Why It's Normal for Your Weight to Fluctuate from Day to Day

Seeing a different number on the scale every day can be frustrating depending on your goals. Ahead, experts answer the question, "why does my weight fluctuate so much?"

If you're taking on a new weight loss goal, your instinct might be to hop on the scale twice a day and hope for a consistently lower number each time. The thing is, daily weight fluctuation is normal. Just because you see that number go up or down from one day to the next doesn't mean you aren't on track to lose or gain weight over the long term. So, if you're wondering, "why does my weight fluctuate so much?" this article's got you covered.

Why Does My Weight Fluctuate So Much?

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. And while there isn't necessarily a one-size-fits-all answer to questions such as "why does my weight fluctuate so much?" and "what causes weight fluctuation?" water retention is often the culprit. That is, of course, as long as you're eating healthy and exercising.

"Eating, drinking, urinating, having a bowel movement, and exercise can all impact your body's water composition and therefore weight," she says. For example, high-carb and high-salt foods can cause H2O retention and a boost in poundage, while exercise can lead to temporary water and weight loss. (That being said, your workout could technically cause weight gain as well, but that's also totally normal.)

So don't think much of it if you notice daily weight fluctuation. "Weight gain due to water fluctuation should normalize in a day or two when you resume exercising and eating a healthy diet that's low in salt, refined carbs, and simple sugars," says Dr. Petruzzelli. All the more reason to take an overview of your weight changes rather than weighing yourself constantly.

Similarly, there's also no one answer to the question, "how much does weight fluctuate from night to morning?" Water retention can also be to blame here, yes, but any significant "overnight weight gain" (i.e. suddenly adding on 5 pounds from p.m. to a.m.) is "not a thing," according to the Cleveland Clinic. And need not forget about your good friend Aunt Flo. Next time you step on the scale only to wonder, "why does my weight fluctuate so much?" consider your cycle. Period weight gain is totally normal.

However, if those extra pounds keep showing up on the scale after you've returned to your regular routine for about a week, it may be due to another lifestyle factor. A daily weight fluctuation range of 0 to 5 pounds won't prevent you from hitting your goals, according to Joseph Colella, M.D., a bariatric surgeon at Wheeling Hospital in West Virginia. "Most people can recover 5 pounds rather quickly with minor tweaks to their calorie intake and physical activity."

And if the scale shows a 7-pound jump for longer than a day or two, alcohol consumption could be one cause. "Alcohol stimulates your appetite and wrecks your self-control regarding the amount of food that you consume," explains Dr. Colella. Keep in mind that in addition to diet, some medications and health conditions can also lead to potential weight gain and turn out to be the answer to the question, "why does my weight fluctuate?"

How to Track Your Progress, Accounting for Daily Weight Fluctuation

Despite the fluctuations, you can use a scale to your advantage to track and meet your goals. But first, if you have a history of disordered eating, stepping on the scale in general — nevermind daily or weekly — can be triggering and more often than not, should be avoided. (

It's also important to note that you do not necessarily need a scale to meet your goals — yes, even weight loss goals. Just remember that health is way more than just a number and focusing on how you feel will be more effective in the long run. Becoming stronger physically and mentally — and loving your body because of it — is far more important than whatever number ends up flashing on the scale.

Got all that? Good. Now, if you want to lose just a few pounds, jumping on the scale every day can "give you a regular barometer and over time, a trend line that you can use to reflect on what you ate and what you weighed," according to Dr. Colella. And while daily weigh-ins might help some reach their goals, constantly stepping on the scale can encourage others to develop an obsession with numbers. Not only can this derail your progress but it can also take a serious toll on your mental health. So if you find that you can't stop fixating on your number, it might be best to stop using the scale every day (and, potentially, overall).

You might also want to ditch daily check-ins if you're aiming to lose more weight than, say, a few pounds. Avoid unnecessary stress by checking in once a week (or every few weeks), and instead, concentrate on maintaining a healthy diet and moving your body on the regular, he says.

However often you do face the scale, be consistent. Weigh yourself naked first thing in the morning after using the bathroom and always using the same scale, suggests Dr. Petruzelli.

Consider other methods of progress measurement, especially if your weight-loss goal is more than a few pounds since a scale doesn't record all positive changes. Regularly having your body composition checked can determine your body's exact fat, muscle, and water content, and the way your clothing fits can also be helpful, says Dr. Petruzelli. If your clothes fit or are too loose but the scale says you've gained weight, the gain is probably muscle, she explains.

The bottom line: Weight fluctuation is normal, but if the scale rises 5 or more pounds for longer than a day or two, chances are it's more than simply water weight. Don't freak out — just pay attention to your body and call your doc if you are still having trouble. After all, consulting a professional is always a good idea. (Up next: 8 Medical-Related Reasons for Unexplained Weight Gain)

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