If you are tracking macronutrients, do you trust and use the package information or do you calculate your own and use that?

Here is a case in point...
The IP BBQ Chips label reads as follows:
1 Bag = 120 calories
15g Protein
4.5 g Fat
12 g Total Carbohydrates

However, if I calculate out the calories, it goes like this = 4*(15+12)+9*4.5 = 148.5 calories.

I don't want to obsess about this as we are talking about 30 calories but this adds up throughout the day and I am curious as to what you do. I have always taken the higher count but then I was thinking, "How could IP get their own nutritional label wrong"?

It is interesting...I just found an article on this issue and they said that to be more accurate, use a compensated 4-4-9 method or they call unrounding process.

For my example, that would mean the following:
148.5/120 = .81
15 g * .81 = 12.12 g * 4 = 48.48
12 g * .81 = 9.70 g * 4 = 38.80
4.5 g * .81 = 3.65 g * 9 = 32.85
Now when I total that up, I get 120. And, if I calculate the % of calories from, it now adds up to 1005 whereas with the packaged nutrition it did not, which is why I switched to using the 4-4-9 method and ignoring the packet calculations.

I now wonder if I should count this as have 12 g of protein or 15 and 12 g of carbs or 10???

I am probably obsessing but with so few calories and such, this adds up throughout the day.

As in my case, this equates to 100 calories in the day. Per package information, it states that I am consuming 100 calories less than what I am counting by following 4-4-9 method. I think I am cheating myself. This is especially important, because when I had IP minimums, calculating the package calories, it noted that I only ate 650 calories rather than 750. It seems like I should use the package amounts and adjust them by ratio to get the % of calories from protein, fat and carbs to sum to 100% without cheating myself.

You have found the devil and he is right there in the details .

If your Saturday is as lively as mine, you might appreciate this interesting bit of reading from the FDA. And here's an article from Market Watch --6 paragraphs down. Basically, the serving size is allowed to be 20% more than the amount that appears on the label. Guess you found that unreported 20%!

Does it not make you angry to realize that this company, whose mission is to assist with weight loss, chooses to under-report calories? Just because they can?

Although it is strange that the protein and carb amounts do not match the calories.