Weight fluctuation in day

Silentpadna

VintageFeline wrote: »

I honestly don't know what point you're trying to make. It just seems like arguing for arguing's sake.

It's not even meant to be an argument per se. As not just a numbers guy, but a math guy too, I'm not convinced that time of day matters as much as many think it does. That's the point. I see the recommendations to weigh yourself under the "same conditions", but don't see the logic in it for reasons I've tried to explain. I do understand the idea of doing that, but I believe the math is more complicated because of the number of variables involved. And because time is a monumentally bigger factor (all things equal), trying to make the conditions consistent or the same is not possible.

Tacklewasher

Silentpadna wrote: »

VintageFeline wrote: »

I honestly don't know what point you're trying to make. It just seems like arguing for arguing's sake.

It's not even meant to be an argument per se. As not just a numbers guy, but a math guy too, I'm not convinced that time of day matters as much as many think it does. That's the point. I see the recommendations to weigh yourself under the "same conditions", but don't see the logic in it for reasons I've tried to explain. I do understand the idea of doing that, but I believe the math is more complicated because of the number of variables involved. And because time is a monumentally bigger factor (all things equal), trying to make the conditions consistent or the same is not possible.

More consistent, less variables. Please don't make it black and white. It is better to improve the consistency as much as reasonably possible. If I can have a 5 lb fluctuation during the day, but can eliminate that from the data collection, that is preferable.

It's not perfect, it is better.

CSARdiver

First thing in the morning after you void.

My weight fluctuates ~5 lbs throughout the day on the average. Changes in diet, especially sodium intake, will cause your body to retain water temporarily.

stanmann571

Silentpadna wrote: »

stanmann571 wrote: »

IF you weigh less often, you become more vulnerable to noise.

The more data points you gather, the smoother becomes the curve of your data.

Why is that? Doesn't it depend on the window of time you are taking data? What if you took 20 data points over a one week stretch, and I took 4 over an 8 week stretch. Which do you think would give you the most accurate trend? The one with more data points or the one with more time? Further, If I took 4 over an 8 week stretch and you took 40, would our trend lines be substantially different?

What is the smoothest curve? Either a linear function (no curve), or a perfectly functional curve where the the dependent variable (weight in this case) is precisely related to the independent variable (time). We know it's not, because weight itself is comprised of more than one thing and they change at different weights due to totally different circumstances. As a result, we end up with a trend line (or curve) that can be calculated using data points. If our goal is to lose fat we need a long time window to see the trend line because fat weight changes slowly.

Look at the data for stock prices or market indexes. Over the very long term the curve is much more smooth than shorter terms. Why? Because daily, weekly, or monthly fluctuations vary much more dramatically than long-term ones. If you are looking for what will happen to a stock price or index over a very long period of times, it doesn't matter at all what time of day you check its price on a given day. It's not a perfect mirror for weight fat loss, but it does illustrate that the more data points there are, the more noise there is. But...the number of data points don't affect the trend...they are simply components of it.

Here you go.

Representative data from my past months weigh ins. I've gained 2-3 lbs

However, had I only weighed 3 times I might believe that I'd lost 4 lbs.

1 237, 232, 235
2 234, 236, 235
3 233, 237, 234
4 234, 236, 236
5 233, 238, 235
6 234, 233, 237
...
15 235, 236, 237
...
31 233, 239, 237


And yes those are actual numbers from the past month. Not all of them.

In response to your stock market comment. the number that counts is the EOD number(which is actually the market close number) for the same reasons as weight first thing after voiding in the morning. It is the number least subject to manipulation by non-substantive factors.

I really can't figure out why you're pushing so hard since you claim to not even hold to the position you're defending.

CSARdiver

Silentpadna wrote: »

VintageFeline wrote: »

I honestly don't know what point you're trying to make. It just seems like arguing for arguing's sake.

It's not even meant to be an argument per se. As not just a numbers guy, but a math guy too, I'm not convinced that time of day matters as much as many think it does. That's the point. I see the recommendations to weigh yourself under the "same conditions", but don't see the logic in it for reasons I've tried to explain. I do understand the idea of doing that, but I believe the math is more complicated because of the number of variables involved. And because time is a monumentally bigger factor (all things equal), trying to make the conditions consistent or the same is not possible.

I believe I understand the point you are attempting to make, but you are at odds with the inherent messy behavior of biological systems and attempting to apply a clean mathematical approach, which is by nature abstract.

The rationale behind weighing first thing in the morning is a population generalization removal of variables. Water and glycogen weight being the primaries. After evening rest your body goes into a critical dumping phase and removes toxins - which is also the rational behind the medical importance of testing your first morning urine - this presents a worst case scenario.

Any scientist would want to eliminate as many variables as possible in any measurement, especially in the practice of weight management where the focus is reduction of fat loss.

This has the same purpose of taring a scale before weighing or sealing the scale within a physical barrier to minimize impact of air flow.

Silentpadna

Tacklewasher wrote: »

More consistent, less variables. Please don't make it black and white. It is better to improve the consistency as much as reasonably possible. If I can have a 5 lb fluctuation during the day, but can eliminate that from the data collection, that is preferable.

It's not perfect, it is better.

I understand the idea. But why is it better?

Whatever time you weigh yourself is cool. I'm not arguing that or debating that, and I'm especially not saying it's bad. What I am saying is that it doesn't matter much. Your own example shows a fluctuation of 2.5x (in a day) the amount of weight loss you would achieve in a week if you were aggressive, 10x if you are going slow. That means in order to minimize noise, you need time. Once you have enough time, the individual data points don't matter. Wherever you are in the 5 lb cycle of fluctuation throughout your day is irrelevant to your fat loss. Not only that, our digestive tracks move at different speeds for different people. Same with diet and workout type. All the different things that speed up or slow down fluid retention make it impossible to have a consistent baseline to work from in the first place.

Whether you eliminate it or not from the data collection is irrelevant. For example, I weigh 219 lbs right now. In 20 weeks I would like to weigh 189 or thereabouts, maybe less if I can, but I think I'll be slowing down my goal speed a little before that. Assuming I reach that goal, however many data points I get between now and then and when those data points occur is irrelevant.

Again, I am not saying weighing at a particular time is a bad idea. It's a fine idea. But because of the complexity of body processes, the magnitude of daily (and even hourly) fluctuations, the consistency seems to me to be a myth, even if it seems intuitively correct.

Silentpadna

CSARdiver wrote: »

I believe I understand the point you are attempting to make, but you are at odds with the inherent messy behavior of biological systems and attempting to apply a clean mathematical approach, which is by nature abstract.

The rationale behind weighing first thing in the morning is a population generalization removal of variables. Water and glycogen weight being the primaries. After evening rest your body goes into a critical dumping phase and removes toxins - which is also the rational behind the medical importance of testing your first morning urine - this presents a worst case scenario.

Any scientist would want to eliminate as many variables as possible in any measurement, especially in the practice of weight management where the focus is reduction of fat loss.

This has the same purpose of taring a scale before weighing or sealing the scale within a physical barrier to minimize impact of air flow.

This is a great response - and partly why I brought up the subject. I've learned something with that and it helps. I don't know that the magnitude makes a dent in the long-term window of fat loss over time, again because substantial loss should make those factors small. But I do get in the shorter term why this might have impact. Your response gets one the "Awesome" votes from me.

Again, I'm not trying to be argumentative - I like to challenge ideas that seem like they are intuitive, but may not be. Thanks for your response.