Fat Adaptation

I’ve been doing intermittent fasting for over three weeks now. I eat lunch at 12 and dinner at 6, no snacks. I understand that hunger comes in waves, so I’m not scared of it when it comes. I am not driven to eat outside of meal times, but there are times when I am truly hungry. How long does it usually take to not feel hungry with IF? Am I prolonging reaching fat adaptation by eating sugar/flour as my joy eat? (I have planned a treat just once per week.) Thank you!