Eat regularly. Rather than having two or three large meals during the day—something we've grown up with—change your eating habits so that you are eating five or six smaller meals during the day.
To help keep your protein intake high, one or two of those meals can be a protein shake. Here's one example, though a quick Internet search will uncover hundreds of delicious protein shakes:
8oz skimmed milk
1 banana
1 tbsp peanut butter
2 scoops of protein powder