Here is a study that was an interesting read for me because I keep Texas collared lizards in my terraria.
Stomach contents were examined from 48 collared lizards. On average, 3 prey items were found in each lizard, consisting of 2 different kinds of prey. Grasshoppers formed the bulk of the prey eaten by far, which was surprising because other potential food items were plentiful in the area and collared lizards are thought to be opportunistic eaters.
General comparisons are made with populations from other states. It seems different populations have different dietary favorites.
That number of about 3 is fairly consistent with numbers taken when I am hand-feeding my terrarium lizards– usually 2 or 3.
Here’s the link: