这BYD还是系列作品是吧

Base +1, itzbrofan +5

The guy becomes younger.
I thought these comics would have the person become always older

Base +6, Na2CO3 +7, Kael Hyun -10, Ion_444 +6, hihihahahoho -8, Gorm +7

I don't know what possessed me to do it, but the mathematics dictate that because the body is shrinking in three dimensions (height, width and depth), it would have to shrink by about 30.7% to achieve three times the density (1-(1/cubic root of 3)), meaning that at an average adult male height of 180cm (5'11") he would shrink to about 125cm (4'1").
This is a lot more plausible that I initially would have assumed, but still a massive height difference.
This does of course not account for pre-existing deviations from the average human bone density in the subject, which would by no means be unreasonable to assume to be an important part of their selection criteria, which may make the difference a bit smaller (or technically larger, but why would they select someone with low bone density?).

Base +6, DoryDope +6, jrgrj206 +6