Decoding sugar on the label and in your diet everything you want to know about sugar

Sugar: everyone is aware it’s good to avoid it, but first we need to know how to spot it. Are sugars and carbohydrates the same? How to identify sugar on product labels? How do I know how many teaspoons of sugar a product contains? Are all sugars sweet? Here are the answers to any questions you may have about this food component.

Anna Urbańska

Defining sugar and sugars can be tough, as the proper nomenclature is often different from the colloquial names we hear in the media and use ourselves. It is also somewhat different from the nomenclature used in labelling legislation. Take your time and try to comprehend how it works.

Carbohydrates = sugars = saccharides – proper chemical names of sugars

Let’s start with a very broad term: the name ‘carbohydrates’. In chemical terms, carbohydrates are organic molecules composed of carbon, oxygen and hydrogen. More specifically, they are aldehydes or ketones bonded with hydroxyl groups. Various carbohydrates differ in terms of:

  • properties,
  • digestibility,
  • impact on blood sugar levels.

Carbohydrates can also be referred to as sugars or saccharides, all these names are correct. Carbohydrates include:

  • Simple carbohydrates (monosaccharides);
  • Complex carbohydrates (complex sugars, polysaccharides), which include:
    • Disaccharides, double sugars (composed of two sugar units),
    • Oligosaccharides (consisting of 3 to 10 sugar units).

For instance, potato or buckwheat starch is a complex carbohydrate; sucrose (white sugar in the sugar bowl) and lactose (milk sugar) are disaccharides; maltodextrin is an oligosaccharide; while glucose and fructose are examples of simple sugars.

A completely separate group, that is not chemically classified as sugars, are the polyols you probably know as healthier sweeteners: xylitol, maltitol, sorbitol, erythrol and most sweeteners ending with -ol.

Carbohydrates can be also classified as digestible carbohydrates (that can be digested by humans and transformed into energy) and indigestible carbohydrates, or dietary fibre.

You have gone through the strictly scientific part of your reading. Now you know that ‘sugars’ can mean buckwheat starch, lactose from milk, totally indigestible dietary fibre, or fructose from fruits, to name just some. Sugars (carbohydrates, saccharides) are a very broad group of molecules. You may be well aware now that they will affect our bodies in different ways and some of them will even be indigestible by humans. There are healthier kinds of carbohydrates, which should be eaten in larger quantities (such as dietary fibre, starch) and sugars which should not be consumed in excess (such as sucrose).

Names of sugars and carbohydrates in dietetics vs. food industry

You instinctively know for sure that if you hear someone say they are ‘cutting down on sugar’, they do not mean cutting down on the entire group of carbohydrates altogether. That’s because the nomenclature used in the food industry is somewhat simplified. It differs from the chemical names. According to European Union legislation, the two most important definitions are:

  • Carbohydrates – any carbohydrates which are metabolised by humans, including polyols.
  • Sugars – all monosaccharides and disaccharides present in food, but excluding polyols.

If the nutrition label of a product states ‘of which sugars’, you can expect it to mean the presence of simple sugars, such as glucose and fructose, but also double sugars: sucrose, lactose, maltose etc. The term ‘sugars’, however, excludes polyols such as xylitol, sorbitol, or maltitol, as well as dietary fibre and complex carbohydrates.

FAO experts make things a little bit more difficult by using the term ‘simple sugars’ when referring to all monosaccharides and disaccharides in food. Sucrose and lactose, although in chemical terms they are not simple sugars but disaccharides, are therefore colloquially included in this group.

Total carbohydrates’ on the label refers to all types of carbohydrates available in the product, whether digestible or not. To calculate their amount in a food item, we simply deduct the content of all other ingredients (proteins, fats, water, alcohol). They are called ‘carbohydrates by difference’.

The term ‘digestible carbohydrates’ covers all carbohydrates metabolised by the human body, as well as polyols. But the indigestible dietary fibre is excluded. The term ‘digestible carbohydrates’ is not always present on the packaging. Oftentimes, if you want to check their content, you need to deduct dietary fibre from ‘total carbohydrates’ on your own.

That’s not all yet, we should also define the term ‘added sugars’, or ‘free sugars’. These are carbohydrates delivered by ingredients added in the production and preparation process to the final product. The term free sugars also includes sugar from natural ingredients, such as honey, syrups, fruit juices or fruit preserves.

While some simple sugars have the same chemical structure, depending on where they come from, they will have to be classified in other groups. For instance, fructose which is naturally present in apples is classified as a simple sugar, but not as added or free sugar. The same fructose, when it comes from honey, will be considered as an added and free sugar.