Short answer - 1200 grams and up, unless they are breeding females gaining weight for breeding or recovering after laying eggs.
Long answer - Feed youngsters 1000 grams and less every week. They are growing a lot and use every bit of food they can get. Adults are a different story. I started feeding my adult collection every other week, and the only thing that is different is the amount of dookie I have to clean up. Growth rates, appetites, etc, has remain the same. They don't need nearly as much food as we think to thrive. There's even arguments out there that calorie restriction in ball pythons and other boids is important to their longevity due to the amount of energy their system needs to constantly be digesting food - they've evolved to fast at times over the centuries - therefore they should eat less in captivity as well, especially considering the sedentary lifestyle that captive snakes live.