When some new members of my staff asked me to explain how Cook'n goes about analyzing the nutritional value of a recipe, it occurred to me that other Cook'n users might have similar questions. So here goes...
         When Cook'n analyzes the nutritional value of a recipe, it goes one by one through each ingredient, tallying up the values for each food. Even though an ingredient like butter, for example, has 26 different brands associated with it, Cook'n looks at the nutritional value associated with the "Preferred Brand."
         Since the nutritional information for each brand comes directly from the package label the analysis is VERY accurate.
         In fact, when we were developing the Cook'n for Diabetics software, we double-checked the nutritional analysis of each recipe. As you can imagine, with a product like this, the analysis had to be exact. There was no room for errors. The analysis for most of the recipes was similar to that presented in the paper back cookbook that the recipes came from. However, some of the results were way off.
         We went through the code with a fine tooth comb looking for some sort of glitch in the program but we couldn't find any sign of a problem. Finally, we called the author of the cookbook. She told us that the reason the results were different was because our analysis was more accurate. When a nutritionist analyzes the nutritional value of a recipe, she uses average nutritional values for each ingredient.
         The question many people have is why some ingredients don't compute. You may have noticed the "Accuracy" reading sometimes states a number less than 100%. When you scroll the shopping list to the right, you will see asterisks next to some ingredients. This is why:
         If a recipe calls for 1 can of tomato paste, Cook'n cannot analyze the nutritional value of this ingredient because it does not know what size can the recipe is calling for. Specifying the can size will fix this problem.
         Sometimes Cook'n needs help converting from a unit of volume to a unit of weight or from no unit to a unit of weight. For example, a recipe may call for 1/2 cup carrots. Since the nutritional information for carrots is defined for 3 ounces, Cook'n has no way of knowing how many calories are in 1/2 cup. 1/2 cup of honey weighs much more than 1/2 cup of flour. We must tell Cook'n the density of carrots, or how much 1/2 cup of carrots weighs.
         To tell you the truth, I don't know how much carrots weigh and getting out my kitchen scale is too much of a hassle. However, I do know that carrots and potatoes have about the same density...they weigh about the same that is.
         So, I looked up potatoes in Cook'n and discovered that 1 cup equals 148 grams. Since Cook'n just needs any volume to weight measurement to establish the density, this will work just fine. When we establish an Equivalent statement with "1" in the volume quantity field, "cup" in the volume unit field, "148" in the weight quantity field, and "grams" in the weight unit field, Cook'n can figure out the rest.
         If you're not sure what the density of a certain food is, an easy solution is to think of another food that is similar in density and look up that food's conversion values in Cook'n.
         I don't usually spend a lot of time analyzing the nutritional values of the food I eat. Rather, I focus on eating balanced meals. The challenge for me is getting enough fruits and vegetables...especially on the candybar diet that the other programmers and I are forced to eat when we have a deadline. :) However, I know that many people need to know how many calories, sugars, etc. are in the food they eat. I hope Cook'n helps!!
         Please let me know if you have any questions.

-Dan @ DVO