After a lecture a man asked me why I do not recommend a paleo-type diet although I said during the lecture that it's usually a very healthy diet - and his opinion was that I was promoting a less healthy diet when allowing many things he didn't. Why do I "allow" eating food for which the health effects are minimal or even unhealthy- say a potato? Well I used paleodiet just as an example as it is by no means automatically healthier than any other diet type. And the main question is that how healthy diet should we pursue. If I consider my usual advice it would be easy to say that one could eat more healthy diet. Eating advice could always be healthier, and even healthier - and still healthier. But it's not a good idea to chase the optimally healthy diet.
Naturally I want people to heat healthily and I'm sure my advice leads to a healthy diet - but it doesn't mean everything has to be healthy. Why don't I optimize? Very shortly put I could say I aim for well-being and health is only one block of many in that set. And if some other block (taste, social flexibility, stress-free eating etc.) needs more space to attain better well-being health can easily lend some of that space. This is certainly a common sense argument that many already know. But there are other reasons..
How healthy is healthy enough?
Another reason is that saying what is a healthy enough diet and what is not is very much a thin line that can be drawn anywhere. It's simply an opinion, not a fact. And the line has to be drawn somewhere because it is utopistic to as healthy as possible because neither science nor any person has an idea of the optimal diet - and if they claim they do they don't know enough. How so?
For example is my discussion with the older man followed some variety of paleo diet and called it an optimal diet. It was easy to counter that it might be slightly healthier than what i outlined in my lecture but is surely is not optimal: did he gnaw bones? Eat insects? Etc... and thus getting rare nutrients - such as glucosamine - that our usual diet doesn't contain. Of course he didn't and of course the diet wasn't optimal. And even if he did there would have been countless other issues that knowingly or likely improve health: Did he eat most food raw? Surely there wasn't added salt anywhere?.. There is no end to these questions and in fact his diet was not optimal. And I'm pretty sure no one other on this planet eats an optimally healthy diet because none of know our genetic makeup and thus not the optimal diet for it. The man had just drawn the line in a slightly different place than i had. More on the health side, less on the flexibility and taste side in his case (he did say having some problems in these). It was neither right nor wrong, it was just his choice.
Then there's also the fact that there is a name for trying to as healthy as possible - orthorexia. While working with eating disorders it is quite obvious that there is a limit to how healthy you can try to eat before thought patterns and practices associated with disordered eating start growing.
Then there are all the other lifestyle factors. Theoretically, if we aimed at optimal dietary recommendations we should - in all fairness - aim at optimal recommendations in other aspects of life too. What would be the point of spending energy on eating as healthy as possible while sleeping too little and being too inactive - I don't see one. That's when things get really complicated. Aiming for "optimal" physical activity (..naturally not really known either..) would surely mean a lot more activity than the present recommendations of 30-60 mins a day. Here in Finland, 2/3 of population doesn’t make even the 30 mins a day and i still remember the cries of disbelief when the upper limit of 60 mins was established some years ago: unrealistic!! we have a life u know!!.. But a total amount of around 1,5 h activity a day would likely be needed. And that's just the amount and as to the quality it would need to be adjusted to cover all the aspects of motor function, flexibility, aerobic fitness etc. while still taking care to avoid injuries. And that's just exercise - add to that recommendation of optimal sleep, stress management, dental care, ergonomy... Noooo, I really don't want people to strive for optimal!! They do have a life u know!!!
The point is that whatever we recommend it is never optimal and it is always just a question of where we draw the line of "healthy enough". Even during the times of evidence-based medicine, all recommendations and guidance is very much a product of opinion and especially opinion about what is realistic and feasible. So it is with eating too. You can make it healthy and easy.. or healthier and bit more difficult..or very healthy and very difficult (and possibly also unhealthy in the end). For example the present recommendation of eating veggies, fruit and berries is around 400-500 g day in Finland and likely around that number wherever you are. Of course 400-500 g a day is not the optimal intake and more is better - but Finns happen to eat around 350 g a day so it’s a realistic goal. Surely the optimal intake is somewhere with 4-digit gram figures but few dare to set those goals. Which is fine by me - I usually recommend just going over 500 g a day.
Line has to be drawn somewhere even though no thresholds exist
So the idea is clear. Lines have to be drawn and some balance between healthy eating and feasibility has to be found. Recommendations draw this line somewhere and individual people may draw it elsewhere. Whenever you see any general recommendations it is worthwhile to consider whether you share the same ideals as those giving recommendations. If you don't want to make any bigger fuzz about eating there are likely recommendations you shouldn't mind about. And if you want to eat really healthily the recommendations are just the starting point.
Then there's also the question of how much are you willing to do just based on speculation - when something MIGHT be healthy but then again it might not. When we just don't know - organic food for example? I'm quite sure most people do not want guidance based on speculation and I would leave these things to more devoted healthy eaters and not recommend it to all. But then again there are many who are willing to go far to the zone of unknown - that's fine, just don't expect others to follow.
People vary on how much they are willing to put emphasis on the health aspect of eating and that's fine. I just wish people would stop trying to eat as healthy as possible because the concept in itself is an unreachable, utopic dream - and while chasing the dream the payout diminishes the further you go. With a poor diet you get huge benefits with small changes, with a very good diet to start with it is debatable what gains there might be to improve it further.