Even mild dehydration can alter a person's mood, energy level, and ability to think clearly, leaving them 'cranky' and tired, say researchers.
According to the study, published in the British Journal of Nutrition, even before we become thirsty, mild hydration could be enough to alter our mood and energy levels.
The study, led by Professor Lawrence Armstrong of the University of Connecticut, USA, revealed that the adverse effects from mild hydration, which is defined as 1.5% loss in normal water volume, were the same whether people were sitting at rest or active.
Professor Armstrong said the results assert the importance of staying properly hydrated at all times, and not just during exercise, extreme heat or exertion.
"Our thirst sensation doesn't really appear until we are 1 or 2 percent dehydrated. By then dehydration is already setting in and starting to impact how our mind and body perform".
"Dehydration affects all people, and staying properly hydrated is just as important for those who work all day at a computer as it is for marathon runners, who can lose up to 8 percent of their body weight as water when they compete", he affirmed.
Dr Harris Lieberman, a co-author of the research explained "Even mild hydration that can occur during the course of our ordinary daily activities can degrade how we are feeling - especially for women, who appear to be more susceptible to the adverse effects of low levels of dehydration than men".