Start With Serving Information
Nutrition Facts values usually apply to one labeled serving. A package can contain more than one serving, and serving size describes the amount people typically consume—not how much a person should eat. Compare your portion with the label before multiplying calories or nutrients. See Source 1 below.
Use Percent Daily Value
Percent Daily Value (%DV) helps compare how much a nutrient in one serving contributes to a reference daily diet. FDA's general guide is:
- 5% DV or less: low
- 20% DV or more: high
Use the same serving size when comparing products. %DV is a reference tool, not an individualized target.
Total Sugar and Added Sugar Are Different
Total Sugars includes naturally occurring and added sugars. “Includes X g Added Sugars” identifies the added amount. A product can contain natural sugar even when added sugar is zero.
Check the Ingredient List
Ingredients are listed in descending order by weight. Use the list to check allergens and understand what contributes to the product. A short list is not automatically healthier, and a long list is not automatically harmful.
Rounding and FuelForm
Label rules allow rounding, so calories calculated from displayed macros may not match the printed calorie number exactly. For packaged food, log the label's serving and your actual quantity; FuelForm values remain estimates.
The Bottom Line
Read serving size first, then use %DV, added sugars, and the ingredient list to compare products in context.
What does "per 100 g" tell you that "per serving" hides?
Serving sizes are set by the manufacturer, and they are the most manipulable number on the panel. Two competing products can look very different purely because one declares a 30 g serving and the other 45 g.
This is why the "per 100 g" column, mandatory on packaged food in the UK and EU and increasingly available elsewhere, is the more useful one. It is a fixed denominator, so it makes products directly comparable without arithmetic.
A rough reference for reading it at a glance, based on the front-of-pack traffic-light thresholds used in UK labelling — per 100 g of food:
| Nutrient | Low (green) | High (red) |
|---|---|---|
| Fat | ≤ 3.0 g | > 17.5 g |
| Saturated fat | ≤ 1.5 g | > 5.0 g |
| Total sugars | ≤ 5.0 g | > 22.5 g |
| Salt | ≤ 0.3 g | > 1.5 g |
Drinks use lower thresholds, because a serving is larger.
The one caveat: per-100 g comparisons mislead across categories with very different water content. Comparing a dry cereal to a yoghurt per 100 g tells you mostly which one contains more water. Within a category — cereal against cereal, sauce against sauce — it is the honest comparison.
What is the difference between total sugars and added sugars?
The Nutrition Facts panel in the US separates "Total Sugars" from "Includes X g Added Sugars". Most other labelling regimes declare only total sugars. The distinction matters more than almost anything else on the panel.
Total sugars includes lactose in milk and fructose in fruit — sugars arriving inside a food matrix with water, fibre and micronutrients, which behave differently and which no major guideline asks you to restrict.
Added sugars, and the wider category the World Health Organization calls free sugars, covers sugar added by a manufacturer, cook or you, plus what is naturally present in honey, syrups and fruit juice. WHO makes a strong recommendation to keep free sugars below 10% of daily calories, and a conditional one that below 5% — around 25 g a day — is better.
The practical consequence: plain yoghurt showing 8 g of sugar per 100 g has essentially no free sugar, because it is all lactose. A fruit yoghurt showing 13 g has roughly 5 g of added sugar in it. The total-sugar figures look similar; the products are not. Where the label does not split them, the ingredients list is the only way to tell.
How do you read an ingredients list properly?
Ingredients are declared in descending order by weight, which makes the list a rough recipe. Three things are worth knowing beyond that.
Sugar gets split to move it down the list. A product containing 20 g of sugar declared as a single ingredient would appear near the top. Split across glucose syrup, dextrose, fruit juice concentrate and invert sugar, each individual entry is small enough to sit further down — and the product reads as though sugar is a minor component. Anything ending in -ose, anything described as a syrup, nectar, malt or juice concentrate, is sugar.
"Made with real fruit" is a claim about presence, not quantity. In the EU and UK, a percentage declaration is required for an ingredient emphasised on the front of the pack, so a bar advertising strawberries must say how much strawberry it contains. It is frequently in the low single digits.
Watch what is measured before cooking. Weights on the panel refer to the food as sold. A dried product rehydrates; a raw meat product loses water and concentrates. Per-100 g figures on dry pasta and cooked pasta are not comparable.
Which label claims are regulated and which are marketing?
Roughly speaking: nutrient content claims are defined in law, and lifestyle claims are not.
Legally defined, with thresholds: low fat, fat free, low sugar, sugar free, no added sugar, low salt, source of fibre, high in protein, light/lite, reduced. Each has a specific numerical bar the product must clear.
Not defined, or much weaker than they sound: natural, all natural, wholesome, clean, artisan, superfood, and — the most misleading of the set — "no added sugar", which is a real claim but says nothing about total sugar. A fruit juice with no added sugar can carry more free sugar per 100 ml than a soft drink, because juicing releases sugar from the fruit matrix and WHO counts it as free sugar regardless.
Two rounding rules are worth carrying around, because they create genuinely misleading zeros. In US labelling, trans fat under 0.5 g per serving may be declared as 0 g, and calories under 5 per serving may be declared as zero — which is how a cooking spray that is essentially pure oil is marketed as calorie-free. In both cases the ingredients list gives it away when the panel does not: partially hydrogenated oil in the list means trans fat is present regardless of the zero.
Common questions
What is the difference between total sugars and added sugars on a label?
Total sugars includes naturally occurring sugars such as lactose in dairy and fructose in whole fruit. Added or free sugars covers what a manufacturer, cook or you put in, plus honey, syrups and fruit juice. WHO's under-10% recommendation applies to free sugars only. Where a label declares only total sugars, the ingredients list is the way to tell them apart.
Is "per 100 g" or "per serving" more useful?
Per 100 g, for comparing products, because serving sizes are chosen by the manufacturer and vary between competing brands. Per serving is more useful for working out what you personally will eat. The per-100 g comparison only holds within a category — comparing foods with very different water contents mostly compares water.
Does "no added sugar" mean a product is low in sugar?
No. It means nothing was added during manufacture, and says nothing about total sugar. Fruit juice is the clearest example: it can carry as much free sugar per 100 ml as a soft drink, because juicing releases sugar from the fruit and WHO counts juice sugar as free sugar.
Can a product labelled zero trans fat still contain trans fat?
Yes. US labelling permits rounding to 0 g when a serving contains under 0.5 g, so several servings can add up to a meaningful amount. If "partially hydrogenated oil" appears in the ingredients list, trans fat is present whatever the panel says.