The Actress Opens Up About the Intense Physical Transformation Behind Her New Role

Preparing for the Role of a Lifetime

November 14, 2025: Sydney Sweeney is opening up about the dramatic body transformation she underwent to portray champion boxer Christy Martin in her upcoming film Christy. The actress revealed that she gained 30 pounds for the role — a process she described as both challenging and eye-opening. HOLR breaks down her surprising method for achieving the weight gain.

A Fast-Food Diet Designed for Muscle and Mass

To authentically embody the legendary fighter, Sweeney explained that she followed a strict weight-gain plan that surprisingly involved fast food. Burgers, fries, milkshakes, and calorie-heavy meals became part of her daily routine as she worked with nutritionists and trainers to safely increase her body mass while building the physicality needed for the role.

Training Like a Champion Boxer

Alongside her high-calorie diet, Sweeney spent months training like a professional fighter. Her schedule included boxing drills, strength training, sparring sessions, and endurance exercises. She noted that the fast-food diet wasn’t meant to be glamorous — it was simply the most efficient way to rapidly fuel her body for the demanding workouts.

Honoring Christy Martin’s Story

Sweeney emphasized that undergoing this transformation was her way of honoring Christy Martin’s journey. The actress has spoken highly of the boxer’s resilience and wanted her portrayal to feel grounded, real, and respectful.

Fans Praise Her Dedication

Following the reveal, fans flooded social media with support, applauding Sweeney’s dedication and willingness to fully immerse herself in the character. Many praised her for taking on such a physically and emotionally intense project, further boosting anticipation for the film’s release.