In order to add an ingredient that is missing in the food list, do the following steps:
1. Tap on the "+"-icon and go to "Add Ingredients"
2. The food list opens
3. Now type in the desired food in the search, e.g. whole wheat bread
4. Select whole wheat bread in the search results and it will appear as an ingredient in your meal
5. Tap "Save" in the upper-right corner, then tap "Save All".
From now on, whole wheat bread will appear on your food list.