Don't wait until you're thirsty. Thirst is a late signal.
El cuerpo humano es, en su mayor parte, agua —y mantener ese equilibrio no es un lujo, sino la condición silenciosa de todo lo demás. Nutricionistas del Instituto Nacional de Salud del Perú recuerdan que la hidratación no llega solo del vaso, sino también del plato: seis a ocho vasos diarios, tres porciones de fruta y dos de verdura forman juntos el ritmo que sostiene la salud. Los niños y los adultos mayores, más vulnerables a perder ese equilibrio sin advertirlo, merecen atención especial. En un mundo que ofrece bebidas que deshidratan tanto como hidratan, la sabiduría más antigua sigue siendo la más útil: beber antes de tener sed.
- La deshidratación no siempre avisa: cuando aparece la sed, el cuerpo ya lleva tiempo en déficit.
- Los niños, absortos en el juego, y los adultos mayores, con sistemas de alerta internos menos eficientes, son los más expuestos a caer en deshidratación sin notarlo.
- El consumo de alcohol y bebidas energéticas con cafeína agrava el problema al tener efecto diurético, vaciando el cuerpo más rápido de lo que lo repone.
- La recomendación es concreta: al menos cuatro vasos de agua pura al día, complementados con jugos sin azúcar, infusiones, frutas de alto contenido hídrico como la sandía, y verduras como la lechuga o el pepino.
- Para quienes practican deporte o enfrentan calor intenso, la hidratación debe convertirse en una intervención planificada, no en una reacción tardía.
El cuerpo humano es aproximadamente un 60 por ciento agua. Cuando esa proporción cae, aunque sea levemente, el sistema empieza a fallar: la digestión se enlentece, la orina se oscurece, el estreñimiento aparece. Para los niños y los adultos mayores, el riesgo es mayor: los primeros están demasiado ocupados jugando como para notar la sed; los segundos han perdido parte de su capacidad de detectarla. En ambos casos, la deshidratación avanza sin que la persona lo advierta.
Nutricionistas del Instituto Nacional de Salud del Perú responden una y otra vez la misma pregunta: ¿cuánto hay que tomar? La respuesta es más sencilla de lo que parece, aunque exige repensar qué cuenta como hidratación. El cuerpo obtiene agua de dos fuentes: lo que bebemos —entre el 70 y el 80 por ciento del total— y lo que comemos, el 20 a 30 por ciento restante. Las frutas y verduras cumplen aquí un papel silencioso pero decisivo.
La recomendación base es de seis a ocho vasos diarios, de los cuales al menos cuatro deben ser agua pura. El resto puede ser té de hierbas o jugos naturales sin azúcar añadida. Pero hay un matiz fundamental: no hay que esperar a tener sed. La sed es una señal tardía. Hay que beber antes de que llegue.
A eso se suman tres porciones de fruta al día y dos de verduras. Sandía, melón, piña, papaya, fresa —frutas con alto contenido de agua que además aportan fibra y vitaminas. En el lado vegetal, lechuga, espinaca, pepino, tomate y acelga son opciones densas en agua. Una ensalada no es solo comida: es también una estrategia de hidratación.
Hay detalles prácticos que importan. El agua de caño debe hervirse o tratarse con dos gotas de lejía por litro antes de consumirse. Los deportistas deben planificar su hidratación antes, durante y después del ejercicio. Y conviene recordar que el alcohol y las bebidas energéticas tienen efecto diurético: en lugar de reponer agua, aceleran su pérdida. El objetivo es construir un ritmo constante a lo largo del día, adaptado a la edad, la actividad y la estación del año. El principio, sin embargo, no cambia: agua adentro, frutas y verduras adentro, y el cuerpo se mantiene en equilibrio.
Your body is roughly 60 percent water. Lose even a small fraction of that and the machinery starts to falter—your digestion slows, your urine darkens, constipation sets in. For children and older adults, the risk runs deeper. Kids are too busy playing to notice thirst. Elderly bodies have lost some of their internal alarm system. Both groups slip into dehydration without quite realizing it's happening.
Nutritionists at Peru's National Health Institute have been fielding the same question over and over: how much should I actually drink? The answer is simpler than most people think, though it requires a small shift in how you think about hydration itself. Your body takes in water two ways—through what you drink (about 70 to 80 percent of your daily intake) and through the food you eat (the remaining 20 to 30 percent). This second pathway is where fruits and vegetables do their quiet work.
The baseline recommendation is straightforward: six to eight glasses of water daily. Of those, at least four should be plain water. The others can be herbal tea, fresh juice without added sugar, or other unsweetened beverages. But here's the catch that catches most people: don't wait until you're thirsty. Thirst is a late signal. By the time you feel it, your body is already running a deficit. Drink before the signal arrives.
For children, the stakes feel higher because they are higher. Luis Aguilar, a nutritionist at the institute, explains that kids have a higher proportion of water in their bodies than adults do, yet they're less likely to recognize when they need it. They're absorbed in play, in movement, in the moment—and dehydration creeps in unnoticed. Older adults face a different problem: their bodies simply don't regulate water as efficiently. Dehydration in this group manifests as constipation, sluggish digestion, concentrated urine, and a cascade of other complications that can spiral quickly.
Beyond water itself, the institute recommends three portions of fruit daily and two of vegetables. Watermelon, cantaloupe, pineapple, papaya, mandarin oranges, strawberries—these are your high-water fruits, the ones that deliver hydration wrapped in fiber and vitamins. On the vegetable side, lettuce, spinach, cucumber, tomato, and Swiss chard are water-dense choices. A salad isn't just food; it's a hydration strategy.
There are practical details worth noting. If you're drinking tap water, make it safe first: boil it or add two drops of bleach per liter and let it sit for thirty minutes. If you're an athlete, the rules shift. Before exercise, during it, and after—hydration becomes a planned intervention, not an afterthought. A sports nutritionist can help you time it right.
One more thing: watch what you're drinking alongside the water. Alcohol and energy drinks high in caffeine have a diuretic effect—they make your body shed water faster than you're taking it in. They work against you. The goal is to build a rhythm of steady, consistent hydration throughout the day, one that accounts for your age, your activity level, and the season. Summer heat accelerates dehydration. So does a sedentary day followed by sudden exertion. The body's needs aren't static. But the principle is: water in, fruits and vegetables in, and the body stays balanced.
Notable Quotes
Children should maintain adequate hydration because they are more active, have lower thirst perception when distracted, and have a higher proportion of water in their bodies compared to adults.— Luis Aguilar, nutritionist at Peru's National Health Institute
The Hearth Conversation Another angle on the story
Why does the institute single out children and elderly people as especially vulnerable?
Because their bodies have lost or haven't yet developed the internal mechanisms that keep hydration in balance. A child's body is mostly water, but they don't feel thirst the way adults do—they're too distracted. An older person's thirst mechanism has dulled with age. Both groups can slip into dehydration without realizing it until the damage shows up as constipation or worse.
So the six to eight glasses a day—is that a hard rule, or does it change?
It's a baseline. The real number depends on how active you are, how hot it is, whether you're exercising. But six to eight is where most people should start. The key insight is that at least four of those should be plain water. The rest can come from tea or juice, but plain water is the most direct route.
You mention that 20 to 30 percent of hydration comes from food. That seems like a lot to leave to chance.
It's not chance if you're intentional about it. A plate of salad with lettuce and tomato, a slice of watermelon—these aren't luxuries. They're part of your hydration strategy. The water in food comes with fiber and nutrients, so you're not just hydrating; you're nourishing.
What about the warning on alcohol and energy drinks?
They work against you. They make your kidneys shed water faster than you're taking it in. If you're already in a hot climate or you're active, adding those to your day is like trying to fill a bucket with a hole in the bottom.
Does timing matter? Should you drink all your water at once?
Spread it throughout the day. Your body can only absorb so much at once. Steady, consistent intake is what keeps the system running smoothly. And don't wait until you're thirsty—that's already late.