Stylist Han Hye-yeon lost 20 kg and kept it off — here's what experts say matters most

Stylist Han Hye-yeon has drawn fresh attention to her weight management approach after sharing photos of herself in a swimsuit during a trip to Jeju. Han lost about 20 kilograms over two and a half years and has kept the weight off since, crediting consistent running and careful diet control as her core methods. Experts say achieving a toned midsection requires more than targeting a single muscle group — reducing overall body fat while maintaining muscle through diet is equally important.

Han recently posted several travel photos on her SNS account with the caption "A summer day in Jeju." The images showed her in a bikini and a black one-piece swimsuit, displaying a lean physique. Her toned abdomen and leg lines drew particular attention.

Han shed about 20 kilograms over two and a half years and currently maintains a weight of around 44 kilograms. She has previously cited consistent running, a protein-focused diet with small portions and strict limits on sugar as the pillars of her approach.

On the exercise side, the running Han has kept up consistently is one of the most effective forms of cardio for weight management. Running raises the heart rate faster than walking and burns more energy in a shorter period. Losing weight requires burning more calories than one consumes, and running supports that process.

That said, running faster or longer is not automatically better. Starting at high intensity without adequate fitness puts strain on the knees and ankles and makes the habit hard to sustain. Beginners are better off alternating brisk walking with light jogging, or starting at a manageable pace three to four times a week. Health guidelines recommend at least 150 minutes of moderate-intensity aerobic exercise or 75 minutes of vigorous exercise per week for adults.

Building a defined midsection also requires core-strengthening work alongside cardio. The draw-in maneuver is one accessible abdominal exercise: standing or sitting with a straight back, pull the navel toward the spine and hold for 20 to 30 seconds. Adding planks, dead bugs and bird-dogs helps train the muscles around the abdomen and lower back together.

Abdominal exercises alone, however, will not selectively burn belly fat. Abdominal fat decreases as overall body fat falls. A flat stomach therefore requires cardio, strength training and diet management together — not just core work.

In summer workouts, heavy sweating should not be confused with fat loss. Weight lost immediately after a hot-weather run is largely water, and it returns once fluids are replenished. The risk of dehydration and heat exhaustion rises sharply in midsummer, so exercisers should avoid the hottest part of the day, wear breathable clothing and hydrate adequately before and after exercise. If dizziness, headache, nausea or severe fatigue sets in, stop immediately and cool down.

On the diet side, cutting sugar — as Han has advocated — can meaningfully support weight loss. Han has said she strictly limits sugar intake while dieting and that sticking to that for about two weeks alone can shed 3 to 4 kilograms. Sweet foods and sugary drinks pack a high number of calories into small portions while providing little satiety, making it easy to overshoot daily calorie targets.

In practice, reducing sugar intake can have a positive effect on weight loss. Cutting back on sugary beverages, desserts and snacks also helps stabilize blood sugar and curb unnecessary snacking. Belly fat in particular is linked to a range of lifestyle factors — excess calorie intake, low activity levels, poor sleep and alcohol consumption — making overall dietary adjustment essential.

The protein-focused diet Han emphasizes also helps with weight maintenance. Protein takes longer to digest and absorb than carbohydrates, keeping hunger at bay for longer. It also helps limit muscle loss during weight reduction. Good protein sources include eggs, fish, chicken, tofu and legumes, lean meat and unsweetened Greek yogurt.

Vegetables and whole grains deserve equal attention. Vegetables are rich in water and dietary fiber, providing satiety at low calorie cost, while whole grains raise blood sugar more slowly than white rice or white bread. Rather than cutting carbohydrates entirely, a more sustainable approach is to reduce refined carbs and sugar while eating moderate amounts of sweet potatoes, brown rice and oats.

Avocado is frequently cited as a food that helps manage abdominal fat. Although it is high in fat, most of that fat is unsaturated, and it is also rich in dietary fiber. It can help reduce overeating by increasing satiety, but because it is calorie-dense, limiting intake to about half an avocado a day is advisable.

Ultimately, Han's approach to weight loss is less about any single food or exercise and more about consistent lifestyle habits. Increasing activity through running, prioritizing protein and vegetables, and cutting sugar and overeating all contribute to long-term weight maintenance. Preserving muscle mass, fitness and nutritional balance — rather than simply chasing a lower number on the scale in the short term — is the key to avoiding rebound weight gain and sustaining a healthy physique.