We had the same problems with DD1 awhile ago. The advice I was given by a paed dietician was 'persistance and no giving in is the key'. Just keep offering the good stuff, remove all temptation of the naughty stuff from the house (or hide it if you have a weakness yourself) and eventually they will return to good eating. Alot of parents fall into the trap of giving in and letting them eat unhealthy food just to get them to eat a 'decent' amount, thinking that they will starve themselves. Children do not have this adult ideal of being able to starve themselves for whatever reasons. If they are hungry they will eat what their brain tells their bodies they require. Its usually a phase most children go through, different developmental milestones can change eating patterns, like walking, talking, teething, independence growth etc but given time and of course making sure the healthy food is continuosly offered and they should return. DD1 is slowly returning, she has almost finished cutting her 2yr old molers as this seemed to coincide with her lack of interest in anything but weetbix and nutrigrain. Remember they only require a serving the size of their clenched fist 3 times a day, with maybe 2 small snacks in between, its amazing how little the require when its put like that. Dont stress if they wont sit down and eat a proper meal, their only little and its fine for them to graze, they are easily distracted and find playing and learning more interesting, I found letting her come back to the table and eating on and off during our meal times that she ate more. And being a little sneaky and hiding foods made me feel a little better to.