My two love green beans, it is the only thing they get as a treat and I also add them to their kibble. As long as they agree with your little one, it doesn't hurt and it also does not add very many calories.
Jada tends to put on weight so easily and the green beans are all I have found I can treat her with and not pack extra unneeded weight.
BTW my pigs eat about a 1lb bag a week