I had a simple auger-fed model for our cat. I realized very quickly she could reach up there and get food meant for the next cycle... and eventually realized I didn't care. If she takes the food intended for the next cycle, less comes out next, and if she goes into the next meals portion again, she's getting the same amount of food, and some stimulation for free trying to get it out.
I thought this too! Except our cat never lost any weight, and seemed to be getting fatter, until we put the feeder in a laundry basket, and now they can't get access anymore and have slowly been losing weight.
The laundry basket is the tall type, with a hole cut in the bottom and a funnel installed, plus a chute screwed on for good measure. It's mounted on the wall, raised about 1ft, so they can't get their grubby little paws in there.
