When I first started reading books somewhere in the middle of the last century, it was sort of established ‘wisdom’ that if something was written in a book it was definitely correct. Sort of like many today believe that if it is on the Internet or on TV it must be true.

An important part of growing up was learning that everything in a book was not necessarily right and often far from it. Similarly, as I went through my medical education and training and eventual practice of medicine, it became an accepted paradigm that ‘evidence based’ information was as factual as could be. For us medical sorts facts were of two types, those we produced and reproduced in the laboratory and those that were derived from observations of human responses to environmental factors including diet.

Just about the time I got of medical college, disease of the arteries of the heart was getting to be a big thing. Needless to say, I got swept up in this fervour to fix ‘broken hearts’ and within a decade of getting out of King Edward Medical College, I was a practicing heart surgeon in the good old US of A. And yes that was almost forty years ago. While aggressive young men like me were poking around in hearts and stitching veins and stuff to bypass arteries clogged with fat, the ‘real’ heart doctors were trying to figure out why these arteries were getting clogged with fat in the first place. And it seemed that it was all the ‘fat’ we ate that eventually ended up in heart arteries and clogged them, killing helpless ‘fat eaters’ among us in the process.

Being a heart doctor of sorts, I must accept my own guilt along the way. Even I was swept up in this ‘evidence based’ belief that more cholesterol laden fatty stuff we ate, more of that cholesterol ended up in our heart arteries forcing them to get blocked up. So the word was out. Cholesterol kills, red meat kills, butter kills, eggs kill, even looking at a medium rare marbled fillet mignon could induce a heart attack. So, we suggested restraint. Cut out the red meat we said, cut out the fat, the eggs and almost anything else that makes you feel full and nicely so. But people are people, they asked, but then what should we eat and we said anything but stuff full of cholesterol.

And people ate bread and pizza and pasta and filled themselves up with pastries laden with starch and sugar. And they became fat and developed adult onset Diabetes and because of the Diabetes they developed even more heart artery blockages making the heart doctors extremely perplexed but also very rich. However by now the surgeons like me were passé, it was the heart ‘doctors’ that used to worry about what caused these blockages all those years ago that were now raking in the big bucks putting in metal cages to open up clogged arteries and surprisingly they are now even calling themselves heart surgeons!

And then the truth came out. In the good old US of A, health scientists that made recommendations some forty years ago that cholesterol and fat in diet were the ultimate evil came out a couple of weeks ago with a major mea culpa. Sorry, very sorry they now said (a different set of ‘they’ of course, the original set having probably died from diabetes by now), we were wrong, eating fat in the amounts that most people used to has no effect on heart blockages. Why are they so very sorry, well because they changed the dietary habits of at least three generations of Americans and with it even people in countries like Pakistan where the ‘elites’ like to do whatever Americans do. And it would seem that the recommendation to eat less fat led people to eat more carbohydrates and that led to an epidemic of obesity as well as adult onset Diabetes.

Trying to convert all these obese people back to a diet with more fat but with fewer carbohydrates is totally fraught. These ‘carb’ junkies if told to go ahead and eat fat will start demanding sugary sodas spiked with butter along with their carb laden foods. All dietary advice comes with some inherent problems. First, there is little hard evidence of any one type of diet being better than another excluding extremes on the very low and the very high fat ends. The other major problem with trying to figure out a ‘good’ diet recommendation is that people are different and what might seem good for one type of person might not be appropriate for another.

However, over the last decade, some basic ideas have become established that remain appropriate even with the new dietary information and the new recommendations. I have mentioned some of these recommendations in these columns in the past. Perhaps the most important advice can be summed up in one sentence that I wish I had come with myself. "Eat whatever you want but mostly plants". In other words vegetables, fruits, legumes and nuts should form the basis of any diet. However, protein sources including milk, dairy, eggs and of course meat should also be consumed but as the second most important part of diet.

There is an important point I want to make about consumption of meat. Even though it seems that eating all types of meat is perfectly acceptable from a health point of view, there is a serious problem associated with it. In general as more people acquire the resources to eat more meat, the ‘environmental’ cost of growing the meat will become prohibitive. So it seems that alternate sources of proteins will have to be developed and incorporated into our diets. In Pakistan, we are already approaching the point where most forms of animal proteins are already becoming expensive enough to be driven out of the reach of even much of the ‘middle class’.

As far as carbohydrates like breads, pastas and sugar are concerned; these have been the mainstay in many diets for the last few decades. The basic recommendation is to cut back on all types of carbohydrates especially those that have been ‘processed’ or ‘refined’. When it comes to ‘fast food’ or food that comes out of a box or a can, a simple advice is worth repeating: If your grandmother does not recognise it as food then it is probably not good for you.

All the advice given above applies to those that can afford to eat whatever they want. Sadly for many people in the world including those in Pakistan, it is an ongoing struggle to consume adequate calories every day. Frankly when I tell my cook about what I want to eat, he always looks at me in amazement. He belongs to that segment of our society where getting ‘enough’ to eat is still more important than deciding about ‘what’ to eat. Unfortunately, for most people in this world, ‘enough rather than what’ will remain the primary concern as far as diets are concerned, at least for the foreseeable future.