As long as no added syrup or sugar, white water (H2O) is a compound free of calories. Even taken together with food, water will not provide extra calories so it will not cause obesity.
Not only that, drinking water actually causes the stomach feel full faster. Quoted from MSN Health, Wednesday (08/04/2010), this causes decreased appetite, thus avoiding the possibility of eating excessive portions.
This theory was proven in a study published in the journal Obesity in the year 2007. In people aged 55 years and over, the habit of drinking 0.5 liters of water before meals can reduce weight by 44 percent within 12 weeks.
Another study said, the white water can increase thermogenesis or metabolism of calories into energy. No matter before or after eating, drinking 0.5 liters of room temperature effective to increase metabolism by 30 percent in the first 10-30 minutes afterward.
Related to this, speculation has developed the experts is that the body becomes more energy needed to raise the temperature of the water they drink at room temperature to conform to the body temperature. In adults, this process takes an average of 29 calories of energy.
As for the digestive system, there is no scientific evidence that water can trigger the disorder. In the process break down food into nutrients that can be absorbed by the body, the presence of water in the digestive tract it will help.
Water as a medium to dissolve some components of dietary nutrients, and thus more easily absorbed by the intestinal wall. Origin balanced with proper diet, drinking water while eating it either to lose weight.[detik.com]