Lack of water is the number one trigger of daytime fatigue. . A mere 2% drop in body water can trigger fuzzy short-term memeory, trouble with basic math, and difficulty focusing on the computer screen. Filtered or distilled water is better than tap water.
Even mild dehydration will slow down a person's metabolism as much as three percent. Drink your water. One glass of water shuts down might hunger for 100% of the dieters studied in a University of Washington study.