I've never been pregnant....and never will. But would try to eat naturally and healthy as possible.
How much cycling would you do in 1 wk. in spring or summer on a normal basis? So with baby that will probably change...
Note: My sister didn't eat any of the above sports food even before pregnancies. She went jogging until she couldn't when baby got too big. She has run half marathon or 2.
She's a doctor and mother of 2 young children. Ages 3 & 6. She really had to watch her diet carefully because she was bordering gestational diabetes. (She managed to beat down diabetes 2 after losing 50 lbs. via diet and jogging regularily, before she became a mother.)
Note: Not all long distance/endurance cyclists even eat sports food. I don't and I've been cycling for the last 22 yrs. I've packed in 4,000- 7, 000 km. annually in some years. I go bike touring with my loaded panniers, etc. Meaning I have done hard taxing rides...and I still eat naturally, drink water, etc. It works for me. And this cycling 100 kms. daily consecutively for some trips.
Did I ever want to buy sports food? It NEVER occurred to me. But every one is different. I'll bet you my sister doesn't eat sports food because she and I grew up in Canada on the same diet...traditional Asian diet for first part of life, most of it not processed foods.
I guess my philosophy is: There's a huge part of world that doesn't know about sports food, but they work physically demanding jobs / undertaking demanding activities and they manage to live on their traditional diets. ('course I'm talking about countries with higher longevity in life...).