We’ve all heard the “8 glasses a day” rule. But when it comes to water consumption, many adults—and the vast majority of older Americans—aren’t drinking enough, finds a 5-year study from French and American researchers.
The study team evaluated overall H2O consumption among more than 15,000 Americans. Those numbers included drinking water, but also H2O from other beverages and foods. Among adults aged 20 to 50, 43% of men and 41% of women failed to meet the daily water intakes recommended by the US Institute of Medicine (IOM) (about 6 pints for women and 8 pints for men). People aged 50 to 70 were even less likely to meet the guidelines, and the numbers tanked among older adults; roughly 95% of men and 83% of women 71 and older don’t drink enough water, the research shows.
Here’s why all this matters: Consume too little H2O, and your body will struggle with countless functions ranging from joint lubrication, to digestion, to temperature regulation, according to the Centers for Disease Control and Prevention. Drinking water can also combat fatigue and help you lose weight, studies show.
So how much water do you really need? The IOM recommendations are a good starting point, says study coauthor Adam Drewnowski, PhD, of the University of Washington. But those requirements are simple targets, the study authors stress. If you live in a hot or humid climate, or you take part in sweaty activities like running or tennis, you need to drink even more.
And no, you can’t rely on your sense of thirst to tell you if you’ve had enough water, Drewnowski warns. Citing research from Johns Hopkins University, he says the sensation of being thirsty fades as adults age—regardless of water intake—which might be one reason older adults don’t drink enough. Bored with plain old water? Try one of these 25 Flat Belly Sassy Water recipes to add flavor without chemicals or calories.