Meghan Trainor: I used to really worry about how I looked
31 March 2015 Last updated at 07:52 BST
Meghan Trainor is a successful pop star who performs all around the world.
But she wasn't always so confident. Growing up, she felt insecure about how she looked and often missed out on things because she was worried.
She's spoken to Newsround about how she overcame her worries and tells children in similar circumstances, her advice.