Absent mass mind uploading, I doubt that food in some relatively recognizable form will ever die out, or that we will ever find it economically feasible to eat food known to be made from human waste. Sunlight and feedstock are cheap, people get squicked easily, and stuff that's stuck around for a long time is likely to continue sticking around. You may as well say we'll outgrow a need for fire, language, or tools; indeed, I'd believe any of those over the total abandonment of food.
Absent mass mind uploading, I doubt that food in some relatively recognizable form will ever die out, or that we will ever find it economically feasible to eat food known to be made from human waste.
Fecal implants do seem to have some health benefits.
There are people who do drink their own urine. Spirilina can be grown on urine.
Algae also have the advantage that they are signal cell organism with means that it's easy to introduce new genes into them via DIY-bio efforts.
That means you can easily change the way the stuff tastes and let it produce vitam...
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