I actually think class should be taken into consideration as well.
Generally speaking, for muscle mass it should go warrior > rogue > mage, regardless of race or gender, and muscle mass is a great factor in weight. I fully expect Krem and Cassandra to have very little body fat and be able to physically wipe the floor with my puny human fem mage Inquisitor.
Of course, the caveat has to be made for roleplay by saying that the player can choose to have their character be as buff or puny as they want.
And no, you can NOT take the cutscene bodies into account. As great as the shot of Dorian is (reference link, for science), people need to get it through their heads that Dorian, Cullen, and the human male Inquisitor all have the SAME body (except for skin tone). This means no differentiation in muscle mass or body hair. While the use of these same bodies is understandable from a developer POV, I really don't feel that players should use that as any sort of factual basis for what the character's body actually looks like. (This actually allows for a bit of freedom in fanfic writing.) The exception for this would be for characters like Iron Bull and Isabela who have unique body shapes due to their characterization.
Back on topic... my canon Inquisitor is a human male warrior, who, as stated above, I fully expect to have a decent amount of muscle mass due to his being a warrior. I also tend to feel that he is over 6 feet (1.8 meters) tall**. However, I really don't have any reference for how much a muscular man of that stature would weigh.
So... tl;dr is I have no idea.
** I haven't settled on an exact height, primarily because I'm very short in real life and everyone seems tall. I also have it in my head that he and Dorian are the same height -- yes, I realize this is contrary to my warning above -- so he can't be on the too-tall scale or higher.