You may be wondering how often should I weigh myself. One of the first things you do when you go to the doctor for your annual physical is step on the scale. But chances are you have a scale of your own at home, which means that you have access to knowing how much you weigh more than just once a year.

Even though the scale is there and ready to use whenever you want, how often should I weigh myself? Plus, what does that number really tell you about your health, anyway? Here’s what research and experts say about how often check in on your weight—whether it’s to see how your weight loss journey is progressing or how your weight maintenance is going.

What does weight even tell you?

The number you see on the scale is the sum of your lean body mass—which includes muscle, organs, bones, and fluid like water and blood—and fat mass (also referred to as adipose tissue), Susan Kleiner, PhD, a dietican in Washington and national nutrition consultant, tells Health.

  • “Your weight is simply representation of the relationship of your body to gravity. It tells you nothing about how healthy you are, if you’re pretty, or any other moral assumptions we assign to the number,” says Kleiner.
  • Yes, weight is tied into your body mass index (BMI), a screening method for how your weight might relate to disease outcomes. BMI, which is your weight in kilograms divided by the square of your height in meters, tells you whether you fall into the underweight, normal weight, overweight, or obesity category. But as Health previously reported, BMI has its drawbacks and may not be an accurate predictor of health for everybody.
  • Your weight—and BMI, for that matter—also doesn’t tell you the percentage of lean mass to fat mass (aka, your body fat percentage), which can be an important indicator of health. The more muscle you have, the higher your lean body mass, which equates to a lower body fat percentage.
  • But even though your weight alone won’t tell you your body fat percentage or overall health risk, research has shown that knowing your weight can help you engage in healthier behavior. For instance, one study found that weighing daily led participants to engage in more weight control habits, like cutting down on sugary foods, eliminating excess snacking, and eating out less.

How often should I weigh myself, if at all?

If you’re embarking on a journey to improve your health, figure out whether weight loss should even be a part of that journey. “You can improve your health through nutrition and exercise without losing an ounce.

If that’s the case, you don’t need to weigh yourself at all,” says Kleiner. “But if weight loss is something you desire, understand it’s a long-term process. You’ll see the scale go up and down, and only you can decide if weighing yourself will help or hurt your efforts.”

Here’s another thing to consider if you’re wanting to lose weight. “As your weight increases, you gain not only fat, but also muscle mass to support the added fat. About 20% to 35% of excess weight is lean tissue, through the addition of muscle and bone mass,” Donald Hensrud, MD, associate professor of nutrition and preventative medicine at the Mayo Clinic College of Medicine, tells Health. “You don’t need to lose the muscle you’ve gained, so weighing what you did in high school (or whatever arbitrary time point) isn’t realistic or helpful.”

Maybe your goal isn’t weight loss, maybe it’s weight maintenance. Either way, regular weighing might be beneficial. A 2014 review examined the literature published between 1967 and 2013 regarding the use of daily self-weighing to control body weight and found weighing daily appears to be effective at preventing age-related weight gain. The study also found that frequent weighing correlates with losing weight and keeping it off.

However, it’s not a one-size-fits-all decision.

• “For [one] person, checking your body weight daily might be a good thing. Or a different person can stay motivated by checking once a week. Yet someone else could find weigh-ins are self-destructive,” Kleiner cautions.

• A different review of medical literature found that more frequent self-weighing was associated with poorer self-esteem as well as a negative impact on body evaluation, such as body image and body dissatisfaction. And though the results were mixed, the review also showed that studies have determined that some individuals will suffer from greater depression and anxiety if they weigh themselves often.

• The review also revealed that self-weighing may be negatively associated with the development and exacerbation of disordered eating thoughts and behaviors. In fact, authors of a 2016 review wrote that, although weekly weighing is often part of the treatment for eating disorders, data suggest that even that frequency might prompt a moderately negative reaction.

• If you like the feedback weighing gives you, it doesn’t negatively affect your mood or mental health, and your health care provider hasn’t instructed you otherwise, weighing daily is likely best, Mike T. Nelson, PhD, a Minnesota-based exercise physiologist and national fitness and nutrition educator, tells Health. “The problem with weighing less frequently is it puts a lot of pressure on one measurement. Some people will starve themselves the day before or do something screwy to try to make their weight lower,” he says.

What causes your weight to fluctuate?

If you are someone who weighs themselves on a more regular basis, you might notice that your weight goes up and down, even when you’re not doing anything to purposefully lose or gain weight.

These are the most common reasons why weight spikes:

• Excess sodium. Nelson explains that salt causes your body to retain water, especially if you’re not used to eating a high amount. If you’ve ever felt puffy after a salty restaurant meal, you know how this feels.

• Carbohydrates. When we eat carbs, the energy we don’t use right away is stored as glycogen in our muscles. Each gram of glycogen carries three grams of water. This is why if you go on a low-carb diet, you’ll lose a lot of water weight in the first few weeks. The weight loss (or gain from a high-carb meal) isn’t fat, Nelson explains.

• Fiber. Kleiner is a huge fan of getting your veggies, but she says to keep in mind that if you’ve recently upped your veggie consumption or switched to more plant-based or whole foods, you’re eating more fiber. You can experience temporary constipation, which makes your weight go up.

• Hormones. “Some females can swing five to eight pounds during their menstrual cycle,” says Kleiner. “For others, three to five pounds is common.” It’s not your period itself that causes weight gain. Rather, as the Office on Women’s Health explains it, the hormonal changes during that time might cause you to crave and eat more sweet or salty foods than usual, and those extra calories can lead to weight gain. It could also be from the retention of water weight during that time.

• Stomach contents. Many people forget that undigested food can cause weight to increase, according to Nelson. If you ate late in the evening or are weighing yourself at a different time of day, the amount of food in your gut can make a difference in your weight.

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