Health / Weight Loss

What’s the Deal With Weight Fluctuations?

Sometimes the scale isn’t being completely honest with you.

It’s safe to say we all have a love-hate relationship with the scale. One one hand, it’s a helpful way to monitor exciting progress made from any weight loss efforts.

On the other hand, it’s a source of frustration when we don’t see the progress we hoped for. It’s can be super disheartening. But it’s also super common. Weight fluctuations occur all day, every day.

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It’s pretty self-explanatory, but a weight fluctuation is the repeated loss and gain of body weight throughout the day.

And so, while, yes, those numbers you read are accurate, not all weight is the same. Much of the weight gain and loss you see throughout a single day is completely temporary, and, usually, not even related to actual body fat.

There are several different things that can tilt the number on the scale one way or another. Everything from your water intake to your hormones can play a role in weight fluctuations.

So, to ease any potential panic, we tapped David Nazarian M.D. at My Concierge Doctor in Beverly Hills, to tell us more about what causes these shifts.

Read on to learn more and understand you can’t trust everything you read on the scale.

Water Intake and Retention

Water is a major culprit when it comes to rapid (we’re talking hourly) weight fluctuations.

When you drink a large—or even average—amount of water during the day, it sits inside your body until it’s eventually dispelled.

The continual intake and removal of fluid can dramatically shift the number on the scale. That said, there’s no reason to lower your water intake either.

When you restrict your water intake, you risk dehydration, which can lead to water retention. Water retention can happen as a result of a number of things and it also contributes to the number you see on the scale.

Consuming a lot of sodium-rich foods, getting your period, taking certain medications, and excessive drinking, can all lead to water retention. In fact, even long-distance travel can cause your body to hold onto water.

If you feel like water weight and retention is a problem for you, try reducing your salt intake, lowering your alcohol consumption, and taking a look at your medications’ side effects.

To get a better idea of your actual weight, weigh yourself in the morning after using the bathroom. And remember to drink adequate amounts of water daily to fight off dehydration and encourage real weight loss, says Dr. Nazarian.

Food and Digestion

We know what you’re thinking: of course food affects weight. But we’re talking daily weight fluctuations here. The same way water can up your numbers, food can also cause a perceived weight gain.

Hold the panic, though. Just like the water weight, this isn’t necessarily a real weight gain or increase in fat.

Every time you eat something—especially a large meal—you’re putting the literal weight of the food inside of your stomach. This is also temporary, usually lasting only until you dispose of the weight (aka use the restroom).

The type of food you eat can play a role, as well. Stored carbohydrates in the body hold water, so if you decrease the amount of carbs you eat for a time then go back to your normal diet, you may experience an increase in water weight.

So, cutting some carbs will result in lower scale numbers. Hence why low-carb diets seem so crazy effective in the beginning.

Does this mean you should decrease the amount of food you eat or skip meals? Not at all.

“Skipping meals or not eating enough can significantly decrease the metabolism,” says Dr. Nazarian. “Long term weight loss can be achieved by eating smaller meals more frequently throughout the day.”

So even if you see an increase in the number on the scale after a big meal (say, Thanksgiving dinner), don’t overcorrect and wreck your metabolism.

One more thing to consider here is your digestion. If you experience IBS, a sluggish digestive system, or constipation you may notice a short-term increase in weight.

As mentioned before, this isn’t a real weight gain and will decrease when the body rids itself of the waste.

Working Out

Getting in your daily sweat sesh can also have both a positive and negative effect on your weight fluctuations.

This is another case of water intake and output. If you push through a challenging workout (we’re talking “Long-Winded Run” or “Sweat Dripping”) with no time to drink water, you’ll be sweating out a minor amount of water weight.

Likewise, if you’re hydrating throughout your workout, you’ll be holding water in your stomach until your next bathroom break.

Muscles also can actually retain water post-workout, especially if you’re new to strength training.

When you work your muscles (be it with weights or bodyweight), you cause micro-tears within the muscle.

These tears repair themselves, resulting in stronger muscles (yay!) and fluid retention for a few days.

Glycogen and Vitamin Stores

Glyco-what? Glycogen is a form of glucose that acts as an energy store in our bodies. When we eat carbohydrates they’re stored as glycogen throughout the body (most notably in the liver and muscles).

Each gram of carbs can cause your body to retain anywhere from two to four times that amount of water.

Thought exercise: Imagine you’re on a low-carb diet so your glycogen stores are lower than normal. Then, one day, you decide to forget the diet because of a holiday, birthday, or just because!

Your body now has way more glycogen than it did before, carrying more water with it.

A high-carb day can increase your scale weight by as much as seven pounds—but remember, this is not actual weight gain!


All in all, daily weight fluctuations are completely normal and nothing to worry about. The scale is extremely convenient and great for tracking progress long term, but will only frustrate you in the short term.

To track your progress most efficiently, weigh yourself once a week at the same time; in the morning, after having used the restroom and before eating breakfast.

This will track your true weight, without driving you crazy in the process.

If you’re in need of workouts, we have an app for that! Download the Aaptiv app today and see the newest classes we’ve added.

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