Wow! Now here is something to worry about? What if we can't get a balanced diet? And what is a balanced diet anyways? Where is the balance in all this?
To give credit where credit is due, there are a few truths here. For example, we read: "Did you know that there has never been a single clinical study that documents what comprises a balanced diet, nor one that has demonstrated one's ability to meet basic nutrient requirements through whole foods alone?"
That is true as far as the "single study" goes. It would be hard to design a study like that. How do you measure balanced in any case? Most of what we know about diets comes from inadequacies and deficiencies. Ironically enough, most of those were uncovered when people tried to "engineer" artificial diets in order to improve performance. Deficits are rarely seen in common diets, and only when caloric intake is inadequate. The reason is simple: no diet could survive if it caused illness.
The second part is completely nonsensical. Clearly one is able to meet one's basic nutrient requirements through whole foods alone. That is what people have been doing for tens of thousands of years. More than that, they met their basic requirements and those of their offspring as well. If they hadn't we simply would not be here. The very fact that we are alive proves that our parents ate adequate diets that supported their daily needs for several decades and provided enough extras to produce and raise healthy offspring. Since mammals have long pregnancies that is not a trivial matter.
People in the past also did more physical work and hence put more demands on their diets than we do. No time to sit around on the couch watching TV. No chips to munch on. Nothing but whole foods alone. Real hard labor and long hours were the rule. No pushing paper in the office. No driving kids to school. Survival in past generations demanded a high level of physical fitness.
Studies on Greek triremes, a kind of warship driven by rowers, have shown that the men rowing the ship were every bit as fit as today's Olympic athletes. Given that these were ordinary citizens of Athens, chances are the real Greek athletes were even fitter. All without special nutritional supplements.
Warfare using swords and shields was a physically demanding and exhausting activity. It is widely believed that not too long ago, people walked the equivalent of a marathon each and every day. Pheidipides, the man of marathon fame, ran from Athens to Sparta, a distance of 147 miles through rough terrain, a few days before joining the Athenians at the battle of Marathon. (It is unlikely he ran the 40kms to Athens to bring the news of victory-after which he supposedly dropped dead, but that is another story. He did run the 147 though.)
In any case, my ad-publication tells me "Regular diets simply can't cover the entire range of vitamins, minerals, phytochemicals, antioxidants, and other micronutrients necessary to maintain optimal health and peak athletic performance."
There is every indication that the "regular" American diet, "unhealthy" as it is, does that and more. Clearly it contains ample supplies and lets people grow in all three dimensions. Furthermore, what makes the diet unhealthy is not a lack of items, but rather too much of them. The "regular" American diet is too high in carbohydrates for anyone's needs. But no American eating such diet suffers from lack of vitamins or minerals.
If anything, Americans tend to suffer from hypervitaminoses due to all the vitamin pills they take. They eat too many minerals (esp. salt) and often suffer from mineral deposits instead. They do not lack phytochemicals or antioxidants either.
There is no reason to believe that "daily supplementation is a necessity, not an option," as my publication indicates. Furthermore, the daily supplementation I supposedly need consists of nothing but a cocktail of vitamins and unproven supplements and extracts whose consistency and quality is likely in doubt. Plant extracts are notoriously inconsistent in quality. The levels and types of ingredients vary from batch to batch and from season to season even under the strictest QA provisions. It is one reason FDA shies away from plant extracts.
And when it comes to clinical studies, the news is not good. Not a single study has ever shown the benefit of such extracts. Each and every time people have studied "promising" supplements in prospective studies, the results have been negative or detrimental. Promising cases include those where micro-nutrients were found to be correlated to health benefits in retrospective studies. You heard it all, vitamin E, vitamin C, lycopene, quercetin, etc. etc.
In prospective studies many of these ingredients caused or made worse the very diseases they were supposed to prevent or cure. I would advise you to stay away from such preparations. The benefit is not there and you run a very real risk of ingesting a banned substance without your knowledge. Unfortunately, when that happens you will be totally on your own. Not even a grain of sympathy will come your way.