Check out this answer from Consensus:

The claim that the human body is about 97% water is not supported by scientific evidence. The human body is composed of approximately 60-70% water, with variations depending on the specific tissues and organs. This percentage is crucial for maintaining various physiological functions and overall health.

The human body is composed of a significant amount of water, which is essential for various physiological functions. This analysis aims to determine whether the claim that the human body is about 97% water is accurate, based on insights from multiple research papers.

Key Insights

• General Water Content in the Human Body:

  • The average adult human body is composed of approximately 60-70% water, with variations depending on the specific tissues and organs1 2 4 6.

  • Specific organs and tissues have different water content: skin, muscles, brain, and other major organs average around 70%, while bones and teeth have significantly lower water content1.

• Variations in Water Content:

  • Water content varies across different tissues: blood contains about 90% water, while bones contain about 22%6.

  • Fat tissue has a lower water content, around 50%1.

• Misconceptions and Clarifications:

  • Some sources inaccurately claim that the human body is composed of 90% water, but this is not supported by the majority of scientific literature5.