In the Bible, it is said to never add or take away from the words of the prophecy in the book(Rev 22:18-19).
Therefore, those, who follow exactly as the words of God in the Bible, can be called righteous and worthy to receive salvation.

When following the instructions of God regarding food, this kind of absolute faith is also required.
When we read the Bible, God gives different instructions in each age about the same food. Once He says to eat it, while in other times He banns us from eating it.
For example, in the age of Adam and Eve, God only allowed them to eat vegetables and fruits.
However, after a thousand years, in the age of Noah, God suddenly orders to eat not only vegetables and fruits, but also all kinds of meat. Here, the right faith of Noah would be eating all kinds of meat, as God has commanded him, even if he has never eaten animals until now.
So from the times of Noah, God's people ate all kinds of animals on land. However, in the age of Moses, God all of a sudden divides animals into two groups- clean and unclean.
If the animal was declared unclean by God, Moses were not to eat that animal, even if he has always eaten it until now.
In this way, one same animal was allowed to be eaten for Noah, but not for Moses. However, our forefathers of faith has shown us good examples of obeying to the words of God about food with absolute faith.

Then what kind of regulation about food was given to us living in the New Testament times?

Acts 15:28-29 It seemed good to the Holy Spirit and to us not to burden you with anything beyond the following requirements: You are to abstain form food sacrificed to idols, from blood, from the meat of strangled animals...

In this age, God told to abstain only from sacrifices made to idols, blood and meat of strangled animals.
Then what kind of faith can be said as righteous and worthy to receive salvation in this age? Faith that eats everything, except for the above mentioned food.

However, there are certain religious groups that do not follow this regulation about food, with the intention to worship God "better". How does God see their action?

1 Timothy 4:1-3 The Spirit clearly says that in later times some will abandon the faith and follow deceiving spirits and things taught by demons. Such teachings come through hypocritical liars, whose consciences have been seared as with a hot iron. They forbid people to marry and order them to abstain from certain foods...

According to this prophecy, the Catholics forbid priests and nuns to marry and the Seventh-Day Adventist Church abstains form eating meat, insisting on vegetarianism.
They may insist that it is to serve God more sincerely and better, but what did God say? God said their deeds are teachings of demons that came through hypocritical liars.

Therefore, let us not add our thoughts, even if it is with good intention, but just follow the teachings of God as said in the Bible.