Your Scale Is Lying to You! 5 Reasons Your Weight Fluctuates (2024)

If you're anything like us, you have days where you obsessively check your weight, hoping the number on the scale will drop at least half a pound (unfortunately, those days tend to become more and more frequent in the middle of bikini season).

But before you get all bummed out about your "number," you should know the facts (and myths) about what affects your weight.

We asked Karen Ansel, registered dietitian in New York and spokeswoman for the American Dietetic Association, to give us the skinny on our five most pressing weight questions:

1. Is it true that we weigh less in the morning?

Generally, yes, because you don't have the added weight of a recent undigested meal. During the day, when you're eating and drinking, those foods (and fluids) add weight—at least until they're digested and excreted. Just a cup of water adds half a pound, for example—and 20 percent of most meals are water, which adds up to a lot of extra weight. Since you're not eating or drinking during the night (unless you get the midnight munchies), your body has a chance to remove extra fluids (that's why you pee so much in the morning when you wake up). So weigh yourself in the morning ... after you pee.

2. After we go No. 2?

Yes—for obvious reasons! But for those of you who aren't squeamish, we'll explain. When you have a bowel movement, you're emptying your colon. Depending how much you go, that visit to the ladies' room can add up to half a pound a day—hence the reason you feel so much lighter after you poop. If you're the type of person who takes care of business first thing in the morning, weigh yourself right after you go. If you're more likely to go after breakfast, weigh yourself first so your meal doesn't add extra pounds to the scale. Either way works as long as you're consistent.

FAQs

Why does my weight fluctuate on the scale? ›

Factors like sodium and carbohydrate intake, exercise, food intake, bowel patterns, a person's menstrual cycle, medications, and alcohol can all contribute to daily swings in the number on the scale. Weighing yourself weekly, rather than daily, can help you get a broader view of the changes in your body weight.

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Why does my scale fluctuate 5 pounds? ›

Daily weight fluctuation is normal. The average adult's weight fluctuates up to 5 or 6 pounds per day. It all comes down to what and when you eat, drink, exercise, and even sleep.

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Can a scale lie about your weight? ›

Bathroom scales are fickle devices. They can give you a different weight from day to day, or even moment to moment. Sure, the human body fluctuates over the course of the day and there are some crappy scales out there, but even relatively good scales can seem to be wildly inaccurate.

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What happens when your weight fluctuates? ›

Fluctuation in large amounts throughout your life — that lose-gain-lose-gain cycle so many of us battle, the so-called “yo-yo dieting” — can tax the cardiovascular system, set the stage for diabetes, slow metabolism and make it increasingly difficult to lose weight. It also can permanently stretch skin out of shape.

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Why does my weight fluctuate on digital scale? ›

#1 Every time a digital scale is moved it needs to be calibrated. Initializing the scale resets the internal parts allowing the scale to find the correct “zero” weight and ensure accurate readings. If the scale is moved and you do NOT calibrate it, you are likely to see fluctuations in your weight.

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Is it OK for my weight to fluctuate? ›

The reality is, small changes in weight are completely normal and expected. Body weight can shift throughout the week and even during the day. In fact, an average adult can lose or gain two to eight pounds over the course of a few days.

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Is it normal to fluctuate 5 pounds in a day? ›

“Everyone's weight fluctuates throughout the day, and especially from morning to night,” says dietitian Anne Danahy, MS, RDN. “The average change is 2 to 5 pounds, and it's due to fluid shifts throughout the day.” If you see fluctuations of less than 5 pounds, you needn't worry.

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Why does the scale say I gained 5 pounds after eating? ›

Since many people can't eat enough in a day or two to actually gain 5 or 10 pounds, if you notice a dramatic increase on the scale, chances are it's due to water, says Anita Petruzzelli, M.D., owner and medical director of BodyLogicMD.

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How much weight fluctuation is normal? ›

Average weight fluctuation

It's perfectly normal for your weight to fluctuate by 1-2 kilograms or up to 4.4 pounds over a few days. Depending on your daily routine and when you weigh yourself, your weight can fluctuate to this extent in just one day. Some aspects of weight fluctuation are entirely out of your control.

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When should you weigh yourself for true weight? ›

You should step on the scale first thing in the morning. That's when you'll get your most accurate weight because your body has had the overnight hours to digest and process whatever you ate and drank the day before. And you should try to turn that step into a regular part of your routine.

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How do you know if a scale is lying? ›

Weigh yourself while holding an object.

Then, check to see if the weight goes up by the exact amount that you are holding. If it does, then the scale is accurate. For example, if you step on the scale and it says 145, then it should go up to 150 when you step on again while holding a 5 pound dumbbell.

How much weight fluctuation is too much? ›

“The amount of fluctuation in weight can vary from person to person, depending on their individual health and lifestyle,” says Rodríguez Ruiz. The safe range for weight fluctuation usually falls within one to six pounds. And, if it's significantly more than this, it might be time to talk to your doctor.