The second trimester, since I was lucky enough that my morning sickness ended, was mostly smooth sailing as everyone says. I felt fine, I wasn't showing (as long as I didn't wear belly-tight clothes), and I could do what I wanted (although I got winded easily). The challenge here was to fight the fuzziness of "pregnancy brain." Since I just finished an engineering Ph.D., people think my brain works. Well, pregnancy trumps a degree, and I had to work hard to keep my brain as sharp as possible. It was tough, but the payoff is that it "sticks" and I'm pretty functional brain-wise. Still, I have been a better multi-tasker. I used to take on 4 different tasks at work, not more like 2 at a time. My co-worker Chuck says the other two threads are talking to the baby even if I don't know it.
In the second trimester, I noticed that I felt a whole lot better with light daily exercise. I did stretches, light free weights (I've never seen 5 pounds free weights change my arms in two weeks, a pregnancy bonus! I usually lift a lot more too), and (if not too tired) elliptical trainer. I was slower and needed more sleep, but I pluged away at it, and exercise is a priority. I recommend it!
Least favorite foods: anything with much fat (no fried food) or salt. Fat/grease upsets my stomach, and salt makes my chest feel tight. On the other hand, my blood pressure is fine and everyone says I look healthy. Fat and salt aren't much of a loss, although it's difficult to eat out.
Favorite food: half a grapefruit for breakfast!
You can fight pregnancy brain fuzziness, and I think it's worth it in the long run as well as the short term. Exercise is good, and goes well with feeling better.
Total weight gain: up 5 pounds.