I am Dutch and tall too. Way taller than my parents. However, I always suspected it has to do with things like growth hormone in meat instead of fresh food.
Growth hormones have been banned in the Netherlands since 1961 and usage wasn't widespread beforehand.
I agree, there probably are specific foodstuffs in our diet now (such as dairy & meat) that cause growth above other foodstuffs, but these have become more affordable across the board due to "early-access" availability in the distribution chain (with a major component of that being the port)
I am of Dutch descent, but I have never set foot in the Netherlands. Somehow, though, I am much taller (6'1) than my dad and his father, who were both pretty short (5'2).