Weight loss is not linear; Is fat loss?

AnswerzPwease

im going to say no

as you get closer to you goal weight, you need to decrease your deficit in order to prevent muscle loss, so in that case you are losing less fat than before changing your deficit obviously

if you dont lower your deficit, you will begin to lose more muscle, so again in this case the loss wouldn't be linear

Linear under constant conditions.

there are no constant conditions if you are losing weight though. do you mean constant calorie intake? that would be the second situation i mentioned

I think he means a constant % of defecit.

For example, 20% defecit of TDEE at all times.

well since TDEE decreases as you lose weight, your deficit would also decrease, therefore you would be losing less fat no?

Oh I get what youre saying now.

DeguelloTex

im going to say no

as you get closer to you goal weight, you need to decrease your deficit in order to prevent muscle loss, so in that case you are losing less fat than before changing your deficit obviously

if you dont lower your deficit, you will begin to lose more muscle, so again in this case the loss wouldn't be linear

Linear under constant conditions.

there are no constant conditions if you are losing weight though. do you mean constant calorie intake? that would be the second situation i mentioned

I think he means a constant % of defecit.

For example, 20% defecit of TDEE at all times.

well since TDEE decreases as you lose weight, your deficit would also decrease, therefore you would be losing less fat no?

My goal deficit per day is 1000 calories in MFP. It has been 1000 since I started. Whenever I hit a new low weight, I have MFP recalculate my calorie goal for two pounds per week. How is that not constant, given the limitations of being a human being and not a computer simulation?

if your goal deficit has always been 1000 and you are losing weight then your % deficit is not constant. your tdee isnt constant since you are losing weight, so the ratio of fat to muscle loss will decrease as you move along

I never claimed my deficit percentage was constant. I never claimed my TDEE was constant.

If my deficit is, as near as can figured, 1000 calories a day and 7000 a week, why wouldn't fat loss be very, very close to a constant two pounds a week? I get that this can be hidden by other factors but, presuming for the sake of argument that the information I've presented is true and accurate, why wouldn't "true"fat loss be very nearly linear? And, if it isn't, other than measurement problems at the margin, why not? Other than an undetected slowing of metabolism, how could CICO be squared with not losing mass (fat or muscle) even if fluctuations mask the loss in the short term?

ETA: A true 1000 calorie a day deficit along with counting two-thirds of my exercise calories (to account for inflated burn numbers) would result in a loss of about 3.5 pounds a week. My average weekly loss as of this morning is 3.48 pounds.

BigT555

I never claimed my deficit percentage was constant. I never claimed my TDEE was constant.

If my deficit is, as near as can figured, 1000 calories a day and 7000 a week, why wouldn't fat loss be very, very close to a constant two pounds a week? I get that this can be hidden by other factors but, presuming for the sake of argument that the information I've presented is true and accurate, why wouldn't "true"fat loss be very nearly linear? And, if it isn't, other than measurement problems at the margin, why not? Other than an undetected slowing of metabolism, how could CICO be squared with not losing mass (fat or muscle) even if fluctuations mask the loss in the short term?

ETA: A true 1000 calorie a day deficit along with counting two-thirds of my exercise calories (to account for inflated burn numbers) would result in a loss of about 3.5 pounds a week. My average weekly loss as of this morning is 3.48 pounds.

you asked what wasnt constant thats why i said your tdee and % deficit wasnt constant
we are talking linear fat loss here, not linear weight loss. you are in the second situation that i mentioned, where as you get closer to your goal weight you are keeping your deficit constant, so the ratio of fat to muscle lost is decreasing, therefore the fat loss is not linear, even if weight loss is

DeguelloTex

I never claimed my deficit percentage was constant. I never claimed my TDEE was constant.

If my deficit is, as near as can figured, 1000 calories a day and 7000 a week, why wouldn't fat loss be very, very close to a constant two pounds a week? I get that this can be hidden by other factors but, presuming for the sake of argument that the information I've presented is true and accurate, why wouldn't "true"fat loss be very nearly linear? And, if it isn't, other than measurement problems at the margin, why not? Other than an undetected slowing of metabolism, how could CICO be squared with not losing mass (fat or muscle) even if fluctuations mask the loss in the short term?

ETA: A true 1000 calorie a day deficit along with counting two-thirds of my exercise calories (to account for inflated burn numbers) would result in a loss of about 3.5 pounds a week. My average weekly loss as of this morning is 3.48 pounds.

you asked what wasnt constant thats why i said your tdee and % deficit wasnt constant
we are talking linear fat loss here, not linear weight loss. you are in the second situation that i mentioned, where as you get closer to your goal weight you are keeping your deficit constant, so the ratio of fat to muscle lost is decreasing, therefore the fat loss is not linear, even if weight loss is

I'm 74 pounds from my goal weight. I'm not sure how much that ratio has changed at this point.

I don't think I asked what wasn't constant. I think I asked why a 1000 calorie deficit across time isn't considered constant.

AnswerzPwease

Just curious.

Weight loss I presume is not linear due to the body holding water, etc.

However, thermodynamics dictates that if you burn more energy than you consume you should constantly be using your fat stores to sustain. Correct? Therefore, even though the scale is not linear, fat loss should be, right?

I like this weightloss simulator. It gives a visual of the blips that happen to everyone when they make "lifestyle" changes to their diet and exercise. The link to the simulator is towards the middle, and you may need to allow popups and java to run, if you turn those things off. Maybe this will help you visualize the theories about what's happening to your body.

WARNING, there's lots of info you have to put in so it's making it's estimate for you (like putting in your body fat% and activity level and other stuff -- everything in the green boxes). You'll note that it has a body fat% tab to see the change over time to body fat %. Of course, this is just a simulator, and you can turn on the "weight range" option to see the error rate lines.

You know... if you're the kind of person that clicks on links on the internet.

http://www.niddk.nih.gov/research-funding/at-niddk/labs-branches/LBM/integrative-physiology-section/body-weight-simulator/Pages/body-weight-simulator.aspx

That simulator is amazing! That should be a stickie haha

I'm a little upset at realizing how much longer its going to be though lol

hmaddpear

In the real world, no. Too many uncontrollable factors are at play for it to work perfectly. You've got three main energy sources - your food intake (estimated), your fat reserves and your lean body mass. As the switch between the last two is not under direct control of the dieter, then loss of your fat reserves cannot be 'linear'. Add to that only estimated burns, NEAT, BMR and intake and it's a wonder we can guess at all what a given drop in a week could be!

In an ideal world, it would be, of course. But our bodies are not big black boxes, as much as we'd (possibly) like them to be!

BigT555

I never claimed my deficit percentage was constant. I never claimed my TDEE was constant.

If my deficit is, as near as can figured, 1000 calories a day and 7000 a week, why wouldn't fat loss be very, very close to a constant two pounds a week? I get that this can be hidden by other factors but, presuming for the sake of argument that the information I've presented is true and accurate, why wouldn't "true"fat loss be very nearly linear? And, if it isn't, other than measurement problems at the margin, why not? Other than an undetected slowing of metabolism, how could CICO be squared with not losing mass (fat or muscle) even if fluctuations mask the loss in the short term?

ETA: A true 1000 calorie a day deficit along with counting two-thirds of my exercise calories (to account for inflated burn numbers) would result in a loss of about 3.5 pounds a week. My average weekly loss as of this morning is 3.48 pounds.

you asked what wasnt constant thats why i said your tdee and % deficit wasnt constant
we are talking linear fat loss here, not linear weight loss. you are in the second situation that i mentioned, where as you get closer to your goal weight you are keeping your deficit constant, so the ratio of fat to muscle lost is decreasing, therefore the fat loss is not linear, even if weight loss is

I'm 74 pounds from my goal weight. I'm not sure how much that ratio has changed at this point.

I don't think I asked what wasn't constant. I think I asked why a 1000 calorie deficit across time isn't considered constant.

you're right, the change at this point will be very minimal, but its there, and will become more apparent as you get closer to your goal weight

my mistake on the constant question, i misinterpreted what you were saying. but still I wouldnt consider your deficit exactly constant because relative to your tdee its actually increasing

WaterBunnie

We don't only lose fat or muscle, a lot of what we lose is also water as we drop so who knows what a 2lb loss actually comprises of!

WBB55

Just curious.

Weight loss I presume is not linear due to the body holding water, etc.

However, thermodynamics dictates that if you burn more energy than you consume you should constantly be using your fat stores to sustain. Correct? Therefore, even though the scale is not linear, fat loss should be, right?

I like this weightloss simulator. It gives a visual of the blips that happen to everyone when they make "lifestyle" changes to their diet and exercise. The link to the simulator is towards the middle, and you may need to allow popups and java to run, if you turn those things off. Maybe this will help you visualize the theories about what's happening to your body.

WARNING, there's lots of info you have to put in so it's making it's estimate for you (like putting in your body fat% and activity level and other stuff -- everything in the green boxes). You'll note that it has a body fat% tab to see the change over time to body fat %. Of course, this is just a simulator, and you can turn on the "weight range" option to see the error rate lines.

You know... if you're the kind of person that clicks on links on the internet.

http://www.niddk.nih.gov/research-funding/at-niddk/labs-branches/LBM/integrative-physiology-section/body-weight-simulator/Pages/body-weight-simulator.aspx

That simulator is amazing! That should be a stickie haha

I'm a little upset at realizing how much longer its going to be though lol

But I hope it gives you a realistic vision of what changes you make are likely to do, according to their simulation. Try to not think of how long it's gonna take. It took me two years to lose 100 lbs (I've added muscle since then for performance). At the beginning, it's less about the exact numbers you use, and more about just adherence to a plan of some kind. It has to be food and exercise you'll actually do on a regular basis.

Read the sexypants post again. I know you're enthused and impatient. And that's awesome. You're learning a lot and learning what works for you. You're GONNA be frustrated. You're GONNA be impatient. That's ok. Just come back and post what's up. We'll help you thru it.

lindsey1979

I've seen nothing in scientific literature one way or the other, but my guess is that it's not linear. There are simply too many unknown factors. Efficiency comes into play and that shifts. Same with hormones, which are one of, if not the biggest, factor in efficiency of fat loss.

There was a recent study that showed that when subjects lost more than 10% of their body weight, their leptin levels were disproportionately lower and their muscle efficiency was higher (i.e. burned less calories than expected for activities at their new body weight). For some, their BMR was up to 20% less than what would be expected given their new body weight. And, these are only two of the various issues -- there plenty of other hormones that could affect this.

I think that's one of the big reasons people recommend smaller deficits and slower weight loss as you get closer to your ideal body weight/composition -- because these very things do shift. I don't think there are any constant conditions that could provide for linear fat loss.

You have to remember that from a survival perspective, the body wants to hold on to fat to some degree -- that's what got it through the famine times in the past. We didn't evolve in an environment of plentiful, constant good food supply -- that's a fairly modern change.

Aaron_K123

Honestly the two times in my life I have intentionally lost weight via calorie counting my weight loss has been extremely linear. Not sure if I am a special snowflake or if I am just trained on how to take reproducible measurements or what but yeah, pretty much an exactly straight line with low error in the measurements (+/- 1 pound).

You can see my weight over time for the last three months in a graph on my profile and it has been solidly predictable.