Abstract
Water is considered the single most important nutrient, yet receives relatively little attention from nutritional experts. This is likely due to the fortunate fact that finely-tuned physiological mechanisms ensure adequate intake in the vast majority of individuals. Accordingly, some even question whether the standard “8 daily glasses” are necessary. Moreover, water is a major constituent of food, comprising up to ~95% of the weight of some common plant-based foods; thus, consuming a diet rich in fruits, vegetables, and dairy will inadvertently increase water intake. An added benefit of consuming more water in food is the increased satiation for lower caloric density which facilitates weight loss and maintenance. While most healthy individuals adequately fulfill their hydration needs through the physiological thirst response, some special populations including the very young, very old, and athletes, do deserve special consideration. With the increased incentive for Americans to increase their physical activity, and the increased prevalence of recreational athletes entering endurance athletic events, comes increased impetus to educate all individuals on the importance of proper hydration during exercise training. Most athletes, both professional and recreational, do not obtain adequate hydration to match sweat losses, while some novice endurance athletes over-hydrate placing them at risk for hyponatremia, a potentially life-threatening condition. In general, increasing the consumption of water-rich foods, replacing most caloric beverages with water, and learning about personal hydration needs is sound nutritional advice for everyone to follow.