If different classes of food have different effects on each person ("One-size-fits-all diets don't work"; Nov 21), then, it substantially reaffirms that dietetics is not a hard science with immutable facts, but a well-meaning and evolving art with lots of gaps in knowledge.

Doctors critical of their patients' diets will now be a little more circumspect and aware that what is sauce for the goose may not necessarily be sauce for the gander.

The report also repudiates the conventional wisdom of "we are what we eat", supplanting it with the fascinating "we are what the bacteria in our guts want us to be".

It seems that humans are, after all, just the instruments of the primitive, brainless single-celled organisms colonising our innards.

Still, this latest research does not seem to contradict what doctors see daily on the ground: That a predominantly plant-based diet of moderation with calorie, dairy and meat reduction works very well for the population as a whole.

For the time-being, it seems sensible to follow what seems to work for most of us, even if one or some of the subjects in the Israeli research study reacted anomalously.

The glycaemic index number of a type of food is only one parameter among a plethora of determinants as to whether its consumption is beneficial to health.

It may also turn out that burnt barbecued meat and processed food may not be cancer inducing, excessive refined carbohydrates may not cause obesity or that trans fats, happily, may not be atherosclerosis generating in peculiar patients harbouring a uniquely health producing flora of bacteria.

Do we dream on or should we take all precautionary measures, based on what we currently know, to safeguard our diets until the imaginary is backed by more detailed and verified research ?

Yik Keng Yeong (Dr)