You may be better off to stay with all natural snacks and meals (these can be time consuming to make, so preparing and planning in advance really helps) like nuts and low gi fruits and crockpot stew.
Yes, grains are handy, quick and easy, but they contribute to arthritis, pre-mature ageing and in your situation a health risk to not only yourself, but the child you carry. Grains are easy to produce and easy to sell, but this is in no way linked to good health. For example, corn is in everything pre-packaged, it is also used to fatten up livestock such as cattle; so it can only be assumed that corn is linked to weight gain and the growing epidemic of obesity. Another example is Monosodium Glutamate (MSG for short) that is added to these products to make it taste good; although a product may be labelled with "NO MSG" on the surface, this only applies if you eat as little as 1/10th of the package. Companies will deliberately use other terms such as "flavouring", "yeast extract", "hydrolysed wheat", and many more (there are over one hundred different terms companies will use to cover up that they used MSG in the product to make it taste good,) regardless of the fact that this product is harmful to your health, especially to your heart.
I know where you are coming from with your diseases, as I too have a gastric disorder, and I can also see the importance you need healthy snacks with your pregnancy.