We get asked this question every day, so we thought we would write a quick explanation. The short answer is yes, however, beware that you do not abuse it.
Here is the longer explanation. When we eat food, we chew it, swallow it, and our stomach and digestive tract use acids and bacteria to break it down. All of this happens before we release it to be flushed into the septic tank. When you put food through the garbage disposal, you are bypassing the first digestive process, so the bacteria in the septic tank have a bigger job to do. (See our blog post on probiotics.)
You also have to remember that if you are on a septic system, your septic tank is capturing solids and debris and only allowing water to leave. It will only hold so much solid material before the debris overflows into your absorption area, clogging the soil and preventing the system from working. Overuse of the garbage disposal could fill your septic tank with solids, meaning it needs to be pumped out more often than usual to ensure proper care of the absorption area. (See our blog for more information on related topics.)
We have found the best practice is to scrape pots, pans, and plates off into the trash or compost bucket, then whatever is left is fine to run through the garbage disposal.