Medical questions & health advice by board certified doctors

"What does it mean to lose water weight?"

ZocdocAnswersWhat does it mean to lose water weight?


I'm on my college wrestling team and have to lose weight fast. My friend said its okay to go on a crash diet where I don't eat because I'll lose water weight. What does that mean? Is it safe to lose water weight fast?


All carbs are converted to glucose. Excess glucose is then converted to glycogen. Glycogen is a normal part of metabolism that allows us to draw on the carbs stored in our muscles for energy as well as it allows us to keep our brain functioning. Glycogen maintains the majority of its weight in water like a sponge. When you eliminate the carbs or maintain a low carb consumption through a crash diet, you deplete the "emergency" stores of carbohydrate your body keeps in liver and muscles in the form of glycogen. After a week of crash diet, new dieters are excited to lose up to 5-10 lbs, depending on how big their glycogen stores are. It looks dramatic, but it is just water weight. After such instant weight loss, it slows down to normal levels- 3 to 8 lbs a month. If you slip up during your first week of crash dieting and eat a "normal diet" for just a day, you will gain the lost pounds back, all 5-10 lbs of them. These quick losses and gains are almost entirely water. You haven't lost fat. You've simply dumped the water out of your liver and muscles. It is short-term and can be unsafe. To lose weight effectively, obviously you have to eat fewer calories than your body uses or burn off the excess calories by exercising or just being active. You can lose 1 lb of fat a week. Many experts would advise you not to lose more than 2 lbs a week because it means that you lose water weight and thus fail in the long run. I would recommend that you consult with a primary care physician who can examine you physically and devise an appropriate diet regimen so that you can lose weight effectively.

Zocdoc Answers is for general informational purposes only and is not a substitute for professional medical advice. If you think you may have a medical emergency, call your doctor (in the United States) 911 immediately. Always seek the advice of your doctor before starting or changing treatment. Medical professionals who provide responses to health-related questions are intended third party beneficiaries with certain rights under Zocdoc’s Terms of Service.