Well, this divine decree isn’t talking about food. It’s actually a metaphor for Christianity opening its doors to Gentile converts instead of just Jews. This is how Peter himself interpreted it:
27 As Peter talked with him, he went inside and found many people gathered together.
28 He said to them, “You know how unlawful it is for a Jew to associate with a foreigner or visit him. But God has shown me that I should not call any man impure or unclean.
29 So when I was invited, I came without objection. I ask, then, why have you sent for me?”
…
34 Then Peter began to speak: “I now truly understand that God does not show favoritism,
35 but welcomes those from every nation who fear Him and do what is right.
36 He has sent this message to the people of Israel, proclaiming the gospel of peace through Jesus Christ, who is Lord of all.”
A better passage would be Mark 9:17, which explicitly talks about food:
14 Again Jesus called the crowd to him and said, “Listen to me, everyone, and understand this.
15 Nothing outside a person can defile them by going into them. Rather, it is what comes out of a person that defiles them.”
17 After he had left the crowd and entered the house, his disciples asked him about this parable.
18 “Are you so dull?” he asked. “Don’t you see that nothing that enters a person from the outside can defile them?
19 For it doesn’t go into their heart but into their stomach, and then out of the body.” (In saying this, Jesus declared all foods clean.)
20 He went on: “What comes out of a person is what defiles them.
21 For it is from within, out of a person’s heart, that evil thoughts come—sexual immorality, theft, murder,
27 As Peter talked with him, he went inside and found many people gathered together.
28 He said to them, “You know how unlawful it is for a Jew to associate with a foreigner or visit him. But God has shown me that I should not call any man impure or unclean.
29 So when I was invited, I came without objection. I ask, then, why have you sent for me?”
…
34 Then Peter began to speak: “I now truly understand that God does not show favoritism,
35 but welcomes those from every nation who fear Him and do what is right.
36 He has sent this message to the people of Israel, proclaiming the gospel of peace through Jesus Christ, who is Lord of all.”
A better passage would be Mark 9:17, which explicitly talks about food:
14 Again Jesus called the crowd to him and said, “Listen to me, everyone, and understand this.
15 Nothing outside a person can defile them by going into them. Rather, it is what comes out of a person that defiles them.”
17 After he had left the crowd and entered the house, his disciples asked him about this parable.
18 “Are you so dull?” he asked. “Don’t you see that nothing that enters a person from the outside can defile them?
19 For it doesn’t go into their heart but into their stomach, and then out of the body.” (In saying this, Jesus declared all foods clean.)
20 He went on: “What comes out of a person is what defiles them.
21 For it is from within, out of a person’s heart, that evil thoughts come—sexual immorality, theft, murder,
22 adultery, greed, malice, deceit, lewdness, envy, slander, arrogance and folly.
23 All these evils come from inside and defile a person.”