Something has to cause evolution all over the galaxy to follow almot exactly the same pattern that it did here on earth, i.e. the universal blueprint for life has to have a lot more in common than just DNA. Six essential amino acids have to be available, to start with. Various vitamins. Compatible sugars and starches. Ascorbic acid (Vitamin C) is pretty much a universal in Terran plantlife, but elsewhere? Conversely, nothing horribly toxic to humans as a universal in the alien planetwide biochemistry.

On top of that, our bacteria and other-world bacteria have to be compatible. That's a tall order. I'd expect that our bacteria would reduce all life on another world to stinking slime, or that bacteria on an alien world would reduce humans to stinking slime, or both of these together followed by a billion-year struggle between two clades of bacteria for supremacy or symbiosis. If our bacteria can't digest other-world life and vice versa, I think it unlikely that us humans could digest the same life.

I think all this unlikely, but for this scenario it has to be true. Panspermia might account for it, or "ancient ones" speading earth-equivalent life across the galaxy in relatively recent geological time, and then transcending the physical. Ok, suspend disbelief ....

You can easily survive two weeks without food, so don't rush. That universal edibility test would do well to start with eating one gram then three grams, ten grams, ... not jump straight from a tiny sample to a quarter-cup (30 grams? )

Also identify something sweet. If no plantlife on this planet offers human-compatible sugar, the best (only? ) hope would be eating animals. Starches, if digestible, turn sweet in your mouth if you chew on them for long enough (amylase in saliva breaks the starch down into sugars).

Also if you home in on a fruit, make sure that there is plenty of it in a less-mature form. It would be a shame to discover that "apples" were safe to eat in "November", when there won't be any more for nine months. Even worse with "raspberries" (they keep less well). Roots are more likely to poison you but far less likely to go out of season.

Obviously as a team, each team member should be guinea-pig for a different potential food source.

On earth you are far less likely to be poisoned by eating animals than plants, because the biochemistry of animals has far more in common with that of humans than the biochemistry of plants. On an alien world, this might not be true, but given the pre-requisite setup above, it is plausble. The problem with a wholly carnivorous diet, is that you eventually run into deficiency diseases. But you would gain time to analyze which plants are least toxic, if finding a highly edible one proves difficult, and you might not need much plant intake to supply the missing trace nutrients.

Something has to cause evolution all over the galaxy to follow almost exactly the same pattern that it did here on earth, i.e. the universal blueprint for life has to have a lot more in common than just DNA. Six essential amino acids have to be available, to start with. Various vitamins. Compatible sugars and starches. Ascorbic acid (Vitamin C) is pretty much a universal in Terran plantlife, but elsewhere? Conversely, nothing horribly toxic to humans as a universal in the alien planetwide biochemistry.

On top of that, our bacteria and other-world bacteria have to be compatible. That's a tall order. I'd expect that our bacteria would reduce all life on another world to stinking slime, or that bacteria on an alien world would reduce humans to stinking slime, or both of these together followed by a billion-year struggle between two clades of bacteria for supremacy or symbiosis. If our bacteria can't digest other-world life and vice versa, I think it unlikely that us humans could digest the same life.

I think all this unlikely, but for this scenario it has to be true. Panspermia might account for it, or "ancient ones" spreading earth-equivalent life across the galaxy in relatively recent geological time, and then transcending the physical. Ok, suspend disbelief ....

You can easily survive two weeks without food, so don't rush. That universal edibility test would do well to start with eating one gram then three grams, ten grams, ... not jump straight from a tiny sample to a quarter-cup (30 grams? )

Also identify something sweet. If no plantlife on this planet offers human-compatible sugar, the best (only? ) hope would be eating animals. Starches, if digestible, turn sweet in your mouth if you chew on them for long enough (amylase in saliva breaks the starch down into sugars).

Also if you home in on a fruit, make sure that there is plenty of it in a less-mature form. It would be a shame to discover that "apples" were safe to eat in "November", when there won't be any more for nine months. Even worse with "raspberries" (they keep less well). Roots are more likely to poison you but far less likely to go out of season.

Obviously as a team, each team member should be guinea-pig for a different potential food source.

On earth you are far less likely to be poisoned by eating animals than plants, because the biochemistry of animals has far more in common with that of humans than the biochemistry of plants. On an alien world, this might not be true, but given the prerequisite setup above, it is plausible. The problem with a wholly carnivorous diet, is that you eventually run into deficiency diseases. But you would gain time to analyze which plants are least toxic, if finding a highly edible one proves difficult, and you might not need much plant intake to supply the missing trace nutrients.