My 3 and a half month old that weighs 15 lbs has drank this while 2lb can of formula in 4 days. That's thickened with oatmeal cereal, and solids mixed in. I'm very concerned.. it seems like hes constantly hungry. And he's eating every hour and a half and he wakes up around 8am and is in bed by 9pm. I haven't brought it up to his doctor but I'm concerned. He's eating 49oz a day, but according to his weight he's supposed to eat 37oz a day. I'm feeding him solids separately to and he still eats about 2 hours after I feed him the solid. Has anyone went through this?