Feeling like you’ve been inflated with a tire pump the morning after pounding a deep-crust pizza? The good news is you haven’t put on 10 pounds in mid-section fat overnight. But you can thank water retention if you awake to a nasty surprise on the scale. Here’s what water weight is, along with some advice to minimize it.

What is water weight?

Your body needs water—and lots of it—to function: In fact, 50 to 70 percent of your entire body weight is water. Keeping your body hydrated is essential for lots of body functions, including maintaining your body temperature, cushioning your joints, and getting rid of waste through sweat, pee, and poop. Exactly how much water is in your body depends mostly on your age, sex, and body composition—but what you eat, in particular, can cause you to retain a few extra pounds of water weight.

Why does your body retain extra water?

Carbs and sodium play the outsized role in excess water retention. Carbs are stored in your muscles and liver as glycogen, your body’s preferred energy source; each gram of glycogen, in turn, packs away about 3 grams of water with it, explains Nick Clayton, C.S.C.S., the personal training program manager for the National Strength and Conditioning Association (NSCA). Meanwhile, the electrolyte sodium attracts water in the spaces outside of your cells and in your plasma, says Karen Ansel, M.S., R.D., author of Healing Superfoods for Anti-Aging: Stay Younger, Live Longer. That means when you knock back a burger with fries, the heavy load of sodium and carbs store extra water weight in your tissues.

The amount of water weight your body stores can vary a lot, but the average person carries one to five pounds, Clayton says; athletes (or anyone training at least 90 minutes a day) can train their bodies to stash away double that (a good thing, he notes, because they’ll use it the next day).

Certain medications can also cause you to retain water, Health reported. Generally, these include prescriptions that manage high blood pressure such as calcium channel blockers, corticosteroids, and nonsteroidal anti-inflammatory drugs (NSAIDs). Certain diabetes medications can also cause water weight. Your doctor can discuss whether your specific prescriptions cause water retention.

However, that's not to say that these drugs cause weight gain. It's important to realize that water weight is not the same as fat loss, meaning that decrease on the scale may not change your body composition.

Which diets affect water weight?

If you’ve ever tried a low-carb diet, you’ve probably noticed the first few pounds practically fall off—and that’s due in large part to water weight. The first week you’re on a diet, almost 70 percent of weight loss is water, Clayton says, a rate which drops to about 20 to 30 percent over a couple of weeks and then stabilizes as your body starts tapping into fat stores. When you eat fewer calories than you’re using, your body doesn’t store more glycogen, and you’re using your existing glycogen stores—and water goes with it, Clayton explains.

“If you always eat carb-heavy and salty meals and then cut down on carbs and salt for a few days, you’ll be amazed at how much you’ll pee out in water weight,” says Ansel.

What are the best ways to lose water weight?

The best way to lose the water weight, hands-down, is to eat less processed junk foods (like chips, cookies, and pizza) and to load up on whole foods—especially fruits and veggies, say Clayton and Ansel.

“Highly processed foods tend to be packed with carbs and salt, so they’re a natural recipe for water retention,” explains Ansel. “On the flip side, whole foods contain potassium, a mineral that helps restore proper fluid balance in the body.” Since potassium is only found in foods like fruits, vegetables, and beans, eating a plant-based diet “is one of the very best ways to beat unwanted bloat,” she says.

Although it may seem counterintuitive, drinking more water can actually help reduce water retention, according to Health. That's because your body holds onto whatever water it has when dehydrated.

Exactly how much water weight you can expect to shed depends on a lot of factors, including your body size and composition. “I know people who were obese and lost 10 pounds in two days” on a diet, Clayton says. He notes that the average person can expect to lose one to three pounds in about two days.

Also keep in mind that regular workouts can result in less water retention, since sweating sheds water, glycogen, and sodium. “If you’re a heavy exerciser, it’s likely that you retain less water than the average person,” Ansel says. “That’s because we lose a fair amount of water-binding sodium through sweat. What’s more, when you exercise you’re also burning lots of glycogen, which also binds lots of water.”

Can you ‘flush out’ a salty meal with water?

While it’s important to stay hydrated to support your body’s core functions, you can’t “flush out” excess sodium from your system by drinking tons of water, Clayton says. Your body excretes sodium out all on its own given time (and a healthier diet); a sweaty workout can help the process along.

Does weight lifting cause water retention?

Noticed your legs or biceps look extra swoll after a hardcore bodybuilding workout? That muscle pump is actually water weight, and it’s a natural part of the healing process. “Muscles may retain water after workouts to help repair micro-tears and inflammation that occur from the stress of the workout,” Clayton says. “It’s negligible, and the additional water in there goes away in an hour or two. You probably won’t see any difference in scale next day.”

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Colleen de Bellefonds

Colleen de Bellefonds is an American freelance journalist living in Paris, France, with her husband and dog, Mochi. She loves running, yoga, and wine, and is very particular about her baguettes. 

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Health Writer
Melissa Matthews is the Health Writer at Men's Health, covering the latest in food, nutrition, and health.