it is always better to follow the opinion of scientists and professors in text books of medicine , or some websites which are reliable.
which are these reliable websites ?
1]the NIH of USA [ada being their advicers]
2] the WHO guidelines
3] the Harvard medical school '
diabetes uk, mayo clinic and so on .there are many in this group.
web md ,e medicine etc are sites which
give more information quantity-wise,
but authenticity and being up-to-date, the above given 3 are best in my opinion ,because they always are presented by a panel of professors and edited, revised ,every now and then.
[they carry better information than a text book of medicine in some restricted sense,, the text book which is always at least 5 years delayed when it reaches you and , the ideas are of one professor only ,the one who authored it]
remember we know only English , there are not many English speaking countries.
USA,UK,Canada, Australia and Zealand -over.,only five.we have no other option but select from them.