I recall AllEars December newsletter had a section on Dining changes in 2012 that said something about this. I went back to find it. Here it is...
"Meal and snack entitlements are linked to each person on the Key to the World (KTTW) card. Present your KTTW card at the time a meal or snack is purchased and specify the number of meals or snacks being redeemed for guests ages 10+ and for guests ages 3-9".
I always thought that this was kept track of depending on what you ordered. I mean the computer either recorded a kid's meal or an adult meal. No??