I think it also has a lot to do with what type of treats you feed! I feed a premium bird seed (16% protien),dried meal worms, fresh greens and veggies that are in season (tomatoes,squash, pumpkin, etc). In the winter they get a 5gal bucket of fresh greens every day stuffed into their large suet cages, a can full of bird seed to scratch for.. And they get a handful of dried meal worms every day --placed under a basket of dried leaves.. I try to feed treats that they would find if they were free ranging all day..seeds, bugs, sprouts,greens etc. I like to make them 'work' for it a little. Like hanging the greens (cage) a little higher, putting the worms and birdseed under grass/leaves or mixed in their shavings. I am cutting holes in their pumpkins and let them work to get the seeds and goodies...
Most of my table leftovers go to our large dogs..
There is a great list of good treats on here somewhere.. Do a search and see if you can find it..