Eating/Drinking..how long does it take you?

I also posted this on the RNY board, but I was just wanting some additional input. How long should it take me to be eating a meal (1/2 cup)? Half hour? What about drinking? I know I need to sip, sip, sip. But I don't know how long it should actually be taking me to drink say a 16.9 oz bottle?

My doctor says to eat mindfully for 20 minutes. Although the majority of the time, I am full by around 15. I use my toddler's forks and spoons, so it also helps with the time. I never calculated how long it would take to drink a bottle of water though. I just kinda have one with me whereever I go. I also put rubber bands around them, so I know how much I have had in a day. I try to get in about 4 or 5 of the 16.9 oz bottles.

I was told that is should take about 25 to 35 minutes to eat about 1/2 cup to 1 cup. My doc also said not to take longer than 35 minutes to eat a meal because then it starts to turn into grazing which is a big no-no! I usually take about 25 mins. to finish a meal. Cheers!