“Yesterday my son (22) and husband (50) got into a huge argument over something as ridiculous as who can eat the most. It all starts the same way – as a joke, and gets really heated. I have to leave the room or even leave the house. What can I do?”

Take up your life
If your husband or your son (neither of whom is asking the question) wants to solve the problem then the one wishing to do so must similarly decide to exit the room or the house when the other initiates such an argument. This issue takes one, not both, to solve.
If I wanted to “go deep” I might suggest your husband is NOT at peace with his family of origin (his parents and siblings) or that your son desires acceptance from his father and therefore provokes any attention he can get – but neither adult man is seeking my guidance.