South Korean actor So Ji-sub, the 47-year-old “melancholic-eyed” oppa loved by fans for nearly three decades, is back in the spotlight through his role as Nam Gi-jun in the Netflix series Under the Red Moon, where he portrays a man seeking revenge for his brother’s murder. What really caught everyone’s attention, though, is the incredible physical transformation behind the role — So Ji-sub dropped 19 kilograms in just a few months, going from 95kg back to his signature tough, masculine physique. According to media reports, his dramatic weight loss came down to one thing: iron discipline. He cut out three specific foods and committed to daily squats, no exceptions. Experts say this combination of selective eating and consistent exercise not only speeds up weight loss but also reduces the chances of regaining fat.
So Ji-sub’s Diet Rules: No Alcohol, No White Rice, No Salty Foods
A former competitive swimmer who entered the entertainment industry as a model, So Ji-sub has long been adored for dramas like I’m Sorry, I Love You, Master’s Sun, and Be With You. When asked about his quick weight drop, he revealed that he’s no stranger to losing weight for a role — every time he starts a new project, he manages to slim down rapidly through food restrictions and disciplined workouts.
During this transformation, he avoided three things completely: alcohol, overly salty foods, and white rice. For protein, he focused on seafood and lean white meat like chicken. And when he got bored, he simply changed up the seasoning or cooking style to keep meals enjoyable.
His Go-To Exercise: Daily Squats
Media outlets report that So Ji-sub swore by nightly squats throughout his weight-loss journey. He believes doing squats before bed strengthens the lower body, boosts metabolism, and even improves sleep quality. And just like anyone else, he struggled with motivation — skipping exercise for even one day immediately showed up on the scale. By keeping himself accountable every single day, he worked his way from “uncle bod” back to action-hero form. On screen, every punch, every step, every stare in the drama carries that intense physical presence.
Nutritionist’s Take on His Method
Nutritionist Chao Han-ying says men generally lose fat faster than women because they naturally have more muscle mass and stronger metabolism. Combined with So Ji-sub’s consistent mix of weight training and cardio, his results were amplified.
She highlights what he did right:
- Don’t skip healthy fats: The body needs essential fatty acids for proper metabolism. Extra-virgin olive oil, flaxseed oil, and nuts can help burn fat more efficiently.
- Cutting alcohol is crucial: The body prioritizes metabolizing alcohol before burning fat, slowing down weight loss. Avoiding alcohol helps both men and women slim down faster.
- White rice and salt don’t have to be completely banned: Swapping white rice for fiber-rich carbs can stabilize blood sugar and reduce cravings. As for salt, avoiding high-sodium processed foods and not over-seasoning is usually enough to reduce water retention.
Different Strategies for Men and Women
The nutritionist also reminds readers that weight-loss strategies differ between men and women. Men often respond well to exercise plus diet control, while women face hormonal fluctuations, water retention, and emotional eating. Women’s plans should include stress relief, cycle-based nutrition adjustments, and personalized tailoring to their body condition.
As for So Ji-sub, his method fits male fat-loss logic, but not everyone can spare hours for training every day. She suggests adjusting diet based on realistic exercise habits. Women who want to follow something similar should consider their physical condition, emotional patterns, and whether they can handle intense workouts — personalization is key to a healthier, long-lasting transformation.
