11 months no longer into his food

My baby is 11 months this week and just isn’t eating like he used to! He used to love eating- would eat so much and would eat everything! Now he just throws things around, bangs on the table, makes a mess, but barely eats a few bites! Even his poops have started to look more like breast milk than anything else. He isn’t sick, he’s running around, playing, full of energy, but he’s glued to my hip, won’t let dad do anything anymore. I started work about a month ago so I know there’s some separation anxiety there but why won’t he eat??