Maybe you could put down 1/2 in the morning (or whenver is convenient for you in the day) and leave 1/2 at night, so they don't wake you up, begging for more?
My old cat (she passed away last year at 17) would sit next to your head at wee hours of the morning so when you woke up, her face was right there. My mom's cat (who has some weight issues too, although she weighs 15 lbs despite attempts to reduce her weight) will walk over her in the morning to get fed- and believe me, you feel it!