The First Ever Clinical Trial of Diet and Nutrition?

From Daniel 1: 1-16

In the third year of the reign of Jehoiakim King of Judah came Nebuchadnezzar King of Babylon and he set Jerusalem under siege.

The King asked Ashpenaz the master of his eunuchs, to bring him some of the Israelites, in particular the children of nobles and royals. These children had to be able, wise and beautiful, well tutored, understanding the arts and sciences. He wanted to teach them the learning and language of the Chaldeans.

The King said that they should be well fed with his own foods and wine, and after 3 years he would see them.

Now among these Israelites were Daniel, Hananiah, Mishael, and Azariah. Daniel did not want to eat the kings food. He said it would defile him and he spoke to the Prince of the Eunuchs who listened sympathetically to him.

The Prince of the Eunuchs said to Daniel, if you don’t eat the King’s food and you look ill and pale compared to our own boys, the King will surely cut off my head for failing to look after you.

Daniel said to the Eunuch, I will make a bet with you. Take a few boys for just 10 days and give them only vegetables and pulses to eat and water instead of wine, then compare them with the other boys who are eating the King’s rich food and drinking his wine.

At the end of ten days their faces appeared fairer, and they were more beautiful than all the youths who ate of the King's dainties.
So the steward took away their dainties, and the wine that they should drink, and gave them veggies and pulses. And Daniel proved himself to have knowledge and skill in all things as well as in visions and dreams. And thereafter in all matters of wisdom and understanding, the King found him 10 times better than all the magicians and enchanters (and gurus) who were in the Kingdom.