Christina Aguilera has adopted a healthy meal delivery plan to help her slim down. The Beautiful hitmaker showed off a trim new look earlier this month (May13) when she performed with Pitbull at the 2013 Billboard Music Awards in Las Vegas, and the weightloss is partly due to the Fresh Diet premium meal plan, which features meals amounting to a maximum of 1,600 calories a day, reports Us Weekly. A source tells the publication, "She did it all on her own. She goes online and picks out her food." Aguilera is also being whipped back into shape by fitness pro Tee Sorge, who worked with the star for her 2010 movie musical Burlesque. She is also passionate about yoga, and the lifestyle change has helped her drop an estimated 20 pounds (nine kilograms). And the singer is relishing picking out outfits for her new figure. Her stylist Simone Harouche says, "She's really into dresses that highlight her decolletage and her waist. She's showing off her amazing figure."