1% level of dehydration is said to correlate with a 5% decrease in cognitive function (e.g., fuzzy thinking, math confusion, forgetfulness, and lack of ability to focus). Some of the cognitive malfunction may result from shrinkage of brain tissue (e.g., as dehydration sets in, brain tissue begins to pull away from the skull), a potential contributor to the development of dementia. Losing only 1-2% of your body’s water weight can result in weakness and fatigue. The movement of water in and out of the cells functions much like a hydroelectric plant to create energy. When water levels fall, the production of energy also falls. Losing 10% of your body’s water can lead to life-threatening heat stroke. Fruit juices, sodas, soft drinks, and other sugary beverages promote dehydration—as the body uses water to process them. Ethanol (alcohol) depresses the level of anti-diuretic hormone, increasing urine volume to the extent where more fluid is lost in urine than is gained in the drink. More tomorrow.