Cork City GP Dr. Doireann O'Leary joined Brendan O'Connor on RTÉ Radio 1 to warn listeners of the dangers of over-hydrating - listen back.
Social media users have been taking to TikTok and YouTube to share the results of their '30 Day Gallon Challenge'.
As the name suggests, the objective of the viral tend is to drink a gallon (4.5 litres) of water every day for 30 consecutive days, with users claiming that it has resulted in everything from weight loss to clearer skin.
But is this craze all it's cracked up to be?
Dr. Doireann O'Leary told Brendan that, while being properly hydrated is very important, too much water is potentially bad for our health.
"If we're dehydrated, it reduces our concentration ability, our cognitive ability, our performance in terms of work and in exercise. Being optimally hydrated - or drinking enough water - obviously is important but, similarly, we can go too far and become too obsessive about it.
"Drinking a gallon a day, I would say, is too much."
Dr. O'Leary explained that if someone was to drink three liters of water within an hour, it would be more than the kidneys could handle and cause a "dilutional effect", which would essentially increase the blood volume without increasing your red blood cell count.
This could potentially lead to hyponatremia, whereby sodium levels dip below a normal range, which can lead to symptoms including nausea, vomiting, fatigue, headache, cramps, irritability, and weakness.
Moving away from the extremes of the gallon challenge, Dr. O'Leary said that a good ballpark figure to aim for is about eight glasses or two and a half liters of water a day, although she notes that the recommendation included non-liquids.
"Liquids make up about 70% of our water intake and then foods make up the remainder, so remember you are actually getting water in, and making up a part of your two and a half liter target, if you like, from things like fruit, soup, stew, yoghurt," she explains.
To hear Dr. O'Leary's full chat with Brendan O'Connor in full, listen back above.
