An additional comment can be made regarding the food Daniel and his friends rejected as recorded in Daniel 1. This article mentions the strict dietary laws of the Pentateuch and "clean" and "unclean" foods and the dedication of foods to the Babylonian gods. This is a possible significance of this passage, but not the only one. The best evidence for this view is the term "defile" in Daniel 1:8 and the general prevalence "clean" foods have in Leviticus and the possibility that one of Daniel's themes is fidelty to distinctive O.T., Jewish, practices.
There are stronger reasons to hold to another view and an interpretation that fits better with the general thrust of the book of Daniel. In Daniel 1 there are no references to "clean" or "unclean" and there are no direct indications that Daniel was concerned with Levitical dietary restrictions or with Babylonian worship (although false worship is a theme of Daniel 3). Daniel could have asked for foods that met the diet restrictions of the O.T., but instead he demanded "vegetables" and "water." This is not a commandment in the O.T. and is surprising if his concern was "ham and pork". Why not ask for unleavened bread and lamb chops? Why was he concerned about wine? There are no clear restrictions against wine in the Pentateuch for Hebrews other than Nazarites and Priests, so why would Daniel be concerned with the impurity of it? Also, Babylonians even commonly offered vegetables in worship to the gods, so it is not clear that Daniel could have been assured of ritual purity by partaking of those. He also could have asked for food not offered to gods. The emphasis does not seem to be on ritual impurity or purity.
The Hebrew term pathbag indicates the exquisite, sumptuous food of the wealthy. The underlying assumption is that it would be food that would make one look and feel more healthy, and be very tasteful, where as the implication of vegatables and water is that they are more impoverished foods that may lead one to look scrawny and malnourished but also have much less addictive power. This emphasis on "rich foods" is combined with Babylonian leaders' concern over the looks and health of all the young men. These point in the direction of the richness of the King's diet versus the (at least perceived) poverty of the food rather than ritual purity.
Proverbs 23 may be a parallel text to the concern that Daniel and his friends may have had. Proverbs 23:1 When you sit down to dine with a ruler, Consider carefully what is before you; 2 And put a knife to your throat, If you are a man of great appetite. 3 Do not desire his delicacies, For it is deceptive food. 4 Do not weary yourself to gain wealth, Cease from your consideration of it.
The text's implications seem to point in the direction of the king trying to bribe the Hebrews to love all that he could give them, and cause them to forget their status as captives far from their promised land, and so be able to control them. This is similar to the centuries later government of the Roman Empire seeking to control the masses with "bread" and "circuses." "Its not wise to bite the hand that feeds you." This fits well with the general theme of Nebuchadezzar's wealth and the oppulence in the book, as well as the emphasis of the book of Daneil that the King believes he is meeting all of the world's needs and only a fool would resist his "goodness" and delacacies. Daniel is no fool however. His God is the one who provides wisdom and nourishment, even when unexpected by others. If this is the true intepretation it would have the added benefit of being more immediately relevant to our own time when worldliness has considerable power over Bible believers just by spoiling their sensibilities with its seductive powers of over-stimulation.