First of all, Russia now is not NOT Russia during the upheaval and the beginning of democracy. It's a completely different country. Your dd had it EASY compared to the way life was when Yeltsin became president. The months around the fall of the Soviet Union (August 1991) were nothing like most anyone here has ever experienced. The few years following were the most painful the country has every experienced. Thrown into democracy with no experience being democratic turned the country on its ear. Also, I was there as a working adult, supporting myself. I was not a student. Another huge difference.
Secondly, I *didn't* adjust well. It took a year and I became anemic and was undernourished from a lack of variety. I lived off of bread and cheese for the first year. Food was still government issued for a while after 1991. I didn't have access to the foods you mention above. Everything was new to me. Eventually things like pasta became available, but not at first. I was lucky to make a friend in my apartment that started to teach me how to cook. It was cooking like I had never experienced before, and I still had to get used to the flavors. It took a very long time. I suffered for my lack of adaptability.
Nope, I did NOT adjust easily. It was one of the most difficult things I ever did in my life. And it wasn't just food that I had to adjust to. I was a spoiled American. That move really opened my eyes. I've been back since then and Russia is completely different. Life is easy there now. No comparison between when I lived there in the early 90's and when your dd was there. None.
I never said anything about the country being the same - that would be silly - but you, as a working adult, had the ability to shop for and prepare the meals you wanted from the things that were available, limited though they may have been. Rain was there as a dependent child whose only option was to eat what her host family or school cafeteria prepared. Apparently you had regular access to cheese, anyway, which just for the record is something Rain rarely found where she was living last year, and when she did it was a particular kind of cheese that was like nothing she'd eaten before. It's a huge country, and what's happening today in Moscow and Petersburg isn't necessarily what's happening in the rest of it. I know she would have preferred bread and cheese to pasta and ketchup, anyway, and she did come back to me pale as a ghost (her whole group was) and unhealthy. No, she didn't have it easy, in more ways than food, but that's a whole other post.
It seems sort of ironic today that I took her to Tunisia for the next month and she was able to eat lots of good healthy Tunisian food and sit in the sun and get healthy again...
Maybe the real problem is that you went as a "spoiled American" and Rain didn't. She grew up understanding that we do what we can to help people out and make things better for them when we can, and deal with it when we can't. Being sensitive to a child's food preferences doesn't equal spoiling them.
Of course I'm giving our child-rearing techniques credit. But like your ds, my dd did not even want to taste solids until she was over a year old. She was still getting most of her nutrition from BM at nearly 2 yo and didn't wean until she was 4 (although the last 6 months were few nursings far between). She was picky as hell her first couple of years. You are saying your ds has a texture issue. Therein lies the difference. That is not what I would consider to be neurotypical. That's a sensory integration issue. My dd was just lazy - she has no sensory issues. BM is sweet and was instantly available and that was her preference. But once she started eating, I never fed her processed or fast food and the food she ate was not the same thing all the time (and she was exposed to world cuisine from the age of eating solids). Heck yeah, I'm going to give my child raising technique credit. I could have given her crap McDonalds all the time and she would have gotten used to the processed, salty, fatty food instead of healthy home-cooked, from scratch with lots of spices food. She would have ended up picky. The factor of her father's side of the family is that they live in a 3rd world country and have no luxury for pickiness. It has nothing to do with genetics, it has to do with what's available. And again, we're talking about kids who do NOT have sensory issues.
So, what about those of us who offered our kids a variety of foods and didn't do McDonalds and didn't wind up with 4 year olds who enjoyed new foods and would eat anything? Because I'd venture to say that a lot of us fall into that category... and I'm also throwing in a kid who was prone to meltdowns if she didn't eat, so not having a backup food that she would eat would have been basically setting her up for a crisis. I think you were lucky to end up with a kid who eats a variety of food without a fuss, but with one data point it's easy to assume that your good luck is because of something you did.
The thing with most kids in developing countries is that they don't eat a wide variety of foods - they generally eat the same things day after day, maybe changing a bit seasonally but basically the same, because that's what they have available. Actually, some of the aid programs have run into problems for exactly this reason - the food they've brought into countries isn't what the people are used to eating.