Water Weight VS Body Fat: 9 Reasons That Explain The Daily Scale Fluctuations

Let me ask you, have you ever stepped on the scale and saw it go up, let’s say two pounds, three pounds, and you started stressing that it was what you ate the day before that caused this weight gain?

Water Weight Poll

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If you did, please leave a comment and let me know, then read the article, and write what you think actually happened.

Differentiating between losing body water and losing body fat.

Let’s discuss water fluctuations and what the differences between losing water weight versus losing weight mostly from fat are.

What you care about when you’re trying to lose weight is that you become smaller, right? You want to trim all the fat so that you lose dress sizes and that will happen when you lose fat, but it will not happen if you’re losing water weight.

(For the purpose of this article, I need to clarify that when we talk about losing fat, we’re oversimplifying. We’re not just losing fat (adipose tissue), unfortunately; some muscle mass will also be lost. That’s why things like exercise and eating protein can help in slowing down the muscle loss and losing more fat instead.)

Can you really gain 2 lbs of fat in a day?

Let’s say that you have a normal weight of around 200 pounds, and then tomorrow you’re 202 pounds, that’s what the scale says. Now, let’s also assume that your maintenance calories are around two thousand calories a day (want to know your maintenance calories? Use our calorie calculator.)

What that 2000 number means is that you need to consume around two thousand calories on a daily basis for you to neither gain weight nor lose weight, that is what maintenance is.

One pound of fat is roughly equivalent to three and a half thousand calories. So two pounds of fat would mean a calorie surplus of 7000. That means that on top of your regular maintenance calories, you will need to have a calorie surplus of seven thousand calories.

In a single day you would have to consume nine thousand calories to actually walk on the scale the next day and see two pounds up, and these two pounds to be attributed to you gaining fat!

A calorie intake of 9000 for a two thousand calorie person is more than four days worth of food!

Did you eat four days worth of food? I doubt it. This is a very clear sign that you have water fluctuations.

Can you really lose 2 lbs of fat in a day?

Let’s say today you are the two hundred pound person with the 2000 daily maintenance calories and you went on a diet and the next day you weigh yourself and you’re two pounds down.

You’re like “Success! I lost two pounds in my first day of dieting!”

Did you really lose two pounds of fat? No, it’s virtually impossible because even if you were to eat nothing, zero calories, that would bring you to a two thousand calorie deficit.

(Please don’t go ahead and eat nothing!)

Since one pound of fat is roughly equivalent to 3500 calories, in order for you to lose that, you need to eat three and a half thousand calories less than maintenance. OK, so even if you were to eat nothing, that’s two thousand calories less. So you’re way less than the three and a half thousand mark for one pound, let alone the seven thousand calories that you would need to actually lose two pounds of fat.

There’s something else going on and that has to do with your water weight.

What is Water Weight And The 9 Factors That Explain Daily Scale Weight Flucuations?

Some people might see great fluctuations on the scale, they might see four pounds up, then three pounds down the following day, while some others will not see that big fluctuations or not as often.

Let’s discuss what affects those daily scale weight fluctuations.

1. Body Composition: Muscle mass vs body fat percentage

Your water weight has a lot to do with how muscular you are. So body composition plays a big role. What that means is that the more muscle you have actually, the higher the chances that you will see higher fluctuations on your scale weight.

2. Age

The younger you are, the higher the fluctuations you’re going to get. Why? Because you have more muscle.

So if you’re a young adult, you’re way more likely to see those water fluctuations versus if you’re a 90 year old adult who suffers from sarcopenia.

3. Sex

The next factor is gender. Because of body composition, men have about 60% of their weight come from water weight. While, for women that is 50-55% water percentage. That again has a lot to do with higher muscle mass in men.

4. Intense Exercise

The next factor is high intensity training and endurance training. So if one day you do a lot of exercise and that’s a very intense exercise, or if you’re doing strenuous endurance exercise, so you exercise for a prolonged period of time, that will directly go and tap into your glycogen stores.

So what is glycogen? When your body consumes carbohydrates, these turn into glucose in your blodd. And then if your body does not need all the glucose it is getting straight away, then it’s going to take glucose and store it mostly in your liver and in your muscles in the form of glycogen.

Now here’s what’s interesting about glycogen: For every one gram of glycogen, you’re going to be storing it together with three grams of water.

So the moment your body taps into those carbohydrates, stored carbohydrates that are in your muscles and in your liver and also in other parts of your body, for every one gram that the body’s using, you’re also getting rid of three grams of water.

You will see an immediate change in your weight because of that. So high intensity training and also prolonged exercise directly tap into those stored carbohydrates for energy.

5. Starting a low carb or keto diet

keto snacks smoothie bowl

Another factor that causes scale weight fluctuations is your consumption of carbohydrates. So if today you start a low carb diet, a really low carb diet, guess what your body is going to do?

It likes those carbs so it’s going to tap into those glycogen stores straight away. Again for every one gram of glycogen, you are going to be also getting rid of three grams of water.

So you’re going to see an immediate dip in your weight that is not fat loss. It’s water weight loss. That’s all. That’s all there is. Once those glycogen stores start getting depleted,

We have around 500 – 600 grams of glycogen stored in our body. And because for every one gram of glycogen we have three grams of water that means that we have three times multiplied by 600, another 1800 grams of water.

So in total we have 2400 grams of glycogen that’s stored together with water. So the moment you start tapping into this glycogen, you also tap into the water, you’re going to see, let’s say, very easily three pounds of weight. Then once you start depleting those stores, weight loss is going to slow down.

Then the scale will start reflecting more about what’s really going on with your fat loss rather than your weight loss in general, because the scale does not just measure the weight of your fat.

And if this is you do not think this is a “weight loss plateau.” You’re not a plateau, you’re simply done with the rapid water weight loss phase and more accurately seeing what’s going on with fat loss.

6. Reintroducing carbs after a low carb diet

Let’s say you have been on low carb diet and you’ve been doing that for a while and now you’re like, “I’m going to have this risotto, I’m going to have carbs, I’m going to have a lot of carbs!”

Now, the moment you start reintroducing carbs, your body’s like, “yeah, I’m going to use them and store any leftovers as glycogen” for every one gram of carbohydrates, boom, another three grams of water. And then the next day you’re going to weigh yourself.

“Oh no, I had this one meal, I had this risotto, I gained two pounds!!!” No! You didn’t gain two pounds of fat. We discussed that earlier on, in order to gain two pounds of fat, remember what we were just talking about in our example with eating more than four days worth of food in a single day? Yeah, that didn’t happen. This is just water being replenished in your body.

7. Sodium Intake

Now, the next factor is how much salt you’re consuming in your diet. If you’re consuming a lot of salt, salt tends to cause water retention. The advice is to eat less than 2300 mg milligrams of sodium on a daily basis. And what is also going to help is to consume an adequate amount of potassium. Okay, so think of potassium as the opposite of salt. (Eat your bananas!)

Sodium is just one way your body can increase fluid retention. In fact, multiple factors can make your body retain water (remember that last time you went on a plane?)

8. Getting sore (DOMS)

The next factor that most people do not always think about is getting sore. OK, so you go do some exercise and then you’re very sore, “ugh, I can’t walk, I can’t walk, can’t walk!”

Well, what happens, especially when you’re getting sore is, there’s these there are micro injuries in your muscles, OK? And that is actually what makes your muscles grow.

And you don’t have to be sore to experience that. But inflammation will increase the water content, so that might affect the result you see on the scale.

So working out affects the water in your body in multiple ways:

  • using glycogen especially through high intensity training and endurance exercise
  • sweat, which I didn’t mention before. The more you sweat, the lower your water content.
  • soreness

So if you are doing exercise, exercise is generally affecting your with your water weight.

9. Inconsistent weigh ins

And finally, the last factor is you weigh yourself sometimes in the morning and sometimes at night. If you’re doing it first thing in the morning, you’re more dehydrated than what was going on the night before. So pick a time, ideally first thing in the morning and stick to that.

To sum up, if you’re seeing two pounds, three pounds, four pounds, five pounds in a single day, that is not losing fat.

Was the scale up two, three, four, five pounds today? Here's how to explain the daily scale fluctuations and how to know if you're truly losing weight. | Lose Weight | Weight Loss | Weight Loss Tips | Weight Loss Facts

OK, most people, when they’re losing fat, they’re losing an on average of 0.15 pounds on a daily basis. Now for you to see this 0.15 lbs loss on the scale, you need to accumulate a lot of days of being of losing fat because the scale is not sensitive enough to pick up on this small amount of fat loss on a daily basis.

And at the same time, because the scale also measures not just the weight of your fat, but the total body weight: your muscle mass, bone mass, weight of your organs, etc. That’s why it’s very difficult to differentiate fat loss from everything else is going on your body and why you need a lot of days on a calorie deficit to see that fat loss on scale.

When will fat loss show up on the scale?

So with my clients, I tell them, listen, what are you doing today and every day, you will maybe see it show up on the scale two weeks from now. In the meantime, the scale is going to do its own thing, but within two weeks you should start to see the daily numbers to change in a meaningful manner.

So do not think that the things you eat today or don’t eat today, are responsible for fat loss that you think you see on what the scale says on the next day.

Again, we don’t care about water weight because water weight, like I said before, will not drop your dress sizes. That’s why I advise my clients to not just weigh themselves, but to also take their measurements. Simple tests lke the “Jeans Test” will say a lot aout your fat loss.

The tricky part? It take a few weeks to see those meaningful results on the tape and with the Jeans Test. Stay patient, it takes a while to see those abs!

So, now that you’re done with the article, why do you think you get fluctuations? Leave a comment and let me know.

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