Even though I am currently pregnant, I still keep a food diary. When I'm trying to lose weight, cut fat or build muscle mass, a food diary helps me track my diet to ensure that I'm getting the proper nutrition for my goals. I figured it could do the same for me during pregnancy.
But keeping my food diary, I help ensure that both me and the baby are getting plenty of nutrients. I can quickly glance at a week's worth of entries to find out if I'm short on veggies, fruit or whole grains. I can also find out if I've been having too many treats of ice cream and brownies.
I've been keeping this food diary for years. Simplicity is one of the reasons I've been able to maintain it. I don't track macronutrients, and in some cases I don't even track portion sizes. A typical entry might look like this:
10:00 AM: 3 scrambled egg whites, 1 slice whole wheat toast, 1/2 apple
Although it's not incredibly detailed, it's just enough info to help me stay on track.