At what point should I start to worry?

[Hope54321]

My 10 months old baby eats 1 proper meal (usually breakfast), he only nibbles at lunch and dinner. I’ve also noticed he doesn’t breastfeed for as long as he used to. He has 4 good feeds a day and all the other times he just latches on for a few minutes.

At what point should I worry about his food intake?

As long as he isn't losing weight or showing signs of being dehydrated I wouldn't worry about it too much. My DD (now 2.5) went through many phases at different ages where her appetite seemed to drop but it always picked back up again. She definitely didn't eat 3 proper meals before she was 1, it was more just little tastes of things at our mealtimes although like your LO she always liked her breakfast!

Could he be teething? My DD was always more fussy with food when she had a tooth coming through.