By no means is it necessary to feed your Savannah Monitor live animals and prey, so there are other options. Monitors eat insects, crustaceans, eggs, birds, small mammals, and market foods such as deli meats. More specifically they eat baby mice ("pinkies, fuzzies, hoppers"), crickets, grasshoppers, beetles, earthworms, rodents, and canned cat or dog food. Be careful with canned cat or dog food since it can give a lizard diarrhea. Snails and slugs are also great food. A Savannah Monitor will probably rip off the snail's shell itself. In general, Savannah Monitors will probably eat any prey that they can overpower.
Things to Consider
The wild is a possible source of food for your monitor, but please be warned that food collected in the wild may contain pesticides or disease.
Proper temperature is just as important for digestion and metabolism as diet and ultraviolet radiation.
Be careful when feeding your Savannah Monitor because if it is hungry enough it will nip at anything that moves.
It is best to keep diet variable and to sprinkle vitamin supplement powders on food to ensure good nutrition.
Make sure your lizard gets enough exercise to keep from becoming obese, which may shorten its life-span.