Brief correction:
the cited articles of Collier show that adding some fat to a carbohydrate
meal actually decreases insulin levels -but only very slightly, much less
than it decreases blood glucose levels.

There have been other studies concerning the adverse effects of combining
fat and carbohydrate, like
Collier GR. Wolever TM. Jenkins DJ ., Concurrent ingestion of fat and
reduction in starch content impairs carbohydrate tolerance to subsequent
meals, Am J Clin Nutr 45(5):963-9, 1987.

Overall, it seems that the only advantage of combining fat and
carbohydrate is that it stabilizes blood glucose levels, and satisfies
hunger more; but the effect on insulin is almost zero, and moreover
carbohydrate tolerance on subsequent meals is impaired.

Best wishes,

Jean-Louis
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