Zoe Saldana put herself on a ''strict'' diet when she was younger.

The 39-year-old actress has revealed she used to restrict her diet when she was first starting out her acting career, as she believed having a fit body would lead to greater accomplishments in other areas of her life.

She said: ''When I was younger, I was more strict. I felt I needed to control that part of my life in order to feel I was going to be successful at something - because we often equate success with our physical beauty. It's so f***ed up!''

But now, Zoe is more forgiving with her diets and says she finds ''strength'' in being a mother of three to her sons, three-year-old twins Cy and Bowie, and 16-month-old Zen.

The 'Guardians of the Galaxy' star - who has her sons with her husband Marco Perego - said: ''My boys are a constant source of strength for me. They keep me on my toes, reminding me how much I still have to learn and grow as a person.''

When she gets the time in between her hectic life as a movie star and mother, Zoe uses her experience from her time as a ballet dancer to keep her body in shape, and takes a moment to stretch with yoga exercises.

Speaking to Women's Health magazine, she said: ''I love having that kind of intimacy with my body and getting my body to do things I never thought I could do.

''I often take for granted how helpful stretching and breathing exercises are. Yoga reminds me to breathe and slow down.''

Zoe's health comments come after she revealed in an interview last year that she doesn't have time to hit the gym much these days, and so focuses on healthy eating instead.

She said: ''I can't work out regularly, so I compensate by eating a lot healthier than I might otherwise. Once you have relatively healthy eating habits, your workout can become playing with your kids, strolling around the neighbourhood, playing airplane or just changing diapers.''