I've found that turning up the burner all the way simply sends a lot more flame up the side of the pot instead of onto the bottom. Halfway seems to be more efficient. That's especially true with the narrow 550 ml pot I use for solo trips. I haven't, however, tested this out by weighing the canister, which I should.

I still haven't caught a fish to be able to measure how much fuel is needed for fish frying, either. My grandson had no luck, either, on our recent trip.
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May your trails be crooked, winding, lonesome, dangerous, leading to the most amazing view--E. Abbey