My knowledge on nutrition and biology is elemental at best, but the following insights have taken my attention in the last days and have made me think of the topic of nutrition and the concept of "health".
First of all, there's an increasing awareness in society and media on what we eat and how it affects our diet and health. I believe that being aware of what we do -specially on things we often do compulsively like eating- it's really beneficial as we have an attentive way of life and raise perception on all internal and external factors of our actions and how they impact the world. For instance, factory farming solves the problem of feeding a large and very concentrated population, but industrial raising and slaughtering of animals brings them a lot of stress and suffering which in turn results in a high toxicity in the meat we eat, ending up in all sorts or diseases and ailments.* But there's a distinction between awareness and obsession, and I believe that for some people, their seek for "healthy food" has became the latter. Take for example this family [spanish only] or this article on the topic. While it's reasonable for a parent to pay attention to her children eating habits and intake of unhealthy food, I do believe there's a problem when you try to detoxify your children after one of them ate a single marshmallow.
Not only obsession for healthy food has been around, but also unhealthy means to get a good shape or weight. There's a rapidly growing industry of "healthy living" everywhere, and naturally aggresive marketing campaings to sell diet books, workout programs, organic products, etc. With so much propaganda, It seems like being healthy is becoming a new XXI century obsession, specially where no accurate information is available.
With it's shocking experiment "The Twinkie Diet", Professor Mark Haub has raised many interesting questions about the topic. Having lost 27 pounds without getting higher cholesterol or triglycerides levels by eating only Twinkies he know asks, "What does that mean? Does that mean I'm healthier? Or does it mean how we define health from a biology standpoint, that we're missing something?". Of course, Haub is not suggesting that the Twinkie Diet is healthy, but when it comes to only lose weight or have certain measures low, what does it mean to be healthy anyways? As he suggest, we need to revise our definition of what does it mean to be healthy.
When I think of somebody healthy, it comes to my mind factors such as resistance to illness, strength, physical energy and a good hair, skin and teeth appearance. And while many people suggest a diet based on vegetables or at least a balanced diet of all alimentary groups, it was surprising to find in one of my readings about Genghish Khan and his warriors that one of their advantages in comparison to rival armies was how healthy and strong was a Mongolian soldier: strong teeth and bones, not prone to illness, quick to heal wounds, and easily able to ride and fight for two days in a row without food. The secret of their diet? Only milk and meat.
I'm not suggesting that vegetarian or other diets are unhealthy (just as with the mongolian, you could also find examples of vegetarian people who have extraordinary health) but my point is, when talking about diet and food, what does really mean to be healthy and what are the means we are following to be so?
tl;dr: "healthy food" as perceived by some people, does not necessarily mean a healthier body.
*This is a very well known relation but there are many more, like the dissociation of city people with animal life and nature, where people no longer consider animals as living beings and rather treat them as objects. This dissociation can take up the form of cruelty and brutality toward animals, and in sever cases, scales up to psychopathy affecting other human members. Authors like Desmond Morris have explored this issue when dealing with violence in societies.