the third day in kindergarten

It is the third day for my son has new life in kindergarten. He seems adapt his kindergarten life gradually. He got up in the morning without delay when we woke him up. He just cried for a while when my mother send him to kindergarten and left. He still ate a little at noon, he is very fussy about food, He doesn't eat if the meal is not tasted whatever how hungry he is! He is very thin already. I am afraid it will lead to Malnutrition . Parents are always worrying about their kids. It will not be end even when they are grow up to be adult.