What Is Water Weight? And Should You Be Trying to Lose It?

You've been eating healthy, exercising and doing all the "right" things. So why is your weight fluctuating so much each day?

It's frustrating, to be sure. But is it unusual? Not at all.

In fact, small shifts in your weight from day to day — or even throughout the course of a single day — are often just a sign of water weight.

What is water weight?

Water makes up a huge portion of your body, and it needs to be there — in your blood vessels, your tissues, your cells — because it plays critical roles in vital functions like regulating body temperature, maintaining blood volume, carrying nutrients, removing waste, lubricating joints and more.

"About 60% to 80% of your body is water, so it absolutely affects the numbers you see on a scale," says Dr. Garth Davis, a weight loss surgeon at Houston Methodist. "This becomes more obvious when the body is retaining more water than usual, for one reason or another."

What causes water retention?

Many factors can lead to your body holding onto water and contributing to water weight gain, including:

• Hormonal changes: Particularly during a woman's menstrual cycle, hormonal shifts can cause temporary water retention.
• Diet: High-sodium foods, refined carbohydrates and alcohol can all cause your body to hold onto more fluid.
• Dehydration: Not drinking enough water (or losing too much water) can actually cause your body to compensate by retaining fluid.
• Glycogen stores: Your body stores energy in the form of glycogen, mostly in muscle tissue. "When your glycogen stores go down — for instance, when you're on a low-carb diet, like the keto diet — you lose the water stored with it," explains Dr. Davis. "That's why the scale often drops quickly at the start of these popular crash diets, the water weight that's lost."
• Medical conditions: Certain heart, liver and kidney issues can cause your body to retain more water than usual.
• Medications: Some medications, like steroids and blood pressure drugs, can contribute to water retention.

If you're experiencing unexplained swelling or persistent weight gain from fluid, check with your doctor. It could be a sign of an underlying health condition.

Is water weight "real" weight gain?

Yes ... but also no.

Water weight can shift based on everything from what you eat and drink to hormone levels and glycogen stores, which means it can fluctuate throughout the day or from one day to the next.

"So yes, water weight is real in that it affects your total weight," says Dr. Davis. "But it's not an indicator you are gaining fat. Usually, weight gain from water weight is temporary and related to hormones or your diet."

This is why experts recommend weighing yourself at the same time every day — ideally first thing in the morning. While it can be frustrating to see the scale go up and down, those shifts don't necessarily reflect meaningful changes in your overall health.

"This is also why I prefer monitoring weight via waistline circumference instead of numbers on a scale," Dr. Davis adds.

How to get rid of water weight

Can you lose water weight quickly? Yes, but a word of caution: "While it's possible, doing so isn't always safe or sustainable," says Dr. Davis.

Some people try to shed water weight using restrictive diets or over-the-counter diuretics, but these approaches can come with risks. "Taking diuretics without physician supervision can be very dangerous if it leads to severe dehydration," he says. "As for crash diets, like keto, all you're really losing in the first few days is water — which, if we're being honest, isn't what most of us are hoping to lose when the aim is to get healthier."

Instead, you can help manage water retention with these more balanced approaches:

• Cut back on sodium – limit overly processed or salty foods
• Stay hydrated – adequate water intake actually helps balance fluid retention
• Be physically active – movement promotes circulation, which can help move excess water out of the body
• Eat a well-balanced diet – focus on fruits, non-starchy veggie and whole grains
• Don't panic over short-term changes – focus on long-term patterns, not day-to-day fluctuations

If your goal is weight loss, there are far more effective and sustainable strategies than trying to lose water weight. Talk to your doctor about the right approach for you.

"One of the best things you can do is understand your body's pattern," adds Dr. Davis. "Some water weight is normal, and an otherwise healthy person with no symptoms or underlying medical issues doesn't need to be concerned about it."