I'm currently in the process of adding lean muscle mass and wanted to share what my typical day's diet is right now. It's worked for me as I've added close to 15 lbs of muscle in 15 weeks. The schedule below is around 3,200 calories and can be adapted a variety of ways whether you're looking to lose weight or add mass. You can take a look at how I space food throughout the day and adapt it to your own diet.
Typical Daily Diet
4:15 a.m. - pre-workout whole wheat bagel
During workout - P90x results and recovery formula drink
Immediate post workout - Aftermax recovery drink
6 a.m. - 6 egg whites, 2 slices turkey bacon, 2 low-fat waffles, 1 cup green tea
8 a.m. - protein shake
10 a.m. - banana
11 a.m. - serving of baby carrots
12 p.m. - 1 can of tuna, serving of fat-free cottage cheese
1 p.m. - shakeology with the following blended in -banana, natural peanut butter, 8 oz skim milk, handful of spinach, 1 scoop of protein powder
3 p.m. - apple or orange
4 p.m. - protein shake
5 p.m. - clif builder bar
7 p.m. - chicken with vegetables
Right before bed - serving of fat-free cottage cheese (casein protein is slow releasing and helps repair muscle tissue as you sleep)
Diet Summary
I also aim to drink 8 - 10 bottles of water per day. Hope this helps as I wanted to show it as much for spacing food throughout the day as anything. Good luck and let me know what I can do to help you and your goals in regards to your diet!