Daniel 1:11-15

But Daniel said to the overseer whom the commander of the officials had appointed over Daniel, Hananiah, Mishael, and Azariah,

“Please put your servants to the test for ten days, and let us be given some vegetables to eat and water to drink.

Then let our appearance be examined in your presence and the appearance of the youths who are eating the king’s choice food; and deal with your servants according to what you see.”

So he listened to them in this matter, and put them to the test for ten days.

And at the end of ten days their appearance seemed better, and they were fatter than all the youths who had been eating the king’s choice food.