She says she owes it all to her London-based fitness guru and friend Dalton Wong (below), who first transformed her body for X Men: First Class in 2010.
In the forward for his new book, The Feelgood Plan (out on March 8), Jennifer, 25, says she still swears by Dalton’s tips and tricks today.
“We spent 10-12 hours a day together for three months working out between filming on [the X-Men] set,” writes Jennifer who rocked the red carpet again at the recent Oscars and Vanity Fair after-party.
“He changed my body for that movie and gave me the skills to change my life.”
Jennifer says the secret was a health and fitness plan that never deprives her of indulging in her favourite vices from time-to-time.
“I could never live on a ‘diet’,” she adds. “Dalton taught me how to eat, move and live a delicious but healthy life.
“We remain good friends; when I’m in London I love to train in his gym, then afterwards we go out for burgers and fries with his family. It’s all about balance.”
Dalton says that when he first met the Joy star she’d never trained her thought about what she put in her body.
“I feel I am the trainer that started her education in nutrition, and taught her what foods would make her feel good,” he says.
“What I taught her five years ago she still uses today.”
The trainer says he told Lawrence “it’s not about starvation diets” and educated her on the importance of consuming a big breakfast and lunch.
“It’s about eating protein, a lot of vegetables, colourful foods, and foods that are dense in nutrition, like greens,” he adds.
He also believes in a balanced approach to exercise and combines yoga, Pilates and meditation into Jennifer’s routine in order to not exhaust her.
“I couldn’t exhaust Jennifer so much that she felt so sore at work the next day, my job was to make her feel better, fitter, and stronger, so that she could work better,” he says.
“It’s okay to eat chocolate, it’s okay to eat ice-cream, as long as you’re nourishing your body as well, and not depriving it of what it needs.”