"If you don't like what you see in the mirror, what difference does it make what the scale says?" – Vince Gironda
Men and women alike obsess over the number staring back at them from the scale. What they need to be focused on is true body composition. The mirror is the ultimate judge, not your weight.
For many guys who want to look bigger, get lean first – the ideal is around 10% body fat. This alone will have you looking your best and it will make building pure muscle exponentially more effective.
If you're a naturally skinny-limbed dude, consider your expectations. Can you expect to develop the body of an NFL running back? More often than not, the average 5'7 to 6'0" guy looks much better at 165-185 pounds and 8-12% body fat than at 200-plus pounds at 15% body fat or higher.
If your goal is fat loss, take girth measurements around your waist, chest, arms, and thighs every two weeks as well as progress photos in your skimpies. The scale rarely cooperates. Many folks end up building lean muscle and losing fat concurrently. They see the scale hasn't changed much and proceed to throw in the towel. Stupid scale.
Use other tools of measurement, especially the mirror. It may be humbling at first, but you'll be astonished at how little scale weight means when you transform your body.