Manger told me I was getting fat... Advice please.

UPDATE: HE'S MANAGER/OWNER

Yesterday after I got off work, I grabbed a To-Go from my job but I ate in the lobby because I was really hungry. Anyways, my manager is a real jerk. Calling me fat isn't the only thing he said, he always has plenty of things to say but I was shocked by this one. So he saw me eating and was like "You're getting big on the sides, I see your fat" and it didn't really hurt my feelings that much because I know I've put on some weight lately. So I kinda ignored it and just laughed. But later on one of my co-workers wanted me to go with her to ask my manager a question, so I did. As soon as he saw me he was like "Done eating fatty?" And I was like "yeah" at this point I was embarrassed but it made me mad because then he insulted my mom by calling her big and saying just because she's big doesn't mean I have to be. He also told my co-worker this. So I was mad but disappointed in myself because I didn't even say anything... I was just too shocked and embarrassed. I'm about to go in at 4, and I'm wondering if he talks to me like this again should I just walk out and quit? I'm so tired of working there. I can't hold it in anymore.