The answer is: 10

Dan 1:13-14

Daniel and his friends found themselves in quite the culinary challenge while they were hostages in Babylon! To prove their commitment to their faith and ensure they stayed healthy, they chose to eat a simple diet of vegetables and drink only water. This was no insignificant leap of willpower, especially in a culture lavishly filled with rich meats and wines.

By meticulously observed over ten days (as per Daniel 1:13-14), these four young men showcased an impressive endurance that captured everyone's attention. Interestingly, at the end of this period, they were found to be healthier and more robust than their fellow young men who indulged in the king's food. This story isn’t just about food; it resonates with the importance of maintaining personal principles even in the face of great pressure, and of finding strength in simplicity.

On a fun side note, Daniel isn't just the character from this book–but he also echoes the trials faced by the three Hebrew boys: Shadrach, Meshach, and Abednego, who later stand resolute against idol worship. Their resolve underscores a recurring theme in biblical narratives, where commitment and integrity often lead to unforeseen blessings.

This particular account has led to various modern vegetarian movements and discussions on dietary choices, inspiring many to transform their eating habits in pursuit of healthier lifestyles often rooted in spiritual conviction. So the story of Daniel isn’t just ancient; it’s ever so relevant, inspiring many today to ponder the power of simplicity and commitment!