Which nutrient is considered the most indispensable and constitutes 60-70% of body weight?

Water is considered the most indispensable nutrient and constitutes 60-70% of body weight for several reasons. It plays a crucial role in various physiological processes such as maintaining body temperature, transporting nutrients, and facilitating digestion and absorption. Since the human body cannot store water effectively, it must be replenished regularly to avoid dehydration, which can impair normal function and lead to serious health issues.

Additionally, water acts as a solvent for many biochemical reactions and helps in the elimination of waste products. Its unique properties, such as high heat capacity and solvent abilities, make it vital for maintaining homeostasis in the body. While carbohydrates, proteins, and fats are essential nutrients, they do not make up this significant proportion of body weight, nor are they as critical to immediate survival as water is. Understanding the pivotal role that water plays in the body highlights its status as an indispensable nutrient.