Water is vital for many functions in your body, including metabolism. It's also essential for transporting nutrients and oxygen, helping to boost energy so you can put maximum effort into your workouts. And it can help to suppress your appetite, thereby helping to prevent you from overeating. But guzzling copious amounts of water can backfire and inhibit weight loss, especially if you're not eating a balanced diet and not getting enough exercise.
Drinking too much water isn't likely to lead to weight gain that you won't lose within a day or two.
Is it Water Retention?
Occasionally, those extra pounds are partly "water weight." If you drink a lot of water in one sitting — as opposed to over the course of a day — your kidneys may not be able to keep up and expel the excess water. Excess fluid in your body may disrupt the balance of electrolytes in your body that are responsible for regulating water. Furthermore, if your diet is high in sodium and low in potassium, you are more at risk for retaining water.
Pollutants and Weight Gain
Drinking more water can increase your exposure to pollutants as well, particularly if the water is not filtered or purified. And in a study published in the journal Obesity in 2011, Belgian researchers also found that some persistent organic pollutants were significantly linked to body mass index, fat mass and subcutaneous and abdominal fat.
A more recent review article published in Current Diabetes Reports in 2017 found results that were similar to the findings of the 2011 study. However, the article also suggested that more research was needed to better understand the relationship between weight gain and pollutants.
Complications of Too Much Water
Not losing weight pales in comparison to another consequence of drinking too much water — hyponatremia. This condition may occur when you drink a large volume of water in a short period of time. It causes your blood and electrolytes to become diluted and can lead to health problems such as nausea, vomiting, confusion, muscle spasms, seizures and swelling of the brain.
Hyponatremia is a rare condition and primarily affects marathon runners or triathletes, but that doesn't mean you're not at risk. Without immediate medical attention, hyponatremia can be fatal.
Amount to Drink Daily
There's no fixed amount of water to drink. The amount you need depends on a variety of factors such as your weight, activity level, environment — for instance, hot and humid versus cold — and your natural rate of perspiration. Even pregnancy affects your water needs.
While there is debate about whether you should use thirst as an indicator of when to drink water, the National Academies says you can and also recommends 91 ounces of total water from all beverages and food for women and 125 ounces for men daily. A nutritionist or dietitian can help you determine more specific amounts to meet your needs.
- Dartmouth Medical School: Drink at Least 8 Glasses of Water a Day - Really?; Aug. 8, 2002
- Obesity: Obesity and Persistent Organic Pollutants: Possible Obesogenic Effect Of Organochlorine Pesticides and Polychlorinated Biphenyls
- Current Diabetes Reports: Persistent Organic Pollutants as Risk Factors for Obesity and Diabetes
- National Academies: Dietary Reference Intakes: Water, Potassium, Sodium, Chloride and Sulfate