Daily Weight Fluctuations Experiment

Daily weight fluctuations experiment || Do you know how much your weight can change, just in the course of a single day? || Click through to read more, or repin to save for later!

When you’re trying to lose weight, it’s pretty normal to, well, weigh yourself. Weight loss, however, is for most people about losing fat, not muscle, water, bones, organs, sanity or limbs.

But how does the scale know the difference between what’s fat and what’s not?

Truth is, it doesn’t.

This post is part of a 3-post series about weight fluctuations:

  1. Daily Weight Fluctuations Experiment
  2. What Causes Daily Weight Fluctuations?
  3. 12 Tips for a Better Weigh-In

If you weigh yourself often, you can easily get caught up in small fluctuations and forget the bigger picture. It’s easy to get discouraged if you seem to have gained a couple of pounds compared to last time – but a small weight gain over a short period doesn’t always mean you’re not making progress. To give you an idea of how much your weight can fluctuate throughout the day, I turned myself into a guinea pig poof – and weighed myself multiple times throughout a normal day.

I tried to weigh myself as many times as possible throughout a day. This is just from a normal Monday (rest day) for me. This is what the scale told me:

Weight fluctuation

As you can see, my weight fluctuated quite a bit!

Let’s break it down:

  1. 57.7 kg: Morning weigh-in. Right after waking up and going to the toilet – before eating or doing anything else.
  2. 58.4 kg: My weight increased right after I had finished my breakfast.
  3. 58.1 kg: As time went by, my weight started doing down again.
  4. 58 kg-58.5 kg: What? My weight suddenly increased with 0.5kg in a matter of minutes – I’ll show you why later!
  5. 58 kg: My weight is back down. Explanation will follow 🙂
  6. 58.4 kg: Weighed in about an hour after lunch – number would probably have been high if I had done it right after
  7. 59 kg: Again, I didn’t weigh in right after I had dinner (2 hours later to be exact)
  8. This one isn’t in the graph, but just so you know, my weight was back to normal (57.6 kg/127 lbs) when I weighed in the morning after

I’ll go more into the factors that causes you weight to fluctuate this much in a later post (it’s not uncommon to fluctuate even more throughout the day). Now, let me explain what the little water experiment was about.


It can actually be explained very simply: I weighed myself before and right after drinking a bottle of water (0.5 L /16.9 oz).

Water experiment. My weight before and after drinking 0.5 L=0.5 kg water. Sorry you have to look at my feet

It’s not surprising, but so important to remember if you’ve ever felt bad about what the scale tells you. Your weight fluctuates all the time. You put stuff in it, and stuff comes out again – when you go to the toilet, and because your body uses most of what you put into it as fuel.

You need energy to:

  • Maintain your body temperature,
  • Keep your organs working
  • Keep your muscles moving

Just like when you throw stuff in a fire: it gets reduced or ‘disappears’, because it gets turned into energy. For a fire, the energy is in the form of heat, but in your body it is chemical energy. This is used for a variety of important processes. Your body is like a fire, just much more complicated and less hot. Who am I kidding, you’re a hot sexy beast.

Drinking water will make you gain weight temporarilybut you’ll pee it out again later! To make the chart over how my weight fluctuated throughout the day, I could have plotted in when I went to the toilet – but I thought that would be way too much information, so I spared you from that 🙂

Why do you (not) weigh yourself? Have you ever noticed how your weight changes during the day? Let me know in the comments below!

Gif that says lots of love, Anne xx

Since you made it to the end, you may as well follow me on Instagram – but their algorithm is a bit of a mystery, so you can sign up to the newsletter to not miss out on the best posts! ✨

Daily Weight Fluctuations Experiment
Join the Conversation


Leave a comment

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.

  1. says: Penelope Smith

    I want to get a good scale for my bathroom soon. So, I like that you pointed out that I can have water weight. That does seem like something I would forget about. After all, it would be smart for me to know when I am using a scale.

  2. It’s really interesting to see this actually plotted out! I’ve weighed myself a few times in a day before just to see how my weight fluctuated, but I never tracked it. It really gets to me when people weigh themselves constantly and are moaning about putting a couple of lbs on in a matter of hours or days. As you’ve shown, weight fluctuates naturally! Makes sense when you think that food and drink also weighs something, and whatever you put in or on you makes a difference haha!

    1. says: Anne

      Thanks Katie! Exactly – I never know what to tell people when they’re proud of losing 1-2 lbs – I mean, I’m proud of them for making an effort, but it’s really not the best way to measure progress.

  3. says: Nadia

    Great post and love the break down and the chart! 🙂 I love things like that way too much, hon lol.
    It’s actually good observation and fun to see those changes. I had a stage when I was weighing myself not only every day but a number of times during the day. I actually haven’t stepped on the scale for quite a while now. But I do feel like my body is missing exercise and I have been eating too much junk over the holidays (who hasn’t). So I will be pushing myself to start working out. I will also be keeping up with your blog and definitely will appreciate any fitness (and healthy diet) related articles and tips in the future, hon 🙂
    xox Nadia

    1. says: Anne

      Thank you Nadia! Haha I love everything that can be plotted into a neat graph. You’re definitely not the only one who feels that way – it’s just a yearly routine! I already have a few things in mind, hopefully it won’t take me too long to finish them.

  4. Of course, I noticed it! It’s common sense really, you put food that weights in your stomach and it adds to the weight you have. Then after it digests, the weight of that food or drink disappears. In other words, you pop or pee it out! If I want to know my real weight I always step on to those scales first thing in the morning 🙂
    But this is a great post for those who need a little bit of guiding to understand it 🙂

    -Leta | The Nerdy Me

  5. Hi Anne,
    Great post!
    When I was in my early twenties I was getting ready for a swim class and weighed myself. While I was in great shape, and didn’t realize it :/ the one to three pounds “extra” shown on the scale had such a negative impact. I stopped weighing myself for quite sometime. I really had no reason to.

    Now I have a better relationship with the scale. I only weigh myself first thing in the morning, in by birthday suit ;), only do it, if I know I’m ready for the number, and if I’ve been feeling not ready, that tells me a lot.

    When I know I don’t want to see, I get into action, especially if my pants are getting snug. I focus on proper living and then get on the scale.

    The graph is very helpful. I’ll probably share this post.

    Have a great week!

    1. says: Anne

      Hi Yvette! I’m really glad you found your way to a healthier relationship with the scale – I’m hoping this will encourage someone who’s not yet there to realize that +- a few pounds doesn’t mean anything. Thank you xx

    1. says: Priscilla

      Great post. I just had a lot of water post workout and instantly regretted stepping on the scale 😑 glad that this is temporary and a 1-2kg fluctuation is no biggie