Can Drinking Water Really Help Lose Weight ?

Body Mass Index (BMI) is commonly used to determine weight problems in adult. It’s calculated by dividing weight in kilogram by height square in meters (weight (kg)/ [height (m)]2). For adults above or equal to 20 years of age, normal BMI values lies between 18.5 to 24.9. Athletes with muscle mass may normally have values higher than 24.9(1).

There are so many ways to lose weight that one can write an encyclopedia on it. One way is to drink sufficient water. Be aware that too much water could lead to electrolyte problems in the body (2). The Institute of Medicine advises that healthy men consume roughly 3.7 liters of total water (from all beverages and food) a day and healthy women consume 2.7 liters of total water a day (3).

How Drinking Water Helps Lose Weight?

1. Drinking plain water increases energy expenditure and rate of fat breakdown (4).
2. Replacing caloric beverages with drinking water lowers total energy intake by eliminating beverage calories (5).

Weight Loss Study

In a study, drinking approx 1 liter of plain water over 12 months caused 5 lb weight loss(6). Experiment has shown that 500 ml of drinking water leads to 100 kJ of energy loss (7). So 1 liter/day for 365 days would lead to 73000 kJ (2 x 100 x 365) of energy loss. 1 dietary calorie is equal to 4.2 kJ. Therefore, 73000 kJ would be equal to 17380.95 Calorie (73000/4.2). 1 gm of fat is equal to 9 dietary calories. So, 17380.95 dietary calories translates to 1931.21 gm (17380.95/9) of fat. This is approx 2kg or 5 lb of fat. In this study, weight loss effect of diet, and changes in other beverage intake, the amount and composition of foods consumed and physical activity were controlled. Thus, drinking plain water helps lose weight independent of all other ways of weight loss.


1. Healthy Weight – it’s not a diet, it’s a lifestyle! Updated August 17, 2011. Accessed September 04, 2011.
2. Lorraine-Lichtenstein E, Albert J, Hjelmqvist H.[Water is a dangerous poison... Two cases of hyponatremia associated with spinning and extensive fluid intake].Lakartidningen. 2008 May 28-Jun 3;105(22):1650-2.
3. Consensus Report:Dietary Reference Intakes: Water, Potassium, Sodium, Chloride, and Sulfate. Released:February 11, 2004
4. Keller U, Szinnai G, Bilz S, Berneis K. Effects of changes in hydration on protein, glucose and lipid metabolism in man: impact on health. Eur J Clin Nutr 2003;57(Suppl 2):S69–S74.
5. DellaValle DM, Roe LS, Rolls BJ. Does the consumption of caloric and non-caloric beverages with a meal affect energy intake? Appetite 2005;44:187–193
6. Stookey JD, Constant F, Popkin BM, Gardner CD.Drinking water is associated with weight loss in overweight dieting women independent of diet and activity.Obesity (Silver Spring). 2008 Nov;16(11):2481-8.

Last Updated: Sep 4,2011

Similar Health Articles: