[Question_Assumptions]

I didn't say that a better diet is making us taller. I just said that a different diet is having that effect. Considering the obesity and heart issues so prevalent today that didn't exist 100 years ago, I seriously doubt that we have a better diet today.

Well, if you want to debate whether our diet is "better" or just "different" in a broad sense, knock yourself out. But with respect to having enough calories and protein as children to reach our our biologically maximum height, our diets today are better. That the diets in many Western nations (and particularly the United States) far exceed the amount of calories and protein that we need to reach our biologically maximum height resulting in obesity is a different issue. My point is simply that many populations that were once considered genetically short were actually short because of nutritional problems, not biology, and given plenty of protein and calories, the children of people in those populations can grow quite tall. If you want to argue that we've exceeded the point of improvement and headed well into overconsumption causing a different set of problems, I'd probably agree with you.

[Frumious Bandersnatch]

The diets in the U.S. from before the inception of the nation was more than sufficient to support what we needed as individuals and then some. That's not to say it was necessarily equally distributed (it rarely is). Nor does it say that there weren't cases of malnutrition.

I do agree with your point about peoples not reaching their full biological potential due to the lack of sufficient nutrients. I've noticed, however, that there is a tendency amongst some to put this down solely to natural selection rather than a change in diet.