My full grown BCI boy only eats once every 3 weeks, and every now and then he'll get a small meal in between. But at 7 ft a Large rat is more than enough to sustain him at proper weight and activity. Occassionaly he will get a Jumbo (for a month period) or a medium (for every couple of weeks) to change things up. Using this since he was 3 years old, he hasn't missed a meal in the last 7 years I've had him.