Weight loss , fat vs water vs muscle

jelleigh

Obviously when we are aiming to lose weight, what we are really hoping for is to lose fat. From what I understand, as the number on the scale goes down, it will inevitably include some water and muscle loss as well. Now there are things one can do to lessen the % of muscle lost like getting enough protein and following a progressive lifting/ resistance training program.

My question is are there any averages to expect? Let's assume an average person is getting enough protein and is doing resistance training ( nothing crazy intense- just normal progressive lifting), when they lose a pound, would there be an average % of water vs fat vs muscle loss?

AnnPT77

The water's a red herring, pretty much unrelated to fat and lean tissue loss.**

IIRC, I've seen estimates like 3-4 to 1 fat loss to lean loss being pretty normal, under good conditions, but I don't have a cite at my fingertips. If someone else has a good one, believe them over me.

Keep in mind that you want to lose some lean tissue: It would not be a good thing if I still had the same blood volume at roughly 2/3 my original bodyweight, y'know? And that's just one example of something that counts as lean tissue, that we need less of as a smaller person.

All you can do is what you can do: Lose at a sensibly moderate rate, get some muscle-challenging exercise, get overall good nutrition (including adequate protein, but not exclusively that), get good sleep, all that good health-promoting stuff . . . then don't stress about it, would be my suggestion. You can't do more than all you can do.

** If you haven't read this article yet, I highly recommend it:

https://physiqonomics.com/the-weird-and-highly-annoying-world-of-scale-weight-and-fluctuations

Bridgie3

muscle doesn't get lost out of proportion. your body is constantly increasing and reducing muscle dependent upon whether you need it or not. It balances the machinery required to act against the object to be acted upon.

It's just a standard efficiency. I don't think it's worth worrying about.

sijomial

Muscle loss isn't inevitable, especially if you change your lifestyle and fitness habits and start out undertrained. Clearly if nothing except your diet and weight changes a smaller body doing the same things will require less muscle.
Lean mass will decline during a significant weight loss but muscle is only a part of your total lean mass.

There must be an average but that is unlikely to be known and is of no use to an individual who can't get an accurate measure of it anyway.
Think of a 300lb very overweight person losing weight versus a lean athlete cutting a few pounds - their results are going to be very different. That 300lb person's results will change as they get closer to goal weight.

PAV8888

In a two compartment model, Lean mass = everything that is not fat, and fat mass = fat.

Bio-impedance scales at best differentiate between fat and non fat. The rest comes from an average model, possibly a more "personalized" model using information you've already given about age, sex, height, and weight. Which are not THAT personal.

You lose both fat and non fat mass. A 300lb person loosing weight and increasing activity could have "most excellent" results losing 10:1 fat to lean mass (ask me how I know ) But become a 170lb person and the results may be closer to 1:1 (I wonder whether there were some DEXA scans involved in this... )

Various weight loss studies with various conditions have variously listed weight loss results ranging from 6+:1 to 0.5:1
As Ann mentioned: 3:1 is a pretty common result if sufficient fat is available to be lost. Going from memory, 2:1 was not unknown. 3:1 would correspond to 75% - 25% which is a fairly common split.

And all this doesn't matter.

You can't control age or sex. You CAN control your decision to lose weight based on your currently available fat to be lost; but let's take that as an external decision.

Once the decision to lose has been made, all you can control to tilt things in your favor is rate of loss, protein consumption, type and amount of exercise, and amount of sleep.

Not surprisingly, assuming it has enough resources, your body will prioritize what it needs.