Dr. Eades replied to my question:

Me: Is there a level of carb intake at which fat burning doesn't occur? Also, is there any data on the amount of carbs in a high fat meal that would cause an unhealthy insulin increase from the incretin effect?

Michael Eades: It's not so much the carb intake as it is what that carb does to insulin levels. If you're insulin sensitive, consuming a bit of carb drives insulin levels up long enough to dispose of the carb, mainly by driving it into muscle. Then insulin quickly drops down and fat burning resumes. If you're insulin resistant, the opposite happens. Insulin goes up and stays up for much longer. If you don't dose with more carbs, insulin ultimately comes back down, and you start burning fat again. But even then insulin never gets down to the level it does in non-insulin-resistant people.

Same with the incretin effect and carbs. People who are thin and insulin sensitive don't have the exaggerated response that those do who are insulin resistant. In those insulin resistant folks, eating carbs and fat provokes a much higher incretin effect.

The take home message here is to develop and maintain your insulin sensitivity.

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