How many times have you stepped on a scale today, just to check if you're still dropping that weight? If the weight went down, it's probably time to celebrate.

Bring that donut over here!

But, is it really?

Let's look at behind the scenes...

Let's assume that someone starts a diet. They weight themselves multiple times per day, successfully sticking with the diet plan and exercise. Then a few days later the scale shows a few kilos less.

"Oh my god, that fat is just melting away!"

...BUT what happens a few weeks later, may not be that motivated anymore. The weight on your scale stopped or you might even gain a little bit of weight.

"How can this happen? "

You were 100% strict with the diet plan, you add an additional cardio session on your exercise regime...So, you decide to cut calories a bit more and more and more...until you're sitting at the dinner table eating your 3rd salad seasoned with an apple cider vinegar (no oil, cuz »fat is bad«)...while others around you are eating fish & chips. You're drained, emotionally and physically...and at some point, you give up.

This is a frequent pattern.

If weight goes down, that means it's time for celebration. But if it goes up, it's time to reduce food intake even more and add an extra hour of exercise in the gym.

This is a major problem people face when they start a diet, without appropriate guidance...

Focusing solely on the scale and obsessing over the changes becomes an enormous practical problem. Although the weighting can still be useful as long as it's approached correctly, overall these types of »short-term« changes are relatively meaningless. Especially in women.


Was it water, muscle, organs, bone, carbohydrate, fat? Or perhaps you just had a big bowel movement.

"How can a bowel movement plays a role in weight loss?"

Well, the undigested food moving from the gut through the colon before excretion can actually make up 1,5-3 kg. (1) This also largely depends on the diet (high-fiber diets tend to produce more food residue) and some other factors, like body size, water intake, bowel regularity,...

However, as you can see, this can be a significant portion of total body weight.

That said, almost without an exception, very short term changes in scale weight always represent changes in water, glycogen or food residue.

For example, someone on a low sodium-diet who eats high sodium meal may bloat up for a day or two, gaining several kilos of water weight. Chronic stress can also cause water retention. The same can be claimed for dietary carbohydrate intake.

When carbohydrates are lowered, the body tends to lose a lot of water. Many diet books are using this to their advantage as it can be very rewarding to a person.

On the other hand, it can be very frustrating when the rapid losses don't continue as the first week (Are you watching »Biggest looser« ? Perfect example.). You may lose 3 kg in the first week (or even more if you're a large individual) due to water retention and then lose only 0,5-1 kg per week after that.


That said, water, glycogen, food residue,...don't particularly count in terms of body composition. Yes, there can be minor changes with glycogen and water loss, but overall what we want to achieve is change a ratio between body fat and lean body mass. This is how body composition changes.

Lean body mass refers to everything that isn't fat ( body water, muscle mass, skin, bones, organs...)

While bodyweight can change without any changes in body fat, body weight can also stay the same while body composition is improving.

For example, if a woman starts at let's say 70 kg and 25% of body fat and 6 months later she manages to drop a body fat percentage to 20%, her weight stays the same. She may look completely different while weighing the same.

"How come?"

Firstly, muscle is denser than fat. It takes up less space than fat. And since it's denser, it weights more than fat if you compare the same size portions. What is more, muscle is also more metabolically active than fat, meaning it burns more calories when you are at rest.


Even small changes in the diet can cause scale weight to change pretty significantly in a fairly quick period of time.

However, this does not mean that bodyweight is meaningless or the scale useless. The above is a representation for "average" people to understand, that short term changes in bodyweight don't represent anything meaningful in terms of what "average joe's" are trying to lose (gain), while long term changes generally do.

Nevertheless, the scale can still have its place, especially in athletic population.

Anyhow, according to your goal, you should be focused on the changes in eighter fat or muscle mass that are occurring. If your goal is fat loss, it will be best achieved by losing fat while eighter maintaining muscle mass or even slightly increasing.

Muscle gain, on the other hand, should ideally come with as little body fat gain as possible (it's usually impossible to avoid it completely.)

That said if you're a female who is trying to improve the appearance, health,...Your main focus should be to improve your body composition, to lose fat, gain muscle or the combination of the two. Rather than scale, closing fit and mirror or pictures would be a better choice.


1. Mackenzie, M. (2019, March 09). This Is How 8 Different Weight-Loss Plans Will Impact Your Poop. Retrieved from