Interesting.. So why are Croatians so tall? o.O What is the standard diet?
Babies.
Just joking.
There's a lot of variety, and different regions have wildly different cuisine. At least when you're talking about the traditional cuisine. And I can say that we (as a nation) eat a lot of meat.
I believe that this increase in human height over the period of last 100-150 years is in direct correlation with that last fact.
Livestock is now treated with all kinds of growth hormones and chemicals which leads to the fact that at least some of those chemicals must remain trapped in our bodies.
That's simply biological magnification.
It takes place in every food chain which is polluted by substances which are either harmful or not normally found in natural environment.
Just take a look at average height of people in India or most of China.
They eat way less meat than Europeans or Americans because of their tradition, religion or other reasons. That might be the reason why their average height is so much lower than ours.
Not excluding the role of genetics.
Which is huge.
I'm just considering this long term exposure to environmental factors.
I didn't get the impression most people were really tall when I was in Cavtat/Dubrovnik... 5ft8 is still taller than me! 
Yes, you are right.
People living on the coast usually aren't as tall as those living on the mainland.
And just to link this to my stream of thought, they don't eat nearly as much meat as we do. They do eat a lot of fish.
