predict that I should maintain at 2400 cal/day net, but I've been doing the same math you did now for more than a year and a half, and I know that I maintain at 2750 cal/day net (it has drifted upward a bit as I've put on a bunch of muscle mass), setting calorie goals based on that number allows me to gain or lose with a high degree of precision.

    Always estimate intake and exercise expenditure the same way, try to be right, and remove the error by matching your goals with results. As long as you do it this way, you can estimate to absolutely absurd accuracy as all error should cancel out. The only way it doesn't is if you introduce bias into your estimate (estimating "safe" is an awful practice that I bet a solid 90% of people do, rule #1 in "how to not suck at estimating 101" is to not ever intruduce bias, always try to be right).
  • tomcornhole
    tomcornhole Posts: 1,084 Member
    waldo56,

    Your analysis is exactly what I was thinking. Based on my data, I think my maintenance number is 2,547 cal / day net. If I add in the exercise, my TDEE comes out to 2,931 cal / day. The scooby TDEE calculator says it should be 2,198 cal / day net and TDEE should be 2,839. Not too bad. Now that ya'll have walked me through all of this, I think I need to eat more or exercise less. I am averaging a 500 cal/day deficit and that's a 30% deficit to TDEE. But I'm losing fat and maintaining LBM, so I am hesitant to change.

    I am very careful about entering the data without bias. I want to control this process of weight loss and especially managing LBM. I hate losing muscle. It's just too hard to get back (for me anyway). This is what I have been tracking to make sure I keep my deficit and lifting balanced to maintain LBM. But now I think I am ready to increase LBM.

    LBMcombochart20130430.png

    The red dots are my BodPod data that I am using as truth data for now. LBM is steady as she goes and fat/BF% are going down.

    If everyone could track this data and make the calculations, then they would all be empowered to control their destinies. Oh, wait, all the data I used came from my MFP database. Fascinating. MFP should add a button to calculate TDEE from actual data. If you are logging your food and exercise carefully, it would spit out an actual number vs. an estimate. Remarkable.
  • waldo56
    waldo56 Posts: 1,861 Member
    I've always though MFP needs to add that capability. All the data is there to do it.
  • olDave
    olDave Posts: 557 Member
    Read the disclaimers. Not everyone's metabolism is the same.
  • joleenl
    joleenl Posts: 739 Member
    Because you are continually estimating both intake and expenditure and these estimations can be off significantly.


    ^^ this and if you just started this routine/diet at beginning of the 90 days, you could've lost water and/glycogen too.
  • tomcornhole
    tomcornhole Posts: 1,084 Member
    ^^ this and if you just started this routine/diet at beginning of the 90 days, you could've lost water and/glycogen too.

    Been cutting since March 2012. I think I have learned enough now to know what is going on with my data. I will continue to track and analyze as I always have.