Can drinking water actually help you lose weight?

Can drinking water actually help you lose weight?

When you're trying to lose weight, simple lifestyle changes like taking longer walks outside, stressing less, and drinking more water may seem like the least overwhelming and perhaps most sustainable course of action. But can increasing your H2O intake really help you achieve your goals? And if so, how much water should you drink to lose weight? Here, two nutrition professionals break it down.

Why is water even important?

Before you get the DL on water's potential role in weight loss, you should know the key benefits of staying hydrated in the first place. For starters, drinking the recommended amount of fluids every day—be it plain water, herbal teas, coffee, smoothies, or soups and yogurt (yes, liquid foods count)—will help keep your body functioning smoothly, says Molly Kimball, RD, CSSD, a registered dietitian at Ochsner Fitness Center in New Orleans and host of the FUELED Wellness + Nutrition podcast. Fluids play a role in certain metabolic processes, such as digesting carbohydrates, fats, and proteins and breaking down the vitamins you eat into a form that can be absorbed and used by your body, "and therefore our fluid status is necessary for all of these things to take place," she explains. Plus, research shows that hydration helps your body eliminate waste (via sweating, urination, and bowel movements), reduces the risk of kidney stones, and relieves skin dryness, says Jennifer McDaniel, MS, RDN, CSSD, LD, a registered dietitian and the owner of McDaniel Nutrition Therapy.

Aside from supporting basic body functions, consuming enough fluids is key to keeping your energy levels high, says Kimball. "One of the first signs of even a [slight] dehydration is fatigue — feeling a little sluggish and tired," she says. "When someone says they have that afternoon energy slump, before I even look at what they eat, I look at how they hydrate themselves throughout the day. And often they just don't get enough fluids." For the same reason, your fluid intake can also affect how you feel during exercise; You might feel fresh and strong while working up a sweat if you're adequately hydrated, and if not, you might feel "like you've already gone for a jog when you first get going," says Kimball.

To figure out exactly how much fluid you need for your body to function properly, Kimball recommends taking your weight in pounds and then dividing it by two—the result is the amount of fluid in ounces you should try to consume each day. For example, if you weigh 150 pounds, you need to drink 75 ounces of fluid per day, she explains. However, for every pound of sweat you lose, you should consume 16 ounces more (think: after spin class or while hiking on a hot, humid day), she says. "For example, if you normally do a morning bike class or a morning boot camp class, it might be beneficial to do this a few times...[to] weigh yourself before and then after," she says. "Then you'll get a feel for how much sweat you typically lose during this workout and [can] aim to replenish at least 16 ounces for every pound of sweat lost." (Hold on, is sweating good for you?)

Can drinking water help you lose weight?

It could reduce your intake of carbohydrate-rich foods

Even mild dehydration can leave you feeling tired and irritable, and in those cases, you might turn to beneficial refined carbs (which are low in satiating fiber) and sugar for an energy boost, says Kimball. The reason: Carbohydrates are digested quickly, raising blood sugar levels in about 15 minutes and releasing mood-boosting serotonin and satiating hormones, Abby Chan, MS, RDN, a registered dietitian and co-owner of EVOLVE Flagstaff in Arizona, previously told Form. "It could be sugar, it could be chips, it could be anything, but we're looking for carbs for that pick-me-up or that mood booster to kind of fix it," says Kimball. "But often what we're experiencing or why we're feeling that is due to that little bit of dehydration."

Of course, carbohydrates are a good thing. Once broken down into glucose, carbohydrates are your body's primary source of fuel, and they should make up 45 to 65 percent of your total daily calories, according to the U.S. Department of Agriculture's Dietary Guidelines for Americans. Excess glucose – i.e. h. Glucose, which is consumed but not used for energy - is stored in the liver, muscles and other cells for later use or converted into fat, according to the Mayo Clinic. Sugars - which typically provide little nutritional value but have 4 calories per gram - can contribute to weight gain, according to the Mayo Clinic. Case in point: Reducing added sugar intake was associated with a slight decrease in body weight, while higher intake was associated with weight gain, according to a 2018 review published in the BMJ.

"That means keeping track of your fluid intake and getting your recommended amount every day to curb mindless snacking on high-carb, low-fiber, but momentarily energy-boosting foods, Kimball says.

It could make you feel fuller before a meal

When you sip water (or another liquid), your stomach expands, and certain neurons that detect stretching in the organ tell your brain that you're full, says McDaniel. Consequently, "if we drink water before a meal, there is the potential for us to reach satiety sooner based on these cues," she says. "If someone tends to eat large amounts, having something like herbal tea or broth-based soup [before eating a meal] can definitely help give you that feeling of volume," adds Kimball.

Research also supports this idea: A small 2007 study found that middle-aged and older men consumed less during a meal when they drank 500 milliliters (about 16 ounces) of water 30 minutes before eating. Similarly, a 2009 study found that middle-aged and older participants who followed a low-calorie diet and drank 500 milliliters of H2O before each of their three daily meals for 12 weeks lost about 2 kilograms (about 4.4 pounds) more than others who just followed a low-calorie diet.

It could increase your metabolism slightly

Contrary to popular belief, increasing your H2O intake won't seriously rev up your metabolism (aka the process by which your body converts food and drink into energy), says Kimball. “Research shows that when you drink water, the process of warming the water – when it is chilled – requires energy and therefore slightly increases your metabolism,” adds McDaniel. "While this benefit may be present, it plays a very minor role in the total number of calories burned in a day."

Additionally, an increase in metabolism can only occur if you're chronically dehydrated—meaning you've been lagging in your fluid intake for days or weeks, says Kimball. "I wouldn't say it will always happen, but it is possible that you have a slightly lower metabolic rate [if you're dehydrated]," she explains. "So if you drink more fluids to counteract that, you might see a slight correction in that metabolism, that metabolic rate, but it's not really going to be a big turning point for us." in Weight Loss (Related: This Dehydration Test on TikTok Will Tell You If You're Parched)

And to date, the most consistent research supporting the link between increased water intake and weight loss through improving metabolism comes largely from rodent studies. This research has shown that increased fluid intake can increase metabolism. In turn, the function of mitochondria — the structures within cells that harness energy in food — can improve, which can increase fat loss in certain cells, according to a 2016 review published in Frontiers in Nutrition.

TL;DR: Staying hydrated and sipping chilled water might minimally increase your metabolism, but its effects on fat loss in humans have not yet been proven.

How much water should you drink to lose weight?

If you're wondering, "How much water should I drink to lose weight?" Know that there is no set-in-stone fluid recommendation for weight loss. The above studies that showed a relationship between pre-meal H2O intake and food intake during a meal both involved 500 milliliters of water. And a 2008 study of 173 "premenopausal, overweight" women following various popular weight-loss diets found that increasing water intake from less than 1 liter (nearly 34 ounces) per day to more than 1 liter was associated with a 5-pound weight loss over the course of a year.

However, 34 ounces of water probably isn't enough H2O to adequately hydrate your body, as it's recommended to swallow the same amount of fluid in ounces as half your body weight, says Kimball. Whether you want to lose weight or not, aim to reach your personal quota, she says. (See also: What Happened When I Drinked Twice as Much Water as Usual for a Week)

The most important findings

Drinking water and consuming fluids can potentially contribute to weight loss, either by curbing your cravings for carbohydrates or sugar, increasing satiety, or increasing your metabolism. But there is no magic answer to “How much water should I drink to lose weight?” — Water is also not an elixir for losing weight. Instead, hydration should simply be viewed as a single component of a holistic strategy for achieving your health goals, which includes achieving satisfactory macronutrients (e.g., say Kimball and McDaniel. "It's kind of a very moderate [approach to weight loss] but none of it is like, 'Oh, drink that much water and you'll melt it off yourself,'" says Kimball.

And if you're thinking about losing weight, both nutrition professionals recommend making an appointment with a registered dietitian or your doctor before drinking a gallon or two of water. “The money you would spend [on a consultation] can pay off so much more in the long run because it gives you an education,” says Kimball. "It can save you money from trendy mistakes you may make later, and it helps you learn more about your own relationship with food. ...so it can help you learn a bit more about a personalized approach for yourself." (See also: Black Nutritionist Recipes, Healthy Eating Tips, and More)