"Fish was the staple diet of Londoners in the Middle Ages. It was cheap and plentiful, and, even more importantly, meat eating was forbidden on religious grounds on as many as 150 days of each year." Yet, according to 1Timothy 4:1-5 [1] Now the Spirit speaketh expressly, that in the latter times some shall depart from the faith, giving heed to seducing spirits, and doctrines of devils; [2] Speaking lies in hypocrisy; having their conscience seared with a hot iron; [3] Forbidding to marry, and commanding to abstain from meats, which God hath created to be received with thanksgiving of them which believe and know the truth. [4] For every creature of God is good, and nothing to be refused, if it be received with thanksgiving: [5] For it is sanctified by the word of God and prayer.
See All..., one of the "doctrines of devils" was "commanding to abstain from meats, which God hath created to be received with thanksgiving of them which believe and know the truth. For every creature of God is good, and nothing to be refused, if it be received with thanksgiving."