Do We Need 8 Glasses of Water a Day?

Posted By Integrated Medical Center of Florida on Nov 16, 2016 |


Do you know where the idea of drinking eight glasses of water per day came from? Neither does anyone else.

Yet many nutritionists, weight-loss experts and general health gurus claim we must drink that much every day.

I certainly tried to do it. I would drink coffee in the morning, then maybe force down a glass of water. By the time I had sweet tea with lunch, I was not thirsty but would try to choke down two more glasses of water in the afternoon.

By the time I had a glass of wine and more tea for supper, I was full – and facing five more glasses of water! I just could not do it day in and day out.

I know many of you can, and I’m proud of you. But for the rest of us who wallow in guilt, there is good news.

Before I get to that, let me reinforce the necessity of good hydration. Drinking water in adequate amounts is necessary for maintaining the organ systems. In a resting state, this is easy and can be done in many ways. But in times of vigorous physical activity or in high temperatures, consumption must be increased and maintained to keep the body’s core temperature from rising dangerously and to prevent dehydration.

Yet research has shown recently that there is no supporting evidence to back the popular notion that eight glasses of water a day is essential to good health. Studies have been duplicated where normal adults of both genders were compared, showing no difference in hydration status.

We are not walking around in a dehydrated state as some would have us believe.

We should drink water when thirsty. It’s still the best indicator, and this signal is delivered from our brains when we have lost between 1 percent and 2 percent of our body’s water. This amount is not dangerous.

Scientific studies also prove that there is no extra benefit to the skin by drinking more water. Nor is there supporting evidence that it significantly curbs appetite.

Nature intended for us to obtain much of our water from the food we eat. Fruits and vegetables are 80 percent to 90 percent water. Meat contains a fair amount, and even dry bread and cheese are about 35 percent water.

Caffeinated beverages such as coffee, tea and soda do not necessarily contribute to dehydration. Caffeine does cause a loss of water, but only a fraction of what you are adding by drinking the beverage itself.

If you like to drink eight glass of water a day, that’s fine. But don’t feel guilty if you choose not to walk around with a bottle like everyone else. Instead, eat balanced meals and follow your thirst mechanism.