Water weight loss is a temporary reduction in body weight due to the loss of bodily fluids -- generally through sweat, urination or defecation. The body is as much as 60 percent water, which is present in the blood and lymph fluids and absorbed into the tissues. When the tissues absorb this water, they become heavier, the same way a waterlogged cloth is heavier than one that is slightly damp. When the tissues lose this water, they become lighter.
Several factors trigger your body to lose more water than normal. Diuretics stimulate the kidneys to draw more water into the urine while laxatives cause the intestines to draw more water into the feces, both of which can cause water weight loss. Thermal suits, body wraps and saunas all encourage excessive sweating, which can also cause water weight loss. Certain fad diets trigger the body to use more water for metabolic processes, which triggers more waste removal and water weight loss. Illnesses that cause vomiting, frequent urination or diarrhea will also cause water weight loss.
Water weight loss may cause a drop of several pounds of body weight in a very short time -- as little as one day -- but the effect is always temporary. The moment you consume liquids, your body reabsorbs the water. The only way to avoid regaining water weight is to continually do things that are dangerous to your health, such as constant laxative use or cutting your fluid consumption.
Water weight loss can be dangerous and life threatening because it can cause dehydration. When your body becomes dehydrated, it does not have enough water for basic metabolic processes. In mild cases, your body may take any water it does get and retain it in the tissues, which can lead to bloating. Additionally, your body may not burn fat as efficiently, and you may actually gain weight over time. In severe cases, your body will pull water from the blood, which makes the blood thicker and can lead to a dangerous drop in blood pressure.
While water weight loss may seem tempting, there are healthier and longer-lasting ways to lose weight. Additionally, staying properly hydrated will actually help you lose weight more efficiently, according to CNN diet and fitness expert Dr. Melina Jampolis. The best way to lose weight is with a combination of a healthy diet, rich in water-containing fresh fruits and vegetables, and daily exercise.
- Personal Trainer Manual; American Council on Exercise; December 1996
- Physiology of Sport and Exercise; Dr. Jack H. Wilmore, et al; November 2007
- National Center for Biotechnology Information: Dehydration
- CNN: Can Drinking Lots of Water Help You Lose Weight?