Macro v. Total Calories Math Question

mattemery

I'm confused. My Macro Targets don't add up to my total calories. Example below from yesterday.

Totals 1,645 206 39 151 40
Your Daily Goal 1,700 191 38 149 25
Remaining 55 -15 -1 -2 -15
Calories Carbs Fat Protein Fiber

As I understand it, Calories = (9 * Fat Grams) + (4 * Carb Grams) + (4 * Protein Grams).

Fiber doesn't count toward calories.

This works with my "Daily Goal", but never with my Daily Actuals. Sometimes it is fairly far off, sometimes not so much. Above, the math says 1,779 calories, but the website calculates 1,645. That is 134 off, or 8%. That seems pretty big to me. rounding can't be the reason.

So help me. What am, I doing wrong?

Sublog

Fiber does provide calories.

It's usually closer to 2 kcals/g instead of 4. Also, some other CHO's are < 4kcals (Sugar alcohols for example).

Also, the MFP db rounds up, which will skew math + some entries are flat out wrong.

mattemery

Fiber does provide calories.

It's usually closer to 2 kcals/g instead of 4. Also, some other CHO's are < 4kcals (Sugar alcohols for example).

Also, the MFP db rounds up, which will skew math + some entries are flat out wrong.

Hmmm... That makes the error worse. If I include 2kcals for fiber, the math works to 1,859 instead of 1779, making it 214 Calories off (13%).

And, that makes the "Goal" calculation not work.

No sugar alcohols included in anything I eat.

So, I don't think that is it.

Sublog

You will be better off examining your foods at an individual level instead of as a daily level. Sometimes macros and calorie content do not match up on mfp db items. You need to double check all the food you enter to ensure it makes sense.

I've seen some stuff with wildly inaccurate macros.

mattemery

You will be better off examining your foods at an individual level instead of as a daily level. Sometimes macros and calorie content do not match up on mfp db items. You need to double check all the food you enter to ensure it makes sense.

I've seen some stuff with wildly inaccurate macros.

That's IT!!!!! Thanks. I pasted the daily diary in a spreadsheet and found almost ALL the errors were on 2 food items I was using. Looks like the user entered data is off sometimes. I'll correct that for the foods I use, and pay closer attention to what I pick.

MUCH appreciated. This was driving me nuts.

issyfit

You are absolutely right, mine added up to 4% more calories than it says for yesterday. even though the goals add up ok. I didn't count fiber separately because isn't it included in carbs?

mattemery

You are absolutely right, mine added up to 4% more calories than it says for yesterday. even though the goals add up ok. I didn't count fiber separately because isn't it included in carbs?

Looking closer.... there are 2 problems with the data I see.

1) As I said, some food items are just entered wrong.
2) Fiber is usually included in the total "Carbs" number. it has to be subtracted before you multiply the grams by 9.

Also, following up on the previous post. He is partly right. SOME fiber has a caloric value. See:
http://www.bodyrecomposition.com/nutrition/fiber-its-natures-broom.html

So... my conclusion on this whole issue:

1) pay attention to the food you enter and make sure the info on MFP matches the nutrition label. If there is no label (meat/produce), and the numbers don't look right... cross reference with something like LiveStrong or CalorieKing.
2) Don't worry too much about the macro nutrients adding to the total calories.
3) If the total calories match the label (or cross reference)... trust the calories and use the macros as a guide.

misty589

I think you might just be over-thinking it.
most values in a serving aren't going to be an exact number, so if you log something as 50 calories, it may really be 49.345 calories, and that 2 grams of fat may only be 1.584 etc that can make a big difference when you log, say 25 individual foods in a day. Plus, I know i don't check every food to make sure it's exactly right in the database, I just make sue it looks reasonable, there could be small errors there as well.

mattemery

I think you might just be over-thinking it.
most values in a serving aren't going to be an exact number, so if you log something as 50 calories, it may really be 49.345 calories, and that 2 grams of fat may only be 1.584 etc that can make a big difference when you log, say 25 individual foods in a day. Plus, I know i don't check every food to make sure it's exactly right in the database, I just make sue it looks reasonable, there could be small errors there as well.

With small things like that, I agree. But let em give you an example of a food I entered:

6oz Grilled Salmon... showed 165 calories, obviously no carbs (or therefore fiber), 43 grams of Protein and 8 grams of fat. That was what was in the database, so it went in my Diary.

(43*4) + (8*9) = 244 calories. Now THAT is a long way from 165. 47% more. It can't be roundings, etc...

The food in the DB is just WRONG. Now, from what I see on Calorieking.com, the Protein and Fat are about right, and the calories should be closer to 250. So, whoever entered this in the DB got the Macros RIGHT, but the Calories WRONG.

This is big enough to think about. In my opinion.