Calories Don't Add Up
In viewing the food log and the food graph, I note that the total calories value is not correctly calculated in the foods entry area, while it is correctly calculated in the Calories chart next to the pie graph. I've attached a screen capture to illustrate.
Note that the macro breakdown in this instance is as follows: protein 141.9, carbs 140.8, and fats 67.2. Rounding to the nearest whole number and applying the standard multipliers of 4, 4, and 9 yields a total calorie count of 1735. The total in the Cals, column, however, is 1674. The sum of all numbers in the Cals column does equal 1674; however, this is not correct.
Note as well the calorie breakdown pie chart and the component numbers given there. They are 567 calories from protein, 563 from carbohydrate, and 605 from fat. The total of these three numbers is 1,735, which is correct per application of the standard multipliers to the grams indicated in the food log.
It would appear there are significant errors in the way the numbers in the Cals column are obtained, and those errors are accumulating in the total calorie count at the bottom. It does not appear that the numbers in the Cals column are derived from the calculations on the macronutrient values, but it does appear that the calorie breakdown numbers are. The calculation method for the Cals column should be addressed and fixed, as it is the only way the number in the Cals column will be consistent with the calorie breakdown and, more importantly, correct.
Thank you for your consideration.
Great observation. I can't understand the difference between the macro calorie breakdown (and total) and the calorie column totals either; it doesn't make sense.
I'm wondering if it is linked to the how the numbers for the macro calories are pulled/standardized from food database items (listed in the calories column) prior to the macro calculations.
I'm guessing it stems from rounding off numbers going from ounces to grams or grams to ounces, as the numbers are pulled from the calories column to determine the macro calculations.
It only makes sense that only ounces OR grams would be used in the calculation for the macro calories, because there are different units (grams and ounces) being used in the calories column; so the units would have to be standardized first prior to determining the macro calorie breakdown.
If I am correct, this would make the Calorie Column numbers accurate and the Macronutrient Calories incorrect (and therefore the pie chart is not accurate). Therefore my hypothesis is directly opposite yours, however I agree that it looks pretty certain that a problem exists.
And something important to consider is this:
Even though your post is for Classic, if there is indeed a problem this issue may have found it's way into FD 2.0.
Using 4, 4, and 9 to calculate calories is a great rule of thumb but is not nearly accurate enough. (Some nutritionists recommend 4, 4, and 8 - which, in your example, would yield a number much closer to FitDay: 1668.) Either way, I would not trust a calculation that relies on 1 significant figure.
That being said, FitDay does not calculate calories at all. Each value in a food's nutrition information is stored separately in the database. No nutritional value is determined from a calculation that involves other nutritional values (excluding "Calories from Fat"). If you log a food that comes from our database, that information comes directly from the USDA. Custom foods are entered manually and FitDay does not alter those values.
FitDay only adjusts RDA and DV calculations which are determined based on the users age and gender.
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