It was the normal, biblical and cultural thing in early Christianity for new gentiles converts to keep the holy days of the Lord Jesus Christ. There were no other alternatives and if anyone had been advocating something different it would have been a huge area of contention and would have generated more controversy in scripture than did the circumcision issue...and the circumcision issue generated a large amount of discussion within the pages of scripture. So the answer is yes, both the the Lord's holy days and his food laws...with the difference being that Christians followed the teaching of Jesus on separating out what was scriptural from what was based on the tradition of men.