Every time Christina Aguilera makes an appearance somewhere we see less and less of her. When she took the stage at the Billboard Awards earlier this month, jaws dropped. Now, Christina's fessing up about what motivated her to shed 20 pounds and how she did it! Turns out the singer's skin is rather thin. A pal tells US Weekly that Christina was going through a bad time because of all the criticism about her weight gain. Try saying anything bad about her now though! She also enlisted help from a food delivery program and stepped up her exercise routine. Keep up the great work!