How Much Water Should You Really Drink? 7 Evidence-Based Answers on Amount, Timing, and Season

This article provides a comprehensive evidence-based examination of daily water requirements across five dimensions that most hydration guides neglect: body composition, personalised quantity, timing, seasonal variation, and over-hydration risk. The body composition analysis documents organ-specific water percentages that make hydration physiologically meaningful: lungs 83%, brain and heart 73%, kidneys and muscles 79%, skin 64%, and bone 31%, with total body water averaging 60% in adult men and 55% in adult women, declining with age and adiposity. The personalised formula of 30-35 ml per kilogram of body weight is compared against EFSA, WHO, and National Academy of Sciences recommendations, with adjustment factors for exercise, climate, diet, and health status. Ayurvedic hydration science including Jala as one of the Panchamahabhuta, Ushna Jala as documented in Ashtanga Hridaya by Vagbhata in the 7th century CE, Ashtamukha Jala, seasonal water protocols from Ritucharya, and the clay pot tradition is integrated with modern evidence from the American Journal of Gastroenterology and gastrointestinal physiology research. The debunking of the 8x8 myth and clinical evidence on hyponatremia, including the 2002 Boston Marathon study where 13% of finishers had dangerously low blood sodium from excessive plain water, complete the evidence framework.