Read this tip to make your life smarter, better, faster and wiser. LifeTips is the place to go when you need to know about Monitors (Varanids) and other Reptile topics.
They'll eat you out of house and home if you let them, and some of them will eat anything at all including things that aren't good for them.
Don't feed your monitor lizard human table scraps, or muscle meat alone. They need whole carcasses (generally mice or rats) to stay healthy.
Make sure the mice you are feeding are "lean mice", not carrying too much fat due to a fatty diet. You can also balance out the fat in your monitor's diet by offering some crickets and earthworms. You can also supplement with a little canned dog food, but use one for elderly dogs that is low in fat. And be sure your monitor gets enough exercise.
Once they reach adult size (3'), two or three food items sized a little smaller than the animal's head, offered twice per week, is plenty. Although if offered the opportunity they will eat much, much more. As hatchlings (up to 1'), they will want three or four food items every two to three days.