DS2 is 14mo. Unlike DS1, who was feeding himself well with a spoon by 9mo, DS2 did more of a BLW style thing and is still relatively incompetent with cutlery but good at eating with his fingers.
Which would be fine if he was eating anything at all. Since he had his MMR a month ago, he was gone off solids totally and only wants to breastfeed. This is particularly when we are not home, whether we are out locally, at friends' or on holiday.
I normally work full time and he has to eat a little at nursery but he has been consuming little even there. At home, he will eat a little too but very much less than a month ago.
I'm still breastfeeding so he isn't about to get dehydrated but today (we are on holiday) he ate:
One spoonful of yoghurt
One tiny bite of banana
One blueberry
Water
He was offered as well:
Bowl of porridge
Bowl of Cheerios
Yoghurt
Toast
Raisins
Sandwich
Apple
Banana
Pineapple
Biscuit
Homemade spaghetti and tomato/veg sauce
Toast
Strawberries
Everything was refused. He has several (million) large breastfeeds so he isn't in danger of not having enough calories, just avoiding food. He doesn't seem to have lost weight really so I'm not worried about that - just his lack of nutrition and my breasts falling off from overuse! 
I'm at a loss. We never make it an issue. DS1 can be a fussy three year old about food sometimes but DS2 is just completely uninterested.
Could it be that he's been feeling crap since the MMR? He doesn't seem ill in himself so struggling to find a reason for this.