I haven't seen it on any other PC or MAC website before. It falls into the testingcheatsenabled true category.
Once you have typed in that cheat, you can ctrl click a moodlet, be it negative, positive, or neutral!
Let's say your Sim has a gnawing hunger moodlet.... ctrl click that moodlet (once you have done the testingcheatsenabled true cheat) and the hunger will disappear!
Same with a positive moodlet (though why you would want to get rid of that, I have no idea), and a neutral moodlet. This ALSO means you can ctrl click the fatigue moodlet, so that you can work out again, and again, and again!