Many people drink water only when thirsty or limit intake for weight loss. This habit harms the digestive system, according to Doctor Ho Thi Ha Phuong of Tam Anh Cau Giay General Clinic. The human body is composed of about 60% to 70% water, and the digestive system requires sufficient fluids for normal function. Water aids in saliva production, gastric fluid secretion, protection of the stomach lining, and supports food digestion and absorption. Insufficient water reduces saliva, making oral digestion less effective and increasing the stomach's contractile pressure.

The stomach lining is covered by a mucus layer that acts as a biological barrier, protecting the stomach from the corrosive effects of gastric acid. The production of this mucus layer depends on the body's water content. Chronic dehydration can weaken this protective layer, causing the lining to become irritated by acid. This irritation can lead to a burning sensation in the epigastric region (above the navel), bloating, or a dull ache after meals.

Drinking plain water helps produce saliva and supports food digestion. Illustration: AI

Water also maintains the fluidity of digestive juices, ensuring stable circulation. When the body is dehydrated, gastric fluids become more concentrated, intensifying feelings of an empty stomach or discomfort for sensitive individuals, or those with stomach ulcers or gastroesophageal reflux.

According to Doctor Phuong, insufficient water intake is a common cause of constipation. Dehydration forces the large intestine to absorb more water from stool to maintain fluid balance, making the stool dry, hard, and difficult to pass.

Doctor Phuong recommends that adults maintain an intake of about 1,5 to 2 liters of water daily, depending on their physical condition, activity level, and environmental factors. Office workers who use air conditioning continuously often experience water loss without a clear sensation of thirst. The elderly also have a slower thirst reflex than normal, making them prone to prolonged dehydration; they need to supplement more water to support stable bodily functions.

Individuals working outdoors, athletes, or those in high-temperature environments should drink more than 2 liters of water daily to compensate for fluid loss through sweat. It is advisable to drink water regularly throughout the day, in small, frequent sips, for better absorption and to avoid overwhelming the stomach.

Maintain a habit of drinking water at specific times, such as: upon waking, about 30 minutes before meals, and increasing intake during physical activity or hot weather. Prioritize plain water and limit sugary sodas, milk tea, and caffeinated beverages.

Thanh Ba