As long as he's still on breast milk or formula (and he should be) he'll be fine nutritionally. My boys didn't start solid food until 6-7 months (maybe later for my youngest, he still only had 2 teeth on his 1st b-day) They also didn't really do the baby food thing. They usually just had modified versions of what we were eating.

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Once the game is over, the king and the pawn go back in the same box.