What Bernstein called the “Chinese Restaurant Effect” is now recognized as the incretin effect. I’m not sure it is really well understood but the mere passing of food through the digestive tract causes changes in the signals we now know of as DPP and GLP. These changes would normally cause a secretion of both insulin and glucose. Unfortunately for those of us who a pancreatically challenged only the glucose secretion operates and of course it causes our livers to dump blood sugar a rise in blood sugar even if all we ate was lettuce or water. The incretin effect is used by the DPP-4 and GLP-1 drugs to improve mealtime responses (in both T1s and T2s) and what they do is change this signalling to be less dysfunctional.
In my opinion, this effect is real and we should think of it as one way the incretin effect manifests itself.
ps. And I have personally observed larger than expected blood sugar rises with large quantities of low carb food.