Hi Emma,
Kate is almost 1 too, and for the last two weeks or so we have been having similar problems. I have used Annabel's recipies, and Kate wolfed down the lot - she used to make us laugh as we couldn't feed her fast enough. Then she started gagging on the food, and was even sick a couple of times. Looking through the board there seems to be several possible reasons, you'll have to see what suits your situation most.
It could be a 'strike' which usually means that your lo is getting more independent and wants to feed themselves. They reject the spoon. Is your ds ok with finger foods? If so then it might be it's time to let him get involved in feeding himself more - messy times ahead. Also this should pass over time.
Is he teething? if so eating might be a discomfort and so he doesn't want to. Experiment with softer foods as these take less 'chewing' and might be easier on the gums.
Does he have a temp? refusing food might be a sign of a bug or virus. If you think he might have a temp check with the gp asap.
Does lo have reflux? although it is usually better with solids, he might be suffering a little, check out the reflux advice if you think this is the case.
HTH
Tina