Problem is though, anecdotal evidence does not correct for various things, for example regression to the mean.
The improvement may purely coincidental with the change of diet, or the chosen diet.
Hence we need studies and not anecdata to judge, if something works.
As an individual you should still be allowed to test put various things.
No, as an individual you aren't allow to preach afterwards that anyone can do this.
But you can say: this helped me.
As an individual you don't have to care if it is s result of placebo, your particular gut biome or even magic. If it works it works.
Be happy, write that it helped you, don't write, just don't be annoying about it ;-)
Also the currently top comment https://news.ycombinator.com/item?id=25819790 summarize it neatly, something like: as far as we know all diets work for weight loss as long as we control for calorie intake (but read the original I linked to).
