at all intensities? no. diet won't manipulate the percentage of fat used at high intensity, because we know fat isn't used at high intensity. the only thing a change in diet would do is determine the duration at which you can hold that high intensity due to sufficient, or not sufficient, glycogen storage.

thanks for the read, it's been known for quite a while that fat loading does not equal a performance benefit, as stated in the review (from 2006)

and by the way, i agree whole-heartedly with you saying you can't teach your body to burn more fat.