A New York Times article published has sparked a debate on how much water is actually needed for a day. The piece challenges the 8-glasses-a-day habit and urges readers to forget about aiming for the 64 ounces and just listen to their body. Put forther by Dr. Aaron Carroll, he works through to debunk the eight cups a day theory, even calling it a myth. Other health professionals have spoken out against this as well, significantly from a doctor in the British Medical Journal from 2011.
He compares this theory to eating five servings of fruits and veggies per day or getting eight hours of sleep. These are statistics so central to leading a healthy lifestyle that we don't question it any more. But apparently it's not actually backed by science. And believe it or not, forcing yourself to drink water when you're not thirsty may do more harm than good.
So why has the eight cups a day method been touted for so long? It's partly due to misinformation that made its way through to doctors and experts. Carroll also suggests that many people want to believe that drinking more water is a cure-all for weight loss and other ailments.
Another commonly circulated, easy-to-believe myth: If you’re thirsty, you’re already dehydrated — Carroll says there’s “no science behind this at all.” In extreme cases, drinking too much water can lead to seizures or other serious issues.
Food gives most people the hydration they need over the course of the day. There's water in everything: fruits, vegetables, and almost every beverage we drink. There's no rational need and no scientific need for 64 ounces of pure water per day, says Carroll.
Now, of course, there are situations in which patients are actually hydrated. This is mostly a cause of diarrhea, vomiting and other inabilities to keep liquids down. If you suspect you may be hydrated, contact your doctor.
Carroll says there’s no magic number of glasses of water you should drink per day — just trust your body. “When you’re thirsty, you’re way far away from dehydration,” he says. “Just drink when you’re thirsty.”