Jennifer Lawrence attributes her slim shape to her trainer and good friend, Dalton Wong.

According to the 25-year-old movie star, she doesn't go on diets. Instead, the London-based fitness guru taught her "how to eat, move and live a delicious but healthy life" and insisted that a good balance is needed to achieve an enviable bod, People reported.

Wong first worked with Lawrence in 2010 for "X-Men: First Class." The actress enjoyed her training with Wong so much that she still follows it today.

"We spent 10-12 hours a day together for three months working out between filming on [the 'X-Men'] set," she wrote in the foreword of Wong's new book titled "The Feelgood Plan," as quoted by People. "He changed my body for that movie and gave me the skills to change my life."

In an interview with Elle in 2012, the "Hunger Games" headliner said that she was conscious about "look[ing] fit and strong -- not thin and underfed."

For Wong, who previously worked with Amanda Seyfried and Kit Harington, working with the "Joy" star is also a fulfilling endeavor.

"I met Jen when she was 20, and although I had been doing this for a long time, she helped me figure out how to make a 20-year-old look amazing, but still do 20-year-old things," he told People. "I would say, 'okay, Jen, this is what we have to do. You have to exercise, you have to eat well, but you can go out on a Friday night, and yes, you can have a candy bar.'"

How She Does It

Here are some tips on how you can achieve Lawrence's slim body.

Wong said that Lawrence's food intake is portion controlled, but is sure to give her energy for work, the news outlet added. This constitutes eating the appropriate amount of protein, carbs and fats. Go-to snacks like vegetables, hummus, turkey, dark chocolate, sourdough bread bites and small portions of avocado are what Lawrence eats.

Alcohol is Good Too

Wong also doesn't shy away from alcohol. In fact, he attests that champagne is good for the body because "it comes in a flute and is always in a controlled amount," People further reported. He noted that champagne helps digestion because it punches through fatty foods.

Of course, Lawrence's healthy food intake is made better by exercising. According to Wong, it's important to have regular exercises.

"In between scenes we would squeeze in 15 minutes of exercise -- things we could do on the fly like squats and lunges," Wong shared, as quoted by People. "By taking 15 minutes to do something for your body that makes you feel good. You don't just get an instant lift, you build a lasting change."