Beat It came out first and not Eat It. Michael Jackson's song came out in 1983, whereas Weird Al's son came out in 1984.

The new movie, Weird: The Al Yankovic Story, which is a biographical parody film, mentions the two songs, Eat It and Beat It. The movie revolves around Alfred Matthew's "Weird Al" Yankovic's life. However, some plots have been exaggerated. 

And one of the plots is that Weird Al, a rising singer, writes a song, Eat It, and it becomes a major hit. However, before a big show, Al discovers that Michel Jackson had taken Eat It and parodied it as Beat It. 

This specific scene in the movie has made many netizens wonder if that is the truth behind these songs. Both of these songs exist in reality, and the composer and singers behind the songs are Michael Jackson and Al. 

But, since it is an exaggerated story of Al's life, this scene has been reverted to what happened in reality. The song Beat It was released in 1983, and Al was the one who parodied it to Eat It in 1984. 

Beat It is the song from Jackson's sixth studio album, Thriller (1982). It reached number one on the Billboard Hot 100 and remained there for three weeks. It also reached the top spot on Billboard, placing the song at No. 5 in 1983.

Eat It came out in 1984 as a parody version of Jackson's Beat It. And the lyrics were rewritten to be about an irritated parent striving to convince their picky child to eat anything, much less to eat correctly, as per Wikipedia. 

The song went a massive hit and even became number one in Australia. In contrast, Beat It had only reached number three in Australia when it was released. 

Yankovic even won a Grammy for Best Comedy Recording category for the song. In addition, it reached number twelve in the United States, becoming his first top 40 success.