With every 1 kg/m^2 increase in BMI your SH/H changes by about 0.01, which should be useful to those concerned about sitting height like me, so working your butt off can maintain your ratios to still somewhat normal. Minimum should be about 0.49 and no less to not look outlandish, closer to 0.51 optimally.
So like in my case, with a 21 BMI I could add 2 kg/m^2 to be around 23 and my SH/H would be nearly 0.53 which can make my goal of 175-178 cm more realistic than my 85cm ish sitting height as of now to be nearer 87-88 cm of it.
Read this a while ago, forgot the source.