Did you just feed your toddler rice and porridge?
Try to be creative in the choices of food.
I have been giving her macaroni, baked pasta with cheese, noodles (my girl particularly like udon and 'lao shu fen').
My girl loves soup, especially those herbal type. So usually with a bowl of rice, i will give her chicken herbal soup or ABC soup and she is happy to eat on her own. Sometimes she eats little but I am fine as she will still take her milk and she sleeps well (average 10-12 hours of sleep, including daytime naps).
I like exploring with my girl as I am trying to avoid having a picky eater.
Happy exploring and let your boy try on different texture of food. At 17 months old, he definitely has a lot more teeth than before.