What is the recommended daily intake of water for a healthy adult?

The recommended daily intake of water for a healthy adult is generally around 2 liters, or about eight 8-ounce glasses, often referred to as the "8x8" rule. This guideline is based on a variety of factors including average hydration needs, climate, activity levels, and overall health.

Staying adequately hydrated is vital for numerous bodily functions, including temperature regulation, joint lubrication, nutrient transport, and waste elimination. While this recommendation can vary based on individual circumstances, such as those who are physically active or live in hotter climates needing more fluids, the 2-liter guideline serves as a useful baseline for most adults.

It's also important to note that fluid intake can come from various sources, including beverages and food with high water content, which can contribute to overall hydration.