The basic idea is that you can buy cheaper, more fatty, ground beef and by draining the fat. It’s a great idea and I’ve been doing it for some time. Instead of simply draining the beef though, I put in a little water and boil it at the end for just a couple of minutes. Draining that water out seems to get all the last fat out.
I still buy the leanest beef to start with just to ensure that I’m getting the lowest fat I can. Often times, I’ll get ground turkey instead, as it’s a very lean and cheap alternative. Both work well together in many economical meals.