Sung Si-kyung Lost 10kg, Then Picked Up a Burger — Here's What He Said About Ads and Integrity

Sung Si-kyung has one of the most recognizable voices in Korean ballad music — a rich baritone that has been a constant presence on pop charts for more than two decades. But in recent years, he has built an equally devoted following through an entirely different medium: a YouTube food channel called 먹을텐데 (I'm Going to Eat), where he visits restaurants, eats with visible enthusiasm, and talks. Not about music. Just about food, and life, and whatever is on his mind.

On March 30, that combination produced a moment that's been circulating widely. Sung Si-kyung visited a burger restaurant for an advertising shoot — his first ad in a while, by his own account — and somewhere between bites, explained why his channel doesn't have more of them. The answer turned out to be more interesting than expected.

The Principle Behind the Plate

"Ads come in a lot," he told viewers, with characteristic understatement. "I'm just the one rejecting them."

That sentence has been doing the rounds among fans since the video dropped, partly because it contradicts the obvious assumption — that a celebrity in Sung Si-kyung's position would want as many brand deals as possible — and partly because it reflects a principle that viewers of 먹을텐데 have suspected was operating in the background for a while. He only promotes things he has actually used and genuinely feels comfortable recommending. That's the filter. And it's a tighter filter than most advertisers prefer.

The practical consequence, as he explained it, is that potential brand partners sometimes walk away. An advertiser wants certainty that the partnership will happen before they invest time and resources in it. Sung Si-kyung's process — try the product, evaluate it, then decide — introduces a variable that not everyone is willing to work with. The result is a channel that runs light on advertising compared to what his subscriber count and engagement would typically support.

It's worth noting that this isn't a purity narrative about rejecting commercialism. He's happy to work with brands that clear his bar. The burger restaurant visit was itself an ad shoot, one he clearly enjoyed. His point is narrower: that the standard he applies means some opportunities don't survive contact with reality, and he's comfortable with that trade-off.

The Diet Story That Made Everything Funnier

The contrast between Sung Si-kyung's current posture around food and the circumstances that brought him to his previous high-profile ad deal made the video land with particular humor for fans who had been following the story.

Earlier this year, Sung Si-kyung was signed as a model for a cosmetics brand — a somewhat unexpected booking for a male ballad singer in his forties, and one that came with a specific requirement. He needed to lose weight. The diet he described in the March 30 video was legitimately demanding: eggs and sweet potato during the day, raw fish with half a bottle of soju at night, an hour of walking and running every evening, and three separate workout sessions on shoot days. Over the course of the campaign, he lost 10 kilograms.

"I never want to diet again," he announced, sitting with a large-format burger in front of him. The line landed as the kind of declaration that requires context to be funny, and his audience had the context. Someone who spent weeks on eggs and sweet potato, looking at this burger while running through a half-marathon training schedule, has earned the right to say it with feeling.

The cosmetics campaign itself became a talking point — not because of controversy, but because the images of Sung Si-kyung looking significantly leaner than his usual self prompted genuine reactions from fans who found the transformation striking. The diet was, by his account, worth it for the shoot and immediately not worth repeating after it.

Why the Food Channel Works the Way It Does

Sung Si-kyung's YouTube channel has accumulated a loyal following that extends well beyond fans of his music. Part of that appeal is specific to 먹을텐데's format — the combination of genuine enthusiasm for food, a conversational tone that doesn't feel managed or calculated, and the sense that whatever comes out of his mouth is reasonably close to what he actually thinks.

That last quality is what makes the ad philosophy story feel consistent rather than surprising. If you've watched the channel with any regularity, you already know that Sung Si-kyung will eat something, describe it accurately, and tell you whether he thinks it's good or not. The same standard applies to what he's willing to put his name on commercially. Viewers who watch him eat honestly tend to trust that he recommends things honestly too.

This isn't an unusual dynamic in the broader landscape of creator-brand relationships, but it's less common in the specifically Korean celebrity context, where the line between genuine endorsement and paid promotion has historically been less visible to audiences. Sung Si-kyung's explicit articulation of his own filter — "I eat it first, and if I like it, then we talk" — adds a layer of transparency that audiences respond to even when they don't consciously register why.

What Comes After the Burger

Sung Si-kyung's music career continues alongside the YouTube activity, with his ballad catalog remaining a staple of Korean broadcast and streaming platforms. But increasingly, 먹을텐데 functions as its own entity — a content format with its own rhythms, its own recurring segments, and its own relationship with viewers that is distinct from the artist-fan dynamic his music career produces.

The March 30 episode demonstrates why that channel works at the level it does. A burger restaurant visit, an ad booking, a diet backstory, and an honest explanation of his commercial standards — none of it is dramatic, none of it is designed for maximum virality, and all of it is exactly what the channel's audience shows up for. The combination of the mundane and the authentic is, it turns out, a reliable formula.

As for the diet: Sung Si-kyung has declared it finished, permanently, with the kind of conviction that someone earns by actually completing one. Whether that declaration survives the next major career opportunity that requires it remains an open question. But for now, there's a burger in front of him, an ad deal he actually wanted, and a principle intact. That seems like a good day by his standards.