Kaycee Stroh received hate mail from Disney Channel viewers.

The 40-year-old actress found fame when she took on the role of Martha Cox in the 2006 runaway hit 'High School Musical' for the television network and starred opposite Zac Efron and Vanessa Hudgens but was left "devastated" when fans of the movie criticised her appearance.

She told People: "My whole life I was a bigger, muscular, curvy girl. The one thing I thought would always hold me back was the very thing that made me who I am, and it made me stand out that day.

"It all made sense to me. It was like my whole life came into focus -- I was supposed to be this way, I was made this way for a reason, and I needed to change the world's perspective on this.

"[Someone wrote into Disney, criticising them for casting] someone as unhealthy as myself. If they only had taken the time to get to know me and realize that I grew up dancing five hours a day, and that wasn't at all the situation.

"It was so devastating to see how people just prejudge others based on something as shallow as their outer appearance while they're here on this earth."

But the star - who appeared in all three of the 'High School Musical' films and also had a small role on 'The Suite Life of Zack and Cody' around the same time - is glad she had that sort of experience when she did because it taught her to "build empathy" for other people.

She said: "I'm glad it happened when I was young and fresh in the industry because I really learned quickly to build empathy for others."

"Healed people don't hurt people, and I hope those people can someday find happiness and heal their inner trauma, or the generational body trauma that was passed on to them.

"I really just look at it like, 'I'm sorry for you.' I hope you find happiness and realize someday that there's so much more to life than that."