My son has started having purée food now and has done for nearly 2 weeks.. morning & late afternoon,…

My son has started having purée food now and has done for nearly 2 weeks.. morning & late afternoon, he has 5 bottles a day 7oz in the morning & night then 6oz during the day but I've noticed now he isn't drinking as much anymore it's like 5-6oz at every bottle expect the night one which is still 7oz, is this normal to be drinking less this quickly now he has started food?