The placenta is what makes a woman diabetic during the pregnancy. It really strains the body and forces your own body to keep sugar in your system longer in order to make it accessible to your fetus. So it's good to keep track of your sugar when you are pregnant even if you are not diabetic. I remained diabetic after my pregnancy (and no, I did not have it prior to pregnancy, but I did have PCOS which made GD that resolved to diabetes a very high likelihood.) My baby was born at 38 weeks and was 6 lbs 13.4 oz, 18.5 inches long. Her father is Chinese, so she was normal sized for a baby in his family and she was small for my family.
FYI, everyone in my "Sweet Expectations" pregnancy group reported feeling tired and cranky after eating sugar, although we were told by the nutritionist that this was weird. You should only feel really "sick" when your blood sugar gets too low. However, the two times my blood sugar got really low, I only felt sick once. I always felt more tired and crabby after eating too many carbs. Counting carbs is the way to go during pregnancy. If it's too little, you can always eat more, but what I'm about to outline is for GD.
I still eat this way most of the time:
My meal plan from my GD pregnancy
Breakfast 30g of carb (this was roughly 1 piece of high fiber toast with butter or cream cheese)and a small apple. I also usually ate a poached egg. If I had oatmeal, that was all my carbs for the breakfast, because I would put some nonfat milk in it. Milk has carbs. One serving of carbohydrate is usually 15g of carb.
snacks 2 hours after eating: turkey & cheese roll ups with fruit= 15g of carb or a half sandwich or half a whole wheat pita with cream cheese dip.
Lunch: 30g of carb. This was about 1 tablespoon of Hummus and carrots or 1/3 cup of beans and 1/3 cup of rice. I'd also eat steak or chicken and have a salad.
I tried to make my snacks that weren't main meals my "treat" times. I realized that I could have haagen dazs chocolate chocolate chip every so often, so that satisfied my chocolate urge (and taught me portion control for those little pints. One pint should last 8 servings at 15g snacks. It also had chocolate, fats and protein.) Sometimes I'd just have yogurt or a bowl of cherries.
I also found out which fast food items I could eat: mcd's double cheeseburger has only 30g of carbs, and 2 corn tortilla tacos from taco bell have exactly 30g of carb.
Dinner was similar to lunch, but you could have 45g of carb. So I could have more rice or beans or actually go out. However, if went to greek or mexican food, I skipped the rice altogether and asked for a box and put half the hummus or beans in right away and concentrated on eating mostly the protein and veggies.
If you're on insulin when you are prego, they make you eat a late night snack. It's good even if you're not because your liver kicks out more sugar when you are sleeping and GD women are always highest in the A.M. because the body interprets that stuff as "fasting". So eating a protein/sugar/fiber/fat snack before you actually brush your teeth and hit the bed is good for all pregnant women, as it keeps your blood sugar more stable. High fiber crackers and cheese is good; glass of milk and an oatmeal cookie is good; green salad with jicama and chopped chicken with a yogurt dressing is good; carrots and hummus or turkey cheese rollups are good as well.
I also liked eating natural peanut butter on apples, mayo with, artichokes and the weight watchers zero point soup with buttered high fiber toast.
The best way to eat a food that has carbohydrate is to mix it with fat and fiber or protein, it slows the blood sugar. All low glycemic index meals are combinations.
Anyway, portion control is always good, and keeping your sugar down is smart no matter how "normal" your pregnancy is.
good luck, congrats, and take care!!