Drinking water should not make you gain weight, since it's calorie-free. However, certain health conditions can cause people to retain water, such as kidney disease, and drinking water may cause weight gain. If you think drinking water is causing you to gain weight, talk to your doctor.
Why You Need Water
More than half of your body weight is water, according to Clemson Cooperative Extension, and it's an essential part of every function your body performs. Healthy people need roughly 8 cups to 12 cups of water a day to prevent dehydration and for the body to function normally. This doesn't account for altered water needs due to weather, medications, exercise and diet, in which case more water may be necessary. While you can meet your daily water needs through a variety of different beverage choices and food, plain water is the preferred choice, reports Clemson.
Water and Weight Gain
While water is essential to life, certain groups of people need to limit their intake because drinking too much can lead to unintentional weight gain. This generally occurs in people with certain health conditions, such as congestive heart failure and end stage kidney disease. Swollen ankles are a sign of this type of weight gain, along with difficulty breathing and a lack of energy. Seek immediate medical attention if you're experiencing these symptoms.
Water and Weight Loss
Even though drinking water can lead to weight gain in certain people, it may help you lose weight if you're following a reduced-calorie diet. A 2008 study published in Obesity found that drinking 2 cups of water before each meal helped a group of obese people on a low-calorie diet lose more weight than a group following the same low-calorie diet without the water before each meal. The researchers noted that the water may have promoted weight loss by helping the participants feel full before they ate, so they consumed fewer calories.
If water is causing you to gain weight, talk to your doctor about how much water is safe for you to drink. Water, along with other fluids such as milk, coffee and soup, is generally limited to 2 quarts a day for those who need to restrict their intake, according to Brigham and Women's Hospital Outpatient Nutrition Department. If you're gaining weight and water has been ruled out as the cause, start tracking your caloric intake to determine if you're eating more calories than you need.