Why does my weight go up and down so much? 7 main causes of weight fluctuation.

Does your weight bounce around by 4-5 pounds per day? Do you weigh one thing in the morning, and then, gasp, something else entirely by bedtime, no matter how careful you are during the day? Has trying to understand this up and down weight gain and loss driven you a bit nuts?  Yeah, us too. 

The truth about daily weight swings, is that most of the time, it’s just your body doing it’s thing. Don’t panic or let it drive you crazy, it turns out that it’s totally normal for your weight to fluctuate. Our bodies are constantly in the process of keeping us alive, and those bodily functions involve mixing, exchanging and releasing liquids and substances that cause our daily weight to yo-yo. 

Woman upset with scale

What we just didn’t understand. I dated a woman in my twenties that would prep herself for big nights out. She would get up on a Saturday, go for a run, have a workout, eat clean all day, and then when it came time to get ready that night, she would weigh herself back in, only to discover that she had gained 5 pounds over the course of a day spent trying to minimize exactly what had just happened on the scale. I remember how devastated she would be, blaming herself for overeating, or somehow being lax in her workout. The scale caused devastation. I remember her scrapping a new dress over those 5 pounds, or on one occasion, refusing to go out and canceling plans altogether. She blamed herself, and would vow to redouble her efforts to beat the number on the scale. Not understanding the natural (and totally normal) reasons for her weight fluctuation caused real harm. 

Did you know that on average, a woman’s weight can easily fluctuate up to 5 pounds in a single day?

Woman upset after weighing herself on a bathroom scale

Are you really gaining weight? No. The shift of 5lbs on the scale is most likely due to the movement of fluids in your body’s waste processing functions (pee and poop). Now think of all of those times that you have stepped on the scale and have suddenly and unexpectedly been gut punched by seeing a 5 pound weight gain, seemingly out of nowhere. It’s happened to me countless times in my life, and I’ve beaten myself up over this exact scenario, and I’m pretty sure you have too. No more. Let’s replace judgement and fear with a bit of knowledge. Here are the 7 main causes of unexpected daily weight gain, also known as scale fright. 

You are eating foods loaded in salt. When you eat salty foods, your body holds onto more water to balance out all of that salt in your bloodstream. The extra water is flushed out once it dilutes the excess salt, but it can cause a noticeable, temporary spike on the scale. 

You might be eating foods heavy in water. Any foods that hold a lot of H2O will cause a temporary increase on the scale. Once your body finishes processing the excess water in these foods, it will flush it out of your system and your weight will settle back to normal. Examples of foods that contain a lot of water include: fruits, vegetables, soups and smoothies. Don’t avoid these foods, and don’t stress them. 

You’re having your Period. Hormonal changes can cause the number on your scale to jump, depending on where you are in your cycle. Again, this is entirely normal & temporary. Estrogen can cause water retention, and Progesterone acts as a natural diuretic, and feeling bloated and temporarily heavier is part of the process. 

Woman recovering after intense workout

New Workouts. Changing up your workout routine, maybe finally shifting to the incredible benefits of strength training to melt fat and transform your body

BodyRock Beginner Bootcamp

(try our Beginner Boot Camp on BodyRockPlus here if you are looking to start working out again - get a full year of unlimited access for just $69 with code XMAS69), or upping the intensity of your workout can cause a temporary uptick in weight. When you workout, you cause micro tears in your muscles. This is actually a really positive thing, because your body repairing these tears is actually what makes your muscles stronger. This process of repair that happens after you train can cause inflammation, which means an increase in fluids and tissues as the body goes into repair mode. Always make sure that you give yourself enough recovery time, and this will naturally resolve itself as your body becomes accustomed to the demands of your new workout routine. 

You’re Thirsty. Dehydration can lead to your body retaining more water as a survival mechanism. If your body needs water, and it’s been a minute since you’ve hydrated, your body is going to assume it’s danger time, and will start doing whatever it can to keep water handy, which will cause the scale to bump up. Simply making sure that you are drinking enough water will take care of this one. 

Too Much Alcohol. Alcohol causes the body to lose water, which as we just discovered, can cause emergency water retention. Alcohol can also lead to less than great food choices, including fast foods that are loaded in salt (see above) and high in carbs (see below). 

You ate more carbs than usual. Did you know that carbs store water in your body? These delicious little bastards store 4 grams of water for every gram of glycogen that is produced from carb digestion. This 4:1 ratio of water to glycogen retains a lot of excess water in your body. The good news is that once the glucose is broken down and used for energy, the water gets released. Now imagine the temporary impact of Alcohol, salt and carbs. Fries anyone?

Please tell me…what is my real weight?

What is my real weight on the scale?

With all of this going on continuously, is there even such a thing as having an actual weight that can be expressed with a single number?

Your real weight is more of a range than a specific number. The trick is not to freak out or get frustrated now that you have the knowledge to understand why this is happening. 

To get as close to what your real weight is as possible, experts recommend that you weigh yourself at the same time of day, preferably first thing in the morning, after you’ve used the toilet. To get even more precise, ditch all of your clothing. If you are going to weigh yourself, do a weekly weigh in following these principles.

Other methods that we specifically recommend here at BodyRock include skipping the scale completely and tracking metrics like how your clothes fit, or how you look in the mirror. As we’ve explained in this article, it’s easy for your weight to swing up or down by 5 pounds daily, and being fixated on those changes on the scale can be a bit crazy making. Weight fluctuation is normal, don’t sweat it. 



1 comment

Hello, when do you expect the Body Bar to be back in stock? Thank you.

Gabby December 29, 2021

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