The medium every reaction inside you happens in.
Water
Every enzyme, every nutrient, every waste product moves through water. Thirst is a late signal — by the time you feel it, you've been dry for a while. Steady sips beat gulping.
Food is a major source of water too. Fruits, vegetables, soups, and stews all contribute. A day of dry foods and low fluids feels different from a day with fruit and soup.
Something to investigate
Do you drink most of your water before, during, or after meals? Different traditions favor different timing — worth trying both.