All you have to do is type in the serving size and the number of servings the recipe makes, when you create the recipe. Then, when you enter the food in your Daily entry, you can adjust the amount you ate.
For instance, if you consider 1/2 cup of your recipe to be your usual serving size, and the recipe makes 6 servings, when you enter it in your Daily Entry, it will show up as though you had eaten 1/2 cup. If, however, you ate 2 servings, just adjust that on your Daily Entry page. The program does the math for you and will automatically adjust the carbs, protein, fat and calories as needed.
Diet sodas are listed under carbonated beverage. The brand I drink may not be the same as the one you drink, so just select the one from the list that matches the ingredients of your brand. If you can't find one that seems right to you, just enter yours as a Custom Food. If you can't find the food you want at My P.L.A.N., you can usually find it on the USDA website. (Here's a link to their
Search page.) For flax meal, just enter the word flax in the search box. You will find a list there that includes ground flax. Then, just use the nutrient information to enter the ground flax as a Custom Food at My P.L.A.N.
Although it can take a bit of time to get your personal My P.L.A.N. food lists set up the way you want them, once you do, you'll find it very fast and convenient to use.