These claims by @RobertLustigMD, @lowcarbGP and many others - claiming starch is the same as sugar - suggests a lack of understanding of the much maligned food science (and of course physiology). https://twitter.com/RobertLustigMD/status/1297062241980694528

Starch is a sugar polymer - but I assume no-one would assume that the primary structure of a protein defines its biological function - indeed, secondary, tertiary and quaternary structures are crucial.

The same applies to starch - the way it is folded, structure in foods...

There's a vast body of literature investigating starch - no-one would assume potatoes and wheat are the same. Fresh and stored starch look completely different:

https://www.sciencedirect.com/science/article/pii/S0308814617300481#f0020

Starch from different foods look (and behave) completely different - and of course the rheological properties are different too.

https://www.sciencedirect.com/science/article/pii/S0268005X12002548

And of course - the biological response is quite different; first, there are huge inter-individual differences, but overall, heated and reheated starch can act very differently.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7022949/

Simplification is of course often helpful in providing an explanation - but it should at least reflect reality a bit.

There is a lot we don't know yet. The behaviour of starch in food processing is a fascinating topic, and there are many ways to influence bioavailability.

So: instead of making sweeping (and wrong) statements, why not try to investigate it further and find new and better ways to prepare & process food?