i'm 172 cm and 80 kg how much weight should i lose?

Answer 1

An easy way to figure out is: your height in centimetres minus 100 - so for you 72 kg would be in the mid range

however this is only mid range - you would still be healthy weight with a few kilos either side

try BMI (body mass index) = weight/height (m) squared - should be between 20 to 25