Seven reasons why drinking water may help you lose weight.

1. Water may naturally suppress your appetite.

When you realize you’re hungry, your first impulse may be to find food. But eating may not be the answer. “Thirst, which is triggered by mild dehydration, is often mistaken for hunger by the brain,” says Melina Jampolis an internist and board-certified physician nutrition specialist. “You may be able to decrease appetite by drinking water if you are, in fact, low in the water, not calories.”

What’s more, drinking water can promote satiation because it passes through the system quickly, stretching the stomach. “This sends messages to your brain signaling fullness,” Jampolis says.

Elizabeth Huggins, a Registered Dietitian Nutritionist at Hilton Head Health, adds that though the results are temporary, “consuming water shortly before eating may help decrease food intake.” Research supports the theory: People who drank two glasses of water immediately before a meal in a small 2016 study ate 22% less than those who didn’t drink any water prior to eating.

About two cups should fill your stomach enough for your brain to register fullness.

2. Drinking water may stimulate your metabolism.

It’s possible that drinking water stimulates your body’s metabolism and energy expenditure, ultimately helping with weight management, according to Huggins.

In an eight-week study published, when 50 girls with excess weight drank about two cups of water half an hour before breakfast, lunch, and dinner without any additional dietary changes, they lost weight and saw reductions in body mass index and body composition scores.

It’s not magic: Drinking water appears to stimulate thermogenesis, or heat production, in the body, particularly when it’s chilled. The body has to expend energy to warm the fluid to body temperature, and the more energy expended by your body, the faster your metabolism (the process by which your body converts what you eat and drink into energy) runs. Specifically, drinking about two cups of 71°F water led to a 30% average increase in the metabolic rates of 14 healthy adults in a small 2003 study published in the Journal of Clinical Endocrinology & Metabolism.

Before you fill your glass and load your plate, though, keep in mind that the effects of thermogenesis probably won’t create substantial calorie deficits that result in weight loss. “Even if the effect is negligible, it is important to stay hydrated,” Huggins says, noting that there are few, if any, downsides to drinking more water.

3. Drinking water could help reduce your overall liquid calorie intake.

Because water contains no calories, filling your glass with H2O instead of higher-calorie alternatives such as juice, soda, or sweetened tea or coffee can reduce your overall liquid calorie intake. Choose water over the standard 20-ounce vending machine soft drink, and you’ll drink 250 fewer calories, Huggins points out.

As long as you don’t “make up” for those calories — i.e., walk out of the coffee shop with a muffin and water instead of your usual flavored latte — the calorie savings can add up quickly, she says.

Also interesting: Although diet soda contributes no calories, replacing diet beverages with water may be a factor that contributes to weight loss in certain groups of people. Overweight and obese women who replaced diet beverages with water after their main meal showed greater weight reduction during a weight-loss program in a 2015 study published in The American Journal of Clinical Nutrition. The researchers noted that the extra weight loss in those who drank water could be attributed to consuming fewer calories and carbohydrates, but more research is needed. All that said, since many diet beverages still hydrate and reduce calorie intake when used as a replacement for sugary beverages, they may help certain individuals lose weight.

4. Drinking water helps during exercise.

Water is essential to the body during exercise: It dissolves electrolytes — minerals that include sodium, potassium, and magnesium — and distributes them throughout the body, where their electrical energy triggers muscle contractions required for movement, Jampolis explains. An electrolyte imbalance can lead to cramping, but that’s not the only side effect of drinking too little.

“When muscle cells are dehydrated, they break down protein (aka muscle) more quickly and build muscle more slowly, so your workouts are much less effective,” she says.

What’s more, the body loses fluids more quickly during exercise because it generates heat that’s shunted to the skin’s surface, where perspiration and subsequent evaporation (a cooling process) help with temperature regulation.

Staying properly hydrated also helps maintain your blood’s volume, so you can optimize the expansion of blood vessels at the skin’s surface to release heat, Jampolis says.

“If your body can’t dump excess heat via sweating, you’re setting yourself up for heat exhaustion or worse,” she says. “Being adequately hydrated can improve your workouts by decreasing fatigue, which can allow you to work out longer and burn more calories.” That’s why it’s so important to hydrate before and throughout your workout, not just when you start to feel thirsty.

5. Water helps the body remove waste.

Drinking water facilitates the production of urine, which is largely made up of water, and the movement of feces, since water keeps stools soft. In other words, the more hydrated you are, the easier it is for your system to move things along and the less likely you are to suffer from constipation and bloating.

In addition, adequate hydration promotes kidney, flushes harmful bacteria from the urinary tract, and prevents kidney stones, which can occur with more concentrated urine, according to Huggins.

6. The body needs water to burn fat.

Upping your water intake may increase lipolysis, the process by which the body burns fat for energy, according to animal studies published in Frontiers in Nutrition. “We’re not certain of the mechanism, but mild dehydration decreases lipolysis, which may be due to hormonal changes,” says Jampolis, who was not associated with the review. Another theory posed in the animal studies: Water expands cell volume, which could play a role in fat metabolism. However, it remains unproven among human subjects.

7. Water may improve motivation and reduce stress.

When you’re dehydrated, you may experience symptoms such as fatigue, dizziness, and confusion — and who makes healthy decisions under those conditions? Dehydration, the researcher of the 2016 mini-review found, also may be linked to sleepiness and reduced alertness. And another study, published in the International Journal of Sports Medicine, found that dehydration increases your body’s production of cortisol, the stress hormone.

“These symptoms could affect your motivation to exercise, cook at home, and make better food choices,” Jampolis says.