Whinging while eating

Hi,

Don't know if we're going through a phase but DS has started to make a real fuss when eating, mainly on his dinner.

He is a good eater and sits there with his mouth open, but at the mo, even though he has his mouth open he's really fussing and whining.

Leading me to think, is he not hungry, doesn't like it, or just being noisy, straight after he stops eating, he's all happy.

Breakfast and lunch are ok and if I feed him when out he doesn't make a peep, except yummy noises.

Does anyone else get this?