A voice crying in the wilderness

My pet bugbear is the highly processed ‘civilised western’ diet which has taken hold in the US and UK, particularly over the last 50 years or so. Our bodies have over millennia evolved to consume certain types of foods. The evolutionary aspects of this can be seen to some extent in different reactions to certain foods within different cultures. For example, Western Europeans (and by extension North Americans of Western European extraction) have, over many generations, eaten and drunk dairy products. This is not the case in the Far East, with the observable result that the proportion of Asians who suffer from lactose intolerance is far higher than in Europe. The reason for this is obvious – the lactose-intolerant portion of the gene pool in our society is more likely to have died in childhood in previous generations, and not left any genetic offspring to come down to the present. Hence, lactose tolerance has been selected for in those populations which have a history of dairy consumption.
Now we turn to the issue of the western diet more generally – particularly aspects such as the widespread availability and relative cheapness (compared with previous generations) of meat and saturated fats, refined sugars, refined carbohydrates, etc etc, which characterise a ‘modern’ diet – not to mention ‘artificial’ and highly processed additives. Many of these foods, when introduced to ‘indigenous’ populations, prove highly toxic.
But the point I want to make is, that they are not exactly healthy for indigenous Western Europeans/North Americans either. What are the greatest killers in these countries? Diseases of affluence, such as heart disease and cancers, which can be directly linked to this kind of diet. (Of course, this effect is partly due to the reduction in deaths from infectious diseases etc, because, after all, everyone has to die of something).
Within the population, there are naturally variations in predisposition to these diseases, and also there are other lifestyle factors which also can have an impact. But can we say there has been, or will be, any evolutionary adaptation towards this kind of diet? Well, for a start, it hasn’t really been round for long enough for truly evolutionary effects to appear – a couple of generations, at most. The second point is that the impact of this kind of diet on morbidity tends to come in middle age or later life, after the subjects have already passed on their genetic material to the next generation.
But what is happening now – and this is what I find really interesting - is the rise in diet-linked diseases at a younger age, particularly type 2 diabetes among children and young adults – before they have had a chance to breed.
So, my suspicion is that this is an area where evolution can be seen in action – in that those with a genetic adaptation to toleration of this kind of diet have a genetic advantage – quite a depressing thought, really.