Dr Kavouras on hydration: “Adopting healthy habits early on can go a long way.”


Following the 6th Hydration for Health Conference, Dr Stavros Kavouras tells us why hydration matters and explains the specificities of hydration in children.


The 6th Hydration for Health (H4H) scientific conference was held in Evian, France on  July 3. It involved experts on hydration and its effects on health, and highlighted the importance of appropriate fluid intake at an early age. Dr Stavros Kavouras is an Associate Professor at the University of Arkansas, an expert in the field of hydration and its effects on health and exercise performance, and a member of the Danone Hydration Scientific Advisory Board. He addressed the subject of hydration in childhood during the H4H Conference. We took the opportunity to ask him a few questions about hydration and how it impacts children’s health long term.

This was the 6th Hydration for Health (H4H) scientific conference. Why is this conference important?

H4H is unique because it is one of very few conferences fully focused on the effects of hydration on health. It also gets better and better with each edition. Hydration is absolutely vital to health and longevity and it plays a key role in overall health, kidney health and cardiovascular diseases, but the topic has not attracted enough attention over the past 30 or 40 years. That said, in the past three or four years, momentum on hydration has been building. There is more and more data in the literature. Water is a key macronutrient, the most important one, and it is starting to get the recognition it deserves.

During the conference, water was described as the “forgotten nutrient”. Could you explain?

Over the past three to four decades, large epidemiological studies (on cardiovascular diseases and cancer, for instance) would precisely record all nutrients except water. There is no data on water. I’m not sure why people tend to forget it, maybe because water doesn’t provide calories. I often draw the parallel with the scientific literature on smoking. Back in the 1970s, even medical doctors would describe smoking as cool and harmless, and it has taken decades of intense research and tremendous amounts of funding to establish how smoking impairs health. To some extent, water-related literature has been quite like literature on smoking was in the 1970s. But it is catching up very fast.

Can you describe what we know so far in terms of drinking habits in children?

Several sets of data, accumulated during the past four to five years, indicate that children tend to under-drink. This is what we refer to as “involuntary dehydration ».

A significant percentage of children can generally be described as “low-volume drinkers,” i.e. as people who are not drinking enough and run on the low side in terms of hydration.This means that their bodies are constantly fighting dehydration.

Kidneys are the first organs to respond to hypohydration: they work overtime, and as a result the children’s urine is very concentrated and dark.

This has long-term implications. Back in the 1990s, when I was in graduate school, it was generally thought that childhood obesity was not a health problem, that obesity only became a health problem if it continued into adulthood. But children, even at an early age, can in fact develop all sorts of chronic diseases (obesity, diabetes and cardiovascular diseases). There is some evidence that insufficient drinking has long-term health consequences in adults; we are now working on collecting data to see if this also applies to kids.

Why should we look at fluid intake in children? Do they have specific needs?

Children do have specificities.

When they are physically active, they tend to forget their own thirst, and even the need to go the bathroom! When they are having fun, they just forget.

Another important element is that a lot of nutritional choices we make as adults are the result of habits formed during childhood. It is important to build healthy habits early on, it can go a long way.

What can we do in our daily lives to check our hydration status?

Hydration can change significantly from one day to the next. It is thus important to have simple tools to assess our own hydration state daily. The simplest thing, something anybody can do, is to look at urine colour. The darker the colour, the more concentrated, which indicates that your body is fighting dehydration. There are other indicators, such as the number of visits to the bathroom. We are working on more specific guidelines for that. But overall, urine colour is the best single practical tool available that everybody can use. It is simple, and it is free.

You have worked on a urine colour scale designed specifically for children. What were the challenges in developing it?

The urine colour scale was published 20 years ago by Professor Larry Armstrong, and it was targeted at adults and athletes. With children, while the science fundamentally applies*, the specific challenge was to make sure the message really got through. The Urine Colour Scale had to be fun and it had to speak to kids. We also wanted it to be international, which meant no words. The design for kids was extensively tested and we have strong feedback that the children understood it. Two years ago, we put together an educational programme for children, where we put this urine colour scale in the bathroom and talked to them about hydration. We saw that they drank more, improved their hydration state and their exercise performance got better in just one day**. They see it as a game, and so it works.

Photo © umbertoleporini


*Arnaoutis G, Bougatsas D, Panagiotakos DB, Ganio MS, Kavouras SA (2013). Validation of urine color scale in kids. Med Sci Sports Exerc 45(5S):343


Kavouras SA, Arnaoutis G, Makrillos M, Garagouni C, Nikolaou E, Chira O, Ellinikaki E, Sidossis LS. Educational intervention on water intake improves hydration status and enhances exercise performance in athletic youth Scand J Med Sci Sports. 2011; 2012: 22: 684–689