Congrats on the twins! How exciting!
I am a big believer in the Barbara Luke book. I had 2 previous singleton pregnancies and had a different "goal" for those pregnancy- namely to eat healthily and in moderation. When I found out about my twins pregnancy, the Barbara Luke book changed the way I thought - suddenly moderation wasn't a goal AT ALL and I was forcing myself to drink water (even though I hated to have to pee all the time). I'm so glad I followed her advice (even though my OB told me to watch how much I was eating) because at birth my twins weighed a healthy 6lbs and 6.5lbs. I was so afraid they would be too small for the infant carseats we had or worse that they'd end up in the NICU. As it turns out, they never spent a minute in the NICU.
Try now to eat things with high calorie content. Do you like milkshakes? Malts? At least you are getting some calcium in there too. Trail mix usually has a lot of calories as well as dried fruit. Nuts are great for you, have a lot of protein and are usually high in calories.
I'd just try to keep munching on stuff like that all day long. And yes, you will get big, but just keep thinking "its for the babies." They really need those calories.
" I object to violence because when it appears to do good, the good is only temporary; the evil it does is permanent." Mahatma Gandhi
"This is the ultimate weakness of violence: It multiplies evil and violence in the universe. It doesn't solve any problems." Martin Luther King, Jr.