Have you ever eaten a full lunch, yet found yourself reaching for snacks in the afternoon—especially craving desserts or sugary drinks? Family medicine physician Dr. Chen Hsin-Mei explains that in many cases, this isn’t true hunger at all, but a sign that the body is dehydrated. By simply drinking a glass of water and waiting 10 minutes, you may be able to tell whether you’re genuinely hungry—and even stop those afternoon dessert cravings altogether.
Dr. Chen explains that the areas of the brain responsible for thirst and hunger are located very close to each other. When the body lacks water, the brain can misinterpret thirst signals as a need for energy. Studies have also found that the neural circuits involved in food-seeking behavior become activated during dehydration. This is why afternoon cravings tend to be for sweets, snacks, or cold drinks rather than a proper meal.
In simple terms, the body is asking for water, but the brain mistakenly tells you that you’re hungry.
When sudden cravings hit, Dr. Chen recommends drinking 250 to 300 milliliters of plain water first, then waiting about 10 minutes before deciding whether to eat. Many people find that the urge to snack gradually fades. True hunger usually comes with a desire for a full meal, while “false hunger” often shows up as cravings for sweets, snacks, or iced beverages.
So how much water should you drink each day? Dr. Chen offers an easy formula: 30 to 35 milliliters of water per kilogram of body weight. For example, a person weighing 50 kilograms should aim for about 1,500 to 1,800 milliliters of water daily. There’s no need to drink it all at once—spreading water intake throughout the day is more effective. Drinking water after waking up, during work hours in the morning and afternoon, and about 30 minutes before meals can significantly reduce unnecessary cravings.
