If your Sim is very depressed or has a low attribute, enable the move_objects_on code and pause game play. Click on the Sim in buy/sell mode and click the bottom of the screen to delete him/her. Once deleted, go to the live mode and double clock the person's head icon to go to where that Sim is located. Everything should be close to full. Note: Wave the game immediately before performing this cheat, or you will lose any career changes or points you have earned.
-Put in a hot tub room containing a chair, big bath tub, and lots of paintings. This will definitely get their energy back up.