I grew up and live near D.C. at present (near the 2nd or 3rd largest Korean population outside of Korea after L.A. and maybe NYC depending on how you count). I've been back and forth to Korea about a half dozen times over last 13 years and have noticed the trend there as well (I'm not Korean, but my wife is).

My in-laws (Korean) are all talking about how hard it is to get kids to eat the kinds of foods they grew up with: salty, spicy, fermented (and generally pretty nutritious), and instead their kids are dead set on eating what they call "American foods" like hamburgers and pizza. Their parents complain about having to tone down certain strong flavors and ingredients in order to get their kids to eat the food at all.

I don't think it's quite as bad as they say, but I and my extended family in Korea have all noticed a rising wave of both obese kids in Korea, and much taller kids than any previous generation.

For people of my wife's generation, I'm usually near the top of the height range for any random selection of people (I'm 5'9"). For those same people's kids, by the time they're in high school, they're usually a few cm taller than all of us. I can really only think of a couple kids who didn't at least reach my height, but at least half their parents are shorter than me.

Because I've managed to cultivate a taste for the more old fashioned flavors, people are frequently pretty surprised at what I'll eat. I've even sat by sheepishly while a mother severely scolded her son for not eating traditional Korean food as well as this foreigner. People say I eat Korean food like an old ajusshi if that makes any sense to you.

As the default hangover cure, I've had lots of this soup both here in the U.S., but mostly in Korea. You can still find it made the old way, usually in pretty spare looking old restaurants from back in the 70s or 80s. Newer places never seem to have it with the blood.