Ah Dr. Luke. I can't be too negative about her recommendations, because I think she does get good results (longer twin pregnancies) and has a good point about the importance of ample protein and good nutrition. But I can save you reading the book by saying:
Eat a lot. Especially protein. Lots of good stuff too, veggies, etc.
Also, I think she's got it somewhat wrong about activity. Sitting on the couch for 9 months is not good for many pregnant moms. Dr. Luke makes it sound like work and physical activity will put an expectant MOM into early labor. Not a doctor here, but I totally disagree.
STRESS is bad for expectant MOMs (even stress about how many grams of this and that you get daily). So if your job is stressful, or your commute, or you're on your feet all day and your body give clear signs that's not working, back off. I'd recommend if possible cutting out all non-essential activity as of 30 weeks. After 30 weeks I skipped traveling for Christmas, said no baby shower, etc. Because ultimately, those things were somewhat stressful to me. All I wanted was to go to my gentle office job and come home. That said, I was walking 2-3 miles a day and a brisk 5+ the day before my twins birth at 39 weeks. Walking made me feel good, and I was strong going into labor. But there were days where whatever activity or lack of water brought on bracton hicks, so I slowed down.
In summary - eat lots, cut out stress, and listen to your body. That's all.
I good book that recently came out is "Double Time" by Jane Roper, who has a great blog. I also liked "Twinspiration." Essential reading though would be this blog post and all the comments. It's old, but was so confidence building for me!