The nutrition label: where carbohydrate is listed

You find it in the nutrition declaration table, on the line called "Carbohydrate". In the European Union the table has seven mandatory lines, always set out in the same order:

• energy;
• fat;
• of which saturates;
• carbohydrate;
• of which sugars;
• protein;
• salt [1].

The "of which sugars" line is part of carbohydrate, so the number you need is still a single one [2]. Optional lines may appear below it, such as polyols or starch. Do not confuse the table with the list of ingredients. On some products the table also has a second column, with the values for one portion.

The word brings together the carbohydrate that the body uses: starch, sugars and polyols. This is the number you count, and nothing else on the label is added to it. The European rule leaves fiber out of it, on a separate line, because it is not digestible. That is why the carbohydrate value is the number you start from to work out your insulin dose [1].

Polyols, namely sorbitol, maltitol, xylitol and erythritol, are counted in the carbohydrate value as well, even though they raise blood glucose less than sugar does. They also provide fewer calories [3]. In confectionery sweetened with polyols the number on the label can be larger than the real effect. If polyols exceed 5 g per portion, you subtract half of them, and erythritol in full [4]. Any change to the dose is discussed with your doctor.

It is the part of carbohydrate made up of simple sugars: glucose, fructose, sucrose, lactose, galactose and maltose. The label puts the naturally occurring ones together with the added ones, without separating them. Being a subdivision, the "of which sugars" value is already included in the "Carbohydrate" line, so you never add it on top. If you add them together, you count the sugars twice and the insulin dose comes out too high.

A high proportion of sugars usually signals a faster rise. The rule is not reliable, though: fructose and lactose raise blood glucose slowly, while the starch in bread raises it quickly [5]. If you want to know which sugar was added, read the list of ingredients, where sugar, glucose syrup or honey appear.

In the European Union the mandatory basis is always 100 g of product for solid foods and 100 ml for liquids. That is exactly why you can compare two products directly, without any calculation. The per-portion column is optional. The manufacturer may add it on the right, but may not put it in place of the values per 100 g of product. The order and the units are the same on every product [6].

The most important trap is the portion. The declared portion is chosen by the manufacturer and is often smaller than the one you eat, for example with breakfast cereals [7]. Check as well whether the values are given for the product as sold or after cooking. Pasta, rice and instant soups are usually declared raw, before cooking. For a can, weigh what is left once the liquid has been drained and check what the values refer to.

You weigh the portion, then multiply the grams you get by the value on the label and divide by 100. If the cookies have 70 g of carbohydrate per 100 g of product and you eat 40 g, the calculation gives 28 g of carbohydrate. A quick trick is to divide the value on the label by ten and find out how many grams of carbohydrate there are in 10 g of food. For liquids you use milliliters, in the same way [2].

To count correctly, you have to weigh the food raw or ready cooked, as the label says. If you are not careful, the result can change a great deal. Do not agonize over the decimals, because being one gram out does not matter. Even so, a portion judged by eye can sometimes be quite far off, as the figure below shows [8].

No, not on a European label. The "Carbohydrate" heading covers only the carbohydrate that the body metabolizes. Fiber is not digested in the gut, so it stays outside that heading. It may appear on a separate, optional line, which is missing from many products [9]. So you do not subtract fiber: you would be taking away something that was never added in. The "subtract the fiber" rule is real, but it applies in the United States and in Canada.

There the "Total Carbohydrate" heading includes it, and the label shows the fiber separately as well [10]. The confusion can reach you through an app that uses American databases, through a product imported from there, or through educational material translated without adaptation. If you subtract fiber from an EU label, the insulin dose comes out too small and blood glucose rises after the meal. The difference matters most with bran bread, legumes and whole grains [11].

It means that the manufacturer has not put in sugar or any other ingredient used for sweetness, such as honey or fruit juice concentrate. It does not mean that the product has no carbohydrate. The naturally occurring sugars are still there, and the label has to warn you about it. A fruit juice can have around 10 g of carbohydrate per 100 ml, even though nobody added any sugar to it [12].

The claim "sugars-free" may be used if there are no more than 0.5 g of sugars per 100 g or per 100 ml of product. "Reduced sugars" in fact indicates a reduction of at least 30% compared with a similar product. Both products can still have a great deal of carbohydrate per 100 g, though. That is why it is so important to read the label carefully, not just the front of the package [13].

Usually not. The special category of dietary foods for diabetes disappeared from European legislation in 2016. There were no scientific arguments for separate composition rules [14]. These products are ordinary foods today, with the same label as any other and with no obligation whatsoever to contain less carbohydrate.

The typical case is chocolate or cookies in which the sugar has been replaced by polyols, while the flour and the fat have stayed [4]. The carbohydrate value changes little, the price goes up, and large amounts of polyols can cause bloating [15]. Treat them like any other product: compare the "Carbohydrate" line per 100 g with that of an ordinary version.

You fall back on estimation, and the situation is not rare at all [16]. Foods sold loose, at the bakery or at the market, only have to show the allergens by law. When a food business does give nutrition values, it may use a short form — energy, fat, saturates, sugars and salt — without the "Carbohydrate" line. Unprocessed single-ingredient foods, herbs and spices and very small packages are exempt as well.

You have three aids at hand:

• food composition tables and the apps built on them give you an average value [17];
• the reference foods you already know, such as a 30 g slice of bread, which means 15 g of carbohydrate;
• the restaurant plate, which you break down mentally into its components and estimate one by one [18].

They are average values, not measurements of the package in front of you [19]. The manufacturer can obtain them from a laboratory analysis of the product, from a calculation based on the ingredients or from generally accepted tables. European rules allow fairly wide deviations, which depend on the amount of carbohydrate per 100 g:

• under 10 g — a deviation of no more than 2 g;
• between 10 and 40 g — a deviation of no more than 20%;
• over 40 g — a deviation of no more than 8 g [20].

The deviations come from the natural variation of the raw material, from baking, from moisture and from the rounding of figures. Even so, the label stays accurate enough for the final insulin dose calculation [2]. The largest mistakes almost always come from a badly judged portion, not from the label [18]. If a product surprises you every single time, give it more time for measurements with the kitchen scale and adapt to what you find.