Most of the time, on nutrition labels, the macros (protein, fat, carbs) are rounded to whole numbers and the calories are rounded to the nearest multiple of 5.
Haven’t you ever noticed that? Very rarely will you ever see the calories as something like 148 calories per serving…they’ll round to a nice neat number. Or how we assume every egg is 70 calories? Because every chicken produces nutritionally identical eggs for our dietary convenience. Yeaaaah…no.
1g of fat has 9 calories. 1g of carbs has 4 calories. 1g of protein has 4 calories. So knowing that lets do a little label-review. I’m sitting here looking at a jar of Skippy Natural Creamy PB.
On the label, it says it has:
Cals from fat-140
Well, knowing what we know about how many calories are in these macros lets do some math.
16g fat x 9 cals/gram =144 calories from fat (so already, the label wasn’t completely accurate b/c it told us 140 from fat, but let’s continue)
6g carbs x 4 cals/gram = 24 cals from carbs
7g protein x 4cals/gram = 28 cals
So 144+24+28= 196 calories per serving, instead of the 190 cals listed on the label.
AND furthermore, remember, THAT is based on the rounded values of the listed macros. So, even 196 isn’t necessarily precise.
Basically, the point I’m trying to make is that if you’re focusing on calories understand that you’re never going to accurately be able to figure to the dot how many calories you ate in a day, so beating yourself up over an extra 50-100 you’ve tracked in MFP is pointless.