Exchange Estimator ©2003 Kathy Porter, Judy Mento The actual calculator is on the sheet entitled Calculator. There are TWO ways of using this calculator. One is for individual foods … like a can of soup. The other way is for a recipe containing several ingredients like a chicken casserole. Note: use the calculator tab for your estimations; that way you will leave the samples as they are. This way you can refer back to the samples if you need to (especially handy at the beginning; eventually this will become "second nature" to you, but in the beginning, having the samples to refer to might be helpful). SAMPLE #1 - Individual Foods: I'll give you a sample of the first way on tab entitled Sample #1. Note, insert the nutritional values (calories, fat grams, protein grams & carb grams) in row 5. For individual foods, be sure to enter the # Servings in Recipe in row 14, column K as 1. Then estimate the exchanges by inserting your estimates in rows # 17-24 in column D. As you insert your estimated exchanges, the nutritional values (calories, etc.) will appear in the corresponding rows in columns E-H, with the amounts "left over" appearing on row 25. It will never come out exactly (well, rarely), but you should be able to estimate enough exchanges to have very, very small amounts left over. The fluctuation is not unexpected because of the variations in calories for foods in an exchange group. For example, beef might has as much as 60+ calories and still be counted as a lean meat exchange while fish might have as few as 25 calories and still be counted as a lean meat exchange. I prefer to err on the side of caution so I tend to overestimate (I'd rather have negative numbers for my "left over" exchange values). On the sample I used a chicken soft taco supreme. The nutritional values are 230 calories, 10 grams of fat, 15 grams of protein and 21 grams of carbohydrates. To account for the carbs, I estimated that it's got 1.4 breads (1 bread has 15 g carbs, so 21 g would be exactly 15 x 1.4). So that would account for all the carbs. Because a bread exchange also provides 3 g protein, let's do it next. With the 1.4 breads, we have accounted for 4.2 g of protein, leaving us with 10.8 g. left to account for. A Protein exchange has 7 g of protein so 1.5 seems a reasonable estimate -- 1.5 x 7 = 10.5. That leaves .3 g protein "left over", and IMHO, that's "close enough". Now let's do the fats. A Protein exchange will provide 3 g fat, so we've already acounted for 4.5 g fat (1.5 Proteins x 3 g Fat/Protein). That leaves us with 5.5 to account for. A fat exchange contains 5 g fat, so 1.0 seems like a reasonable estimate, leaving us with .5 g fat "left over", again "close enough". Now let's double check to make sure we've got everything accounted for (yes, I'm an accountant!). Breads provide 80 calories, Fats 40 calories and Proteins 60 calories, so 1.4 breads will provide 112 calories, 1 fat will provide 40 calories and 1.5 meats will provide 90.0 calories. The spread- sheet adds them up and comes up with 242.0 calories. Close enough. I'm comfortable with the estimates and will use it. Play around with it, especially with foods that you already know the exchanges for so you can get a feel for it. If you need additional information or assistance, please be sure to let me know. For individual foods, you'll just enter nutritional values in row 5 and estimate exchanges in rows 17-24. SAMPLE #2 - Recipes I'll give you a sample of the second way (recipe with several ingredients) on the tab entitled Sample #2. The concept is going to be very, very similar to the first sample, except we're going to have several ingredients (for the ENTIRE amount of the ingredient, not just one serving!) and try to come up with exchanges for the "finished product". Insert the nutritional values (for all the ingredients) just like you did with the first sample. Do NOT estimate exchanges for those ingredients. We will instead estimate with the totals to avoid having to round up several items and coming up with a less accurate estimate (it's ALL estimated but I try to get as close as I can), as well as saving the effort and time of having to estimate for every single ingredient. When you are all done entering the nutritional values for all (you can skip adding ingredients that don't add any nutritional values such as water, salt, baking powder, spices, herbs, etc.), then enter the number of servings in Cell K 14. The in Row 16, you'll see the nurtritional values for individual servings. Now you estimate the exchanges just as you did in Sample #1. I've inserted the nutritional values for ingredients to make a chicken/rice crockpot casserole in the appropriate places in Sample #2. I used the very same logic in estimating the exchanges as I did in Sample #1, and in this case, while I got really close to zeros on the fats, carbs & proteins, I have a pretty large negative number on the calories. I could have gotten the calories closer to being zero'd out, but thought it was more important to get closer on the exchanges; I prefer to estimate on the conservative side myself (figuring that it will all even out eventually since my estimates are just that -- estimates. Again, after you've played with it for a while, you'll figure out how accurate (i.e., decimal places) you want to be, etc. The important thing in these two samples is to see how the calculator works. It's not an exact science -- we're estimating after all, and contrary to my preference for pinpoint accuracy, close is really very good. I hope I haven't made this too difficult or the instructions so wordy that I lost you after the first 5 lines! If you have ANY questions, please don't hesitate to ask. -- Kathy Porter