When DD was 8 months old, I packed 24 hours worth of powdered formula & baby food in glass jars plus a few small bottles of juice. At the time, there were many incidents of planes being held on the tarmac & for up to and over 9 hours and I know it's possible for planes to be redirected and end up in a city other than your destination city so to me, what I packed was a reasonable amount. There was no way I was going to be stuck with my baby for that long on a plane or in an unfamiliar city without everything I needed. No one batted an eye at all of our stuff. We even had liquid medicine that had to be in a soft-sided cooler with an ice pack. We just declared all of the liquids when we approached TSA and they nicely waved us on through.