Have you always been at 137 pounds? To be honest you sound like you're on the skinnier side, and have the luxury of pigging out to put on muscle.

If you want to put on lean muscle then I recommend eating lean protein, healthy fats, and low glycemic carbs (mainly veggies and some fruits). You'll probably have to mess around with the ratios to see what works best for you. Good luck on your journey to 145.