Dieters are often told - drink water. Drink a minimum of 64 ounces a day - eight glasses a day. Gastric-bypass patients don't have a choice: they must drink lots water. Other beverages including coffee, tea, milk, soft drinks and alcohol are forbidden. Water is the essential fluid for living. Water is one of the most important nutrients the body needs to stay healthy, vibrant and energetic. A tell-tell sign of a gastric bypass patient is the ever-present water bottle.

The restrictive and malabsorptive nature of the gastric bypass causes several things to go wrong if a patient partakes of caffeine coffee or tea, high-caloric or alcoholic beverages. The caffeine assimilates into the blood stream very quickly causing jitters and nervousness more-so than a normal digestive system. The high-caloric beverages are easily absorbed through the shortened intestine causing a weight plateau or weight gain. And alcohol is absorbed with break-neck speed causing intoxication, vomiting or dumping.

Knowing this bariatric centers advise patients to drink water throughout the day to avoid dehydration. However, patients are told to avoid drinking water with meals as it will facilitate food movement through the small stomach pouch allowing a person to consume more food.

Nutritionists say a precise measure of the body's need for water is to divide body weight (pounds) in half and drink that many ounces every day. That number could well exceed 200 ounces a day for morbidly obese people actively engaged in weight loss. Most doctors advise gastric bypass patients to consume 64 to 72 ounces of water daily.