When we consume a lot of salty foods at once, our brains will secrete ADH, which in turn tells our kidneys to retain water, preventing us from urinating excess fluid. At the same time, the brain secretes another hormone, vasopressin, which is linked to feelings of thirst. Together, all these hormones indicate that you need more fluids. Consuming too much salty food is only a problem if you also ignore your thirst quenching, said Dr. Hew Butler.
If you’re looking for savory foods that are moisturizing, olives and pickles are acceptable choices, although it is rare that people consume them in large quantities. Soup, especially with water-based stock, can also help you fill up with water.
But what is actually dehydrating is alcohol. “Alcohol suppresses ADH,” said Dr. Hyndman. So when you consume it, “you don’t have this hormone that tells your kidney to reabsorb water” and all the fluids you consume will go right through you.
Make sure that children, the elderly and people with medical needs can enjoy themselves
“Most of us who say we’re dehydrated probably aren’t,” said Dr. Hyndman. While there are probably people who walk around a little dehydrated, she added, the majority of people are adequately hydrated or even a little overhydrated. If you’re complaining about a small bladder, or if you’re just urinating more often than you’d like, you may not need to take in as much fluid—it just flows through you.
Those who should be most diligent about actively hydrating are children, older adults and people with underlying medical conditions, said Dr. Hyndman.
The rest of us just need to drink or eat foods that are full of fluids when we’re thirsty, said Dr. Hew-Butler, and trusting our instincts. “We don’t have to think about it,” she added.
“I think the ‘drink when you’re thirsty’ rule is hard to fight,” said Dr. Negoianu, excluding medical conditions or extremely harsh environments that can cause abnormal water loss. “When it comes to the amount of water you need, it’s like Goldilocks and the three bears.” Just as Goldilocks had to decide for themselves which porridge was just right, everyone needs to find the hydration level that’s just right for them and their situation.