People are always nobbling the dietary guidelines suggested by a professional.But the actual diets are given considering the health benefits for heart health ,dental health,etc.
We have all been led to accept that these scientific studies are hard and fast evidence. They are not. The problem with the epidemiological studies is that they are observational studies called prospective studies, which means they are exploratory looksee to find if there may be grounds for further research, They find possible linkages and interactions between aspects of the diet, but do not establish the cause. For nutritionists this is ample 'proof' of causality, and they reach binding conclusions based on weak and flimsy associations that could easily be due to other factors not considered or measured by the study.
So starting with weak data, the authors of the reports apply statistics to make the connections. Now I have used their statisical methods myself, and the first part of the process is to sit down and draw up a list of things that could influence the outcomes. Those considered to be most important are given the most weighting, and from this list the data is manipilated by applying rankings. Now there is no requirement to state in the report what weighting factors are being applied, or why, so different groups analysing the same data set will probably reach different conclusions, and there is no means of back analysing it either. It is this methodolgy that allows interested parties to influence the outcome by nobbling the panel used to set the rankings, and the importance applied to different aspects of the research. In 2006 there was a move to clean this up, and the analysis method known as PETO was banned for new studies since that date. However, meta analysis using the older data still is affected by the previous reports that remain unworked. Ranking is still being applied by the replacement analysis tools and still open to massaging.
The other problem is that most of these studies are devised, executed, analysed, then peer reviewed and published by the same small team, without independant review. Their raw data is kept locked away from prying eyes as being commercially confidential, and to cap it all the funding for the studies or the team working it are all from interested parties. For example, many dietary studies are funded and executed by Barilla or Wellcome or by universities and research labs belonging to them (i,e, Harvard T Chan, Lindy Loma, Utah State Uni, and now it seems Oxford Martin). The current EAT Lancet report is a classic example of this.
Sorry, I can no longer live in a dream world or assume Utopia is here,
