This will affect your top end HP if you care, but shouldn't affect part-throttle low-to-mid range torque, and will make it easier to maintain and modulate smaller throttle openings for better fuel economy: Fit a smaller diameter throttle body.
If you still want that top end, you could do something creative to get that full-throttle intake opening. Dual throttle bodies with progressive linkage (Some early FI VW's used such an arrangement), or even a simple secondary intake tube that bypasses the TB with some sort of solenoid valve that pops open at WOT. (which, I guess would be a sort of progressive dual throttle body of sorts)
You could also futz with the TB linkage. Instead of a round cable pull on the throttle shaft, some sort of egg-shaped or off-center arrangement that would make the first half of the throttle-pull turn the throttle plate less, and the second half turn it more. Progressive throttle. I know there are aftermarket kits for some cars that make the throttle more responsive, this would be the opposite of that.
Anything you can do that will keep you from opening the throttle too far and "accidentally" using excessive fuel would help to improve fuel economy.