Comedian Guy Branum Claims Man Hit Him on Flight for Being Too Fat

3:30 AM PT -- Delta Airlines has issued a response in regard to comedian Guy Branum claiming another passenger elbowed him for being overweight on a flight from New York to Los Angeles over the weekend.

The airline tells TMZ ... "Delta sincerely appreciates the actions of our crew and customers for deescalating this situation. We apologize to our customers for the delay and thank them for their understanding. Delta’s Customer Care team is reaching out to speak directly with our customer as we look into his claims."

Comedian Guy Branum is sharing an air travel nightmare ... he says the guy sitting next to him on a Delta flight gave him an elbow to the ribs because he felt Guy was too fat for the middle seat.

Guy tells TMZ ... he was on a Delta flight Sunday from New York to Los Angeles when a fellow passenger hit him before takeoff. He says he reported the alleged incident to a stewardess and the flight was delayed while Delta investigated.

The comedian, who appeared often on "Chelsea Lately" and the "Juicy Scoop with Heather McDonald" podcast, posted video from the interaction and he's in the middle seat, arguing with a man seated in the aisle. The man mentions being a member of Weight Watchers and they bicker about the armrest and personal space.

Guy says the flight crew was "amazing" and "supportive," but the Delta Red Coat who came over to investigate "treated me like an object."

Ultimately, Guy says his flying foe switched seats with another woman across the aisle.