How to Read Carbohydrates on Nutrition Labels

How to Read Carbohydrates on Nutrition Labels

When you are on a mission to nail your nutrition and improve your physique its pretty important to know whats going into your gob.


But if you don't know how to read nutrition labels trying to figure out what foods are going to take you towards your goals and which ones are not can be a tough job.


I've found the one thing that people have the most trouble with when it comes to nutrition labels is working out the what's going on with the carbohydrates section.


You've got the total carbohydrates

Then under that sugars

and under that fibre.

How much is too much carbs? Does it matter if there is low sugar? What about if some of the carbs are fibre? Do I look at quantity per serving or quantity per 100g?


I'm going to clear it up for you once and for all. Explain what it all means and what to look for.


Serving Size or Per 100g

First off serving size. The serving size is just the amount the manufacturer considers to be an average serving. Unless the food comes in individual serves you have no way of knowing how much you are getting.


For example this muesli says the serving size is 45g which is not much at all. An average size bowl full could easily be over 100g. Also serving size doesn't give you any context into the percentage of carbs in the food.


This is why I always say look at how much per 100g. Then you can know exactly what you're having and can also tell the percentage of carbohydrates and sugar in the food (as well as protein and fat). This way no matter the amount you have you can work out how many grams of carbs you are consuming.


Carbohydrates on Nutrition Labels


Breakdown of the Label

If we break down the carbohydrates section of a nutrition label it usually has 3 parts.



-Dietary fibre


The top carbohydrates row is the total amount of carbs present. Made up of all the sugars, dietary fibre and starch, which is the remaining amount after the sugar and fibre.


So in the above muesli label we have 51.8g of carbs per 100g.

12.7g is sugar

7.9g is fibre

Which means that 31.2g is starch (51.8 - 12.7 - 7.9)


Trying to determine how much total carbs is too much depends totally on the amount of the food you are having, your nutrition requirements and needs.


If you are going low carb then some jasmine rice with 40g of carbs per 100g (cooked) is not going to be on the menu. However if you are having a moderate amount of carbs in your diet then some jasmine rice is a great choice.



The sugars are the main thing you want to keep low. Sugars can be naturally present or added. They can come from sucrose (table sugar) fructose, lactose, glucose and many other sources. Be careful of supposedly healthier natural sweeteners such as coconut sugar, agave, honey, dates etc. When it comes down to it they are just more glucose and fructose.


Also just because a food has low sugar does not mean its a free ride. If you are trying to manage your blood glucose levels foods high in processed starch such as breads and cereals will still jack your blood glucose levels higher than you want them.



Fibre is much harder to digest than starch and sugars and it doesn't increase blood sugar. It also provides a feeling of fullness, lowers the GI of the meal and is good for digestion. So when looking at the amount of carbs in a food you can subtract the fibre from the total. This gives you the usable carbs or net carbs.


As for calories in fibre - Insoluble fibre doesn't contain any calories and cannot be broken down. While soluble fibre can be broken down by bacteria in our colon to produce fatty acids which do provide energy.


To keep it simple though I just advise people not to worry about fibre and not to count it towards their total carbs.


This means if a food seems like it has a reasonable amount carbs but has a lot of fibre after you take that into account it can lower it substantially.

Carbohydrates on Nutrition Labels


As you can see with this Quest Bar nutrition label it has 25g total carbs, 16g fibre, 1g sugar and 6g erythritol (explained below). So the total net carbs is only 3g. Which is very different from the total of 25g.


Sugar alcohols.

Sugar alcohols are often found in low carb or sugar free foods as they give similar texture and sweetness of sugar but are not considered sugar on the label. They will be labelled separately under carbohydrates though which is what the the erythritol is in the quest bar above.


There are quite a few different sugar alcohols used in foods each with different characteristics. This chart compares the sweetness, glycemic index and the calories per gram of different sugar alcohols compared to sugar at the top.

Ingredient Sweetness GI Cal/g
Sucrose(sugar) 100% 60 4
Maltitol Syrup 75% 52 3
Hydrogenated Starch Hydrolysate 33% 39 2.8
Maltitol 75% 36 2.7
Xylitol 100% 13 2.5
Isomalt 55% 9 2.1
Sorbitol 60% 9 2.5
Lactitol 35% 6 2
Mannitol 60% 0 1.5
Erythritol 70% 0 0.2


As you can see the ones at the top like maltitol are not that different from sugar. While Erythritol comes out the clear winner with next to no calories and 70% sweetness.


As for including sugar alcohols in your diet. I always suggest limiting processed foods and sticking to whole foods as much as possible in which case you won't be consuming any sugar alcohols. But having small amounts of them in the odd quest bar or something isn't a big deal.


Just know that if your having a protein bar with a bunch of maltitol, it is not a free ride for calories and GI.


Hopefully now you have a better understanding of how to read the carbohydrates section of nutrition labels. Being able to interpret them will allow you to make better choices for your goals rather than trusting the marketing on the front of the packet which can often lead you astray.

Leave a comment!

You must be logged in to post a comment.