Struggling to understand the concept of “water weight” and why it shouldn’t count. Shouldn’t it?

aftergodsheart

New member
To me, it seems silly to measure “weight vs water weight” or really to track down to a single pound at all. I don’t get why we should do it, or what it’s for. I hope this post doesn’t come off as judgy or rude. I genuinely don’t understand what the point of classifying water weight vs. regular weight is, and I hope someone can explain it to me.

First thing in the morning, I peed and then weighed in at X lbs.

(Sorry for the weird “X” instead of numbers. I just know people sometimes focus on the numbers in here if you list the exact number. No offense meant.)

Then I had a 421 calorie breakfast (using a food scale) and drank some water and tea and weighed myself again. Now—like an hour later—the scale was flickering between X+3 and X+4 lbs.

Yeah, it’s just “water weight,” but aren’t people 60% water or something like that? Why do the ≈3 lbs of liquid that I drank this morning not “count,” but the ≈63 lbs of water that were in my body before do? I’m going to be X+4 lbs for most of the day. For the sake of BMI and things like that, shouldn’t I count myself as X+4 lbs? I’m short enough that 4 lbs makes about 1 BMI point difference. I don’t really understand why that should be ignored. Please help!
 
@aftergodsheart For the sake of tracking changes in weight, it’s unnecessary to focus on every fluctuation you experience. Trends over time indicate change. The 3+ lbs you gain eating and drinking throughout the day mean nothing in terms of weight loss.

I gained 8lbs the other day from morning to night, but it’s not possible that was 8lbs of fat. People looking to lose weight are generally looking to lose fat, so 8lbs of water and food weight over the course of one day isn’t important or worth logging or tracking.

It’s not healthy or necessary to obsess over every fluctuation. That’s why temporary changes in water retention don’t matter.
 
@conslater Thank you for responding! Don't worry, I promise I'm not obsessing over every fluctuation—this question has just been bugging me, so I weighed myself twice in a day only so I could get numbers to ask about; it's not something I normally do.

I was wondering whether weighing yourself first thing in the morning was a matter of vanity (it's nice to see your "minimum" weight rather than your average over the course of the day) or whether it was truly a more accurate baseline of your body composition. It seems that the second one is true. I appreciate your response, especially your example of an 8lb fluctuation! Thank you.
 
@aftergodsheart When most people talk about weight loss what they're really talking about (and hoping for) is fat loss. When you lose fat, you lose it all over your body (though some people have different distributions). The extra 3-4 pounds of food and water don't distribute in the same way; your digestive tract absorbs needed macro and micro nutrients and uses them for various metabolic processes and storage. Maybe your waist will grow and inch or two from the physical food/liquid inside your stomach, but this is temporary.

This is why many recommendations for weighing yourself are: the morning, after a bowel movement, around the same time every day. Your body has absorbed the nutrients, removed the waste, and is the most accurate to your weight reflection of fat/muscle. The amount of water in your body is pretty tightly controlled as long as you're not insanely over or under-hydrated. Overall weight trends, therefore, will reflect fat/muscle loss.

Ultimately, the most important thing is weighing yourself around the same time every day in similar circumstances so you can track progression.
 
I'll also add re: water in your body, the ~60% is a mix of intracellular and extracellular and 2/3 of that is actually intracellular, so inside your cells. When you drink a nalgene of water it doesn't just immediately go into your cells, the distribution requires time and osmosis. Your body won't actually use all 2L of the nalgene; it will only use enough to maintain homeostasis (basically the balance of your body). That's part of why you pee! Our bodies take only what they need and store or eliminate the rest.
 
@aftergodsheart If you're trying to lose weight the implication is you're trying to lose fat. Water weight fluctuations are not an accurate representation of you losing fat.

I can go to bed dehydrated and wake up X lbs lighter but that isn't real weight loss. As soon as I become hydrated again my weight will go back up. I wouldn't say I gained or lost weight in that scenario.

Eating salty foods, hormones, a hard workout etc cause your body to retain water. If your goal is to lose weight (fat) and you keep seeing the scale go up or stay the same, you may become discouraged if you don't understand the impact retaining extra water can have on the scale.

That's why when people do use a scale they recommend weighing yourself in the morning and tracking often to get a better idea of actual trends (slow upwards or downwards trends you may not see as well if you just stepped on the scale each day without writing it down).
 
@aftergodsheart I think you’re over thinking it. In reality, someone’s weight is not one exact number, it’s a small range. That’s why many people recommend weighing weekly and using the average as your weight. Whether you use your base weight before food, or your weight after food, that’s still your weight.
Also, how much someone fluctuates varies between people. I personally have never fluctuated 4 pounds in a day. That type of fluctuation could mean that your body is reacting negatively to something you’re eating, or your body is hanging onto food/water for some other reason.
 
@nathanh83 Thanks for responding! Yes, I know weekly weighing is the way to go for actually tracking weight/fat loss. I just weighed myself twice today because this question has been bugging me and I wanted hard numbers to ask about in my post.

I personally have never fluctuated 4 pounds in a day. That type of fluctuation could mean that your body is reacting negatively to something you’re eating, or your body is hanging onto food/water for some other reason.

Regarding this part, I think I'm fine. My body can't make mass out of nothing. I weighed 4 lbs more right after breakfast because I put 4 lbs of stuff into it. 1 liter of water=2.2 lbs; I had soup, tea, and water, probably significantly more than a liter of liquid in total.
 
@aftergodsheart Water weight makes a difference. It shows up on the scale, and you probably have a lot of it when you feel "bloated".

But: it comes and goes easily, particularly compared to tissue loss/gain. So rather than having a single number for your body weight, it's more of a range. People tend to want a single number, though, so it's generally recommended to try and measure your weight under similar conditions every day for consistency (usually after waking and waste elimination, to minimize water weight fluctuations).

Most people "minding their weight" are really concerned about how much body tissue they have, rather than their literal weight. So the water weight just confuses the data, more than anything else.
 
@aftergodsheart You also gotta look at long term trends.

Yes when I first wake up after I pee completely naked in my bathroom is my lowest weight. That number has been going down.

If I weigh myself in the middle of the day, that number is going to be higher than my morning weight.

But my post lunch midday weight today is less than my midday post lunch weight 3 months ago.

So both weights "count". But I don't compare them to each other. They're different circumstances.

It would be like what's your max weight you can bunch press on poor sleep without eating before hand versus your max weight bench press while well rested with a pre workout snack.
 
@aftergodsheart You can get so incredibly granular with this and here’s why -

The macros you eat affect how much water your body holds onto in addition to how much food/fluid you take in over the course of the day. Eat 30g more carbs than normal one day? Your weight will increase because for every gram of glycogen your body stores, it needs 3g of water to do so. An extra 30g of carbs is roughly 180-250 cal depending on the other macros content so obviously that isn’t going to cause you to gain a lb of fat, you will burn it, but it can cause some temporary water gain.

Excess sodium can also cause weight gain too. Are you tracking every ml of sodium you consume? Heavens no, and you shouldn’t.

Hormones and menstrual cycles affect weight greatly too. Something completely out of our control.

That’s why it’s recommended to weigh in the morning when you get up because it’s the closest consistent data point you’ll be able to pull on day to day basis if you want to track weight. Weigh daily and look at your weekly averages. Do NOT look at the day to day fluctuations. If this is triggering for you then stop and consider reevaluating your relationship with the scale.

Also you mentioned BMI so I would highly recommend you do some research regarding the history of BMI and why it’s a horrible marker to use regarding what is a healthy weight.
 
@aftergodsheart Also going to chime in that water weight fluctuates not just during the day, but (at least for me), can be rather significant during my cycle. I'm at my lowest weight the day after menstrual bleeding ends; I'm at my highest 2-3 days before it begins (soooooo much bloating).

So, it's not that I've lost 6-8 pounds in a week, it's just that I'm no longer overly bloated with water weight. I know not everyone's hormones have that wide of a swing, but it does account for at least 2-3lbs in most women.
 
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