Kate Middleton’s Diet Trick Revealed — Plus 9 Stars Share Their Weight Loss Secrets!

Ever wonder how Kate Middleton manages to maintain such a trim figure after giving birth to two children? Now we know what her diet secret is: green juice!

"Pippa [Middleton] arranged to have fresh juices delivered to Kate every three days," a family source revealed to Us Weekly. "It was a surprise treat. Kate used to blend her own juices and this is much easier.

"She just enjoys green juice in the morning. It's Kate's go-to for an extra boost. Pippa was the one who got [the royal family] into juicing. They all love it!" the insider added of Kate, 33.

Click through the gallery below to see additional weight loss secrets from your favorite stars including Jada Pinkett Smith, Brooke Burke-Charvet and more!