I was listening to a personal training podcast where some personal trainer to the stars said that before he even takes on a client, he tells them to halve the amount they eat, and double the amount of water they drink, and to do that for a month before he takes them on as a client, so thought if it's good enough for Hollywood, it's good enough for me. So basically I help myself to my normal portion at a meal, divide it in 2, eat half, and put the rest in the fridge for tomorrow. It seems to be working.