Pet owners: How would you go about doing this (see details)?

I just got back from the vet and he told me I need to decrease the amount of food my kitties are eating. He said they should be eating ¼ cup of dry food per day, per cat.

I have two cats – Frasier is almost 20lbs and his sister, Sasha is about 8lbs. I am currently feeding them about 1 cup/day (total). Sasha tends to eat less than Frasier, and Frasier is always the one crying for food.

What I’ve been doing is feeding them in very small amounts throughout the day (when I’m home; when I work, I give them a little during the day and then spread the rest out at night).

The vet suggested cutting down the food gradually, which I will do over the next week. I am going to be out of town for 12 days and leaving friends to take care of the kitties. It will be easier for them to eat less when no one is here, mostly because they won’t have anyone here to harass But I am worried that Frasier is going to eat all of the food… leaving Sash hungry. It is not practical for me to separate them to feed them (I live in a teeny tiny studio) and certainly not reasonable to ask my friends to do that.

I’m stuck. Frasier really needs to drop some weight but he’s such a pain – always begging for food. How can I do this so that Frasier doesn’t drive me crazy and so that Sasha doesn’t lose weight?

Sorry for making this so long!!