Congrats on the weight loss! That's hard to do at our age! I'm 5'6" and 46, and would love to weigh 132!! How did you do it? Just with lower calories? I'm in a similar starting range and would love suggestions.

That said, to build muscle you'll need to up your calories. You'll probably want to do it slowly. Look up reverse dieting. Bumping it back up to your TDEE will allow you to build muscle without Gaining too much weight.the recommendations are always 0.8-1 g of protein per lb of lean mass, but I've also seen recommendations for per lb of body weight. I shoot for the 120g mark a day.

Are you lifting weights? It's been amazing for me! Hope to get to know you more on here .

Best resources for this type information can be found in this group's stickie
http://community.myfitnesspal.com/en/discussion/833026/important-posts-to-read/p1

This is really useful info folks, I'm 52 and have reduced my weight from 77kg in January to 68.5kg right now (I think that's about 18 pounds loss) - I worked with a personal trainer who encouraged me to eat more protein but in balance with other macros, I've tried to stick with 40% carbs, 30% protein and 30% good fats. It's been quite hard to increase my protein and I now use whey protein every day in a smoothie. I probably need to do more weight training now to improve muscle tone a bit more noticeably, but I'm scared stiff to increase my calorie intake after losing this weight over the last seven months

Go to the iifym site as recommended on the earlier post. Will give you a good idea. Studies show you can be as low as .8 up to 1 gram per pound but most will say 1gram per pound of LEAN body mass or slightly more for building. But each person is different.