Think this recent article from the UK’s Guardian newspaper qualifies as QS appropriate.
Not least because of the academic rigour that the author — not me — put into his study.
Should say that I am not a vegan but an omnivore and have not been swayed by his personal results from an N of 1 study however his meta approach has merit for all of us who undertake our own quantified self programmes.
Thats a good example of QS study, but there are not too much quantitative measures. He didnt measure caloric intake during both periods, and it might be that during vegan diet he just eat less calories and this is why he lost more weght, leading to a false conclusions. Also him drank more alcohol (more than half of days, wow) during non-vegan period. As we know alcohol have some calories and size of portions is unknown, so there are too much uncertainty in results and his data, results in weak final conclusion.
Anyway its good to look it examples like that when you design your own QS experiment.