Koreans are obsessed with "health." Diet, exercise---it's a daily part of Korean culture. Outdoor gyms (which deserve their own article later) can be seen at apartment complexes, city parks, and at the tops of Seoul's many mountains. My students constantly chat about body shapes (which, again, need their own explanation). Perhaps their greatest concern, though, is healthy food.
Me: [eating crackers at my desk at work] Mr. Lee: [looks at me without saying a word] Me: Uh, hi, Mr. Lee. Mr. Lee: I heard on the news that these [crackers] are not good for health. Me: Oh really? What makes them unhealthy? Mr. Lee: I don't know. I only heard they are not good for health.
By hearing crackers (mine were unsalted soda crackers, by the way) are not "good for health," I'm pretty sure that Mr. Lee---and anyone else who watched that news program---will never eat crackers again.
They have nothing to worry about, though, because any Korean will proudly tell you that they have the healthiest food in the world.
When I first arrived in Korea, my co-workers kept telling me that kimchi, a fermented cabbage (or other vegetable) dish, was one of the top 5 healthiest foods in the world. I kept laughing it off, thinking, Okay, it's healthy. But it's not like there's an official list or anything. But ask a Korean, and they will tell you there is.
Health magazine published an article listing the "World's Healthiest Foods" a few years ago and kimchi made the cut, along with lentils from India, yogurt from Greece, Japanese soy, and Spain's olive oil. The magazine attributes its "healthiness" to its large doses of Vitamins A, B, and C, as well as it's "healthy bacteria," lactobacilli.
Most Koreans eat kimchi with every meal and attribute their personal health to this dish. In fact, I was told that Korea did not experience a SARS outbreak because of kimchi. "Kimchi kept Koreans strong," I was told.