I have for many years eaten no meat, fish or seafood and I’ve never taken any protein supplement.
There is plenty of protein not only in lentils, beans and such but also in grains as as well as in other seeds. Even leafy vegetables contain protein. But sugar and oil do not.
Depending one one’s tastes and habits, it’s certainly possible to fail to eat enough protein but the challenge for adults eating no animal products but who can afford a reasonable diet and have no special needs is not so much to reach an adequate total protein intake but to eat enough of every type of protein. Soy seems to be helpful in that regard (as well as contributing nicely to one’s total protein intake).
From the abstract you linked to:
“none of the six epidemiologic studies identified provided any evidence that soy intake was associated with circulating uric acid levels”
“on the basis of the existing data there is no reason for individuals with gout or at risk of developing gout to avoid soyfoods”
Which is of course not to say that soy doesn’t make any difference but it certainly seems like it usually makes little difference when consumed in moderation.
As with many other foods, there is however a risk involved in eating too much of one thing, especially if you have a health problem such as gout. The risk is of course much greater when consuming extracts, powders and other supplements.
Did your doctor tell you why you should be taking Feburic at breakfast?
Others might be interested to know because that’s not what all doctors recommend.
It’s good that you are planning to monitor your uric acid in the future. It’s better to have the test too often than not enough.
And since you are experiencing a variety of symptoms, the next time you see your doctor you might also want to ask about the various drugs which only help with the symptoms. Trying such drugs when you are having different symptoms might help you and your doctor to determine if they are likely to be caused by the same thing.