Many people feel hungry or crave snacks even after eating, but the real issue may be not drinking enough water. Family medicine physician Dr. Chen Hsin-Mei shared that in her clinical observations, many patients who believe they are “constantly hungry” are actually experiencing long-term dehydration. Warning signs include dark yellow or strong-smelling urine, dry lips, constipation, fatigue, and constantly wanting to eat despite not feeling truly hungry.
Dr. Chen explained on her Facebook page that the brain regions responsible for hunger and thirst are located very close to each other. When the body lacks water, the brain may misinterpret thirst as a need for energy, triggering cravings for food. Dehydration can also cause symptoms such as fatigue, poor concentration, headaches, dry mouth, and irritability.
She suggested a simple test when hunger strikes unexpectedly: drink 250–300 ml of water, wait 10 to 15 minutes, then reassess whether you are still hungry. Many people find that the urge to eat fades after rehydration. True hunger usually leads to a desire for a proper meal, while “false hunger” often triggers cravings for sweets, salty snacks, cold drinks, or junk food.
Dr. Chen also shared a guideline for daily water intake:
Body weight (kg) × 30–35 ml per day.
For example, a person weighing 50 kg should drink about 1,500–1,800 ml of water daily.
Signs of dehydration include dark urine, dry or cracked lips, dry skin, constipation, fatigue, headaches, difficulty concentrating, and frequent cravings without real hunger. Dr. Chen advised drinking water consistently throughout the day rather than waiting until feeling thirsty, as thirst is often already a sign of mild dehydration.
