You are absolutely right that we all differ, neohdiver, and one size most definitely does not fit all.
It seems that our hormone reactions to different nutritional elements within our diets vary, and what suits some people really well will have much less positive effects for others. Whether it will in the end prove possible to research and define ‘most likely to succeed programmes for the majority of the population’ remains to be seen. However, I am convinced that reducing at least one refined carbohydrate, i.e. sugar, is likely to be generally beneficial to most people.
Part of the difficulty is of course carrying out large enough tests over sufficient duration, and then long-term follow-up research. One can only hope that such experiments are in course of action, whilst we continue not to teach doctors or nurses much about nutrition, even that there are alternatives which may be worth trying.
On another thread here I described how on a routine visit to my doctor I described what I had been doing, and told her about the research being carried out by Professor Taylor at Newcastle, which lay behind the BSD. I said that it might be worthwhile her investigating (especially as OH has now been able to come off metformin) and she held her hand up to stop me, saying “I might recommend it, but I simply don’t have time to investigate it”. I greatly regretted not taking her up on that astonishing statement, and asking whether she and the rest of her partners did not have sufficient Type 2 patients to investigate (either personally, or via their nominated Diabetes specialist) what might be a possible treatment for them. One of those wake-up-in-the-middle-of-the-night moments, kicking yourself for not saying what you should have done.
But very best wishes to you for your ongoing (and well-researched!) journey.