uninterested in food

My 13 month old is going through a no eating phase right now. There comes a point in his meals that we just can't feed him anymore, he spits it out. We thought maybe he was teething and therefor uninterested in food but it's been going on for about 2 weeks. He wakes up hungry later so I know it's not cause he's full..... Anyone else going through this? How long did it last?