I don't recall where I've seen such rules, but there are a lot of versions. One point for realism is that men and women of equal height tend to be very similar in weight; men average heavily than women because they're taller on average.
So when building game rules, it's good to start with a height formula, such as: characteristics adjustment + gender adjustment + homeworld gravity adjustment + genetic adjustment + normal curve dice. (By genetic adjustment, I mean that Darrians and Zhodani tend to be tall, some Minor Human Races tend to be short, Solomani are typical, and I don't remember about Vilani. To get a decent normal curve, you need three or more dice; two give a triangle distribution, and one gives a flat distribution.) Once height is determined, the weight formula doesn't need a gender adjustment, unless it's something specific to a particular Minor Human Race.