I get this question a lot from people who recently started to track their calories and macro-nutrients: Why don’t my macros equal my calories?
Carbs and protein contain 4 calories per gram, and fat contains 9. So if you consumed, for example, 20g of protein, 30g of carbs, and 10g of fat, you should have consumed 290 calories (Protein: 4 x 20 = 80, Carbs: 4 x 30 = 120, and Fat: 9 x 10 = 90).
But a lot of times, the math doesn’t end up right. It might say you consumed 250 or 300 calories, so what gives?
There’s several possible causes:
1) Everything in nutritional labels are rounded, therefore, it has a slight margin of error. On top of that, many websites (like MyFitnessPal), also round their own numbers. So by rounding it twice, when you add a lot of food and items, that error can become significant enough to be noticeable.
2) Sometimes insoluble fiber isn’t counted. Some products and some countries don’t list insoluble fiber in the total amount of calories because it’s not absorbed. So that will throw the carb/calorie math off.
3) The numbers on a specific food are wrong. This is quite common in websites like MyFitnessPal, where the database of the foods is created from the users themselves. This means that if the user introduced the nutritional information wrong, you’re using the wrong numbers.
So what should you do about it? For the most part: nothing. For the first 2 reasons, it won’t be relevant, and as long as you’re consistent in your diet, it won’t matter. However, you should be careful with number 3, because there’s no way to tell how off it really is.
To fix this, simply pay attention to the numbers being given after you introduce a food. If it seems off (for example, seeing that rice has more protein that you’d expect), double-check the macros and calories with the nutritional package, or if there isn’t one, check on nutritiondata.self.com. If it’s wrong, either search for another food entry that is correct, or just make your own entry, which takes about a minute, and you only have to do it once for each food.
If you really want to be as accurate as possible (if you’re in contest prep or making weight, for example), don’t use foods from the users database, and introduce everything yourself.
In the end, it’s not a big deal, just pay attention to make sure the entries you’re using are accurate, and don’t worry about the calories and macros matching perfectly.
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