Alternatively, I think the idea that outside some extremely broad parameters (not eating a diet lacking essential vitamins, under-eating to the point of malnourishment or over-eating to the point of severe obesity, etc) there are no particular nutritional needs is under-examined.

Nutritional Science seems based on the idea that relatively minor tweaks to diet can influence health outcomes. After several decades of failing to find what those tweaks might be, it always seems strange to me that people don't seem to consider that they might just not exist, and that the human body is fine with whatever food it gets, within some broad range.