General information only, not medical or dietary advice. If you have a health condition or specific dietary needs, speak to a doctor or registered dietitian.
This guide is for a busy shopper standing in a supermarket aisle with two boxes of cereal in hand, trying to work out which is the better choice before the toddler in the trolley loses patience. You do not need a nutrition degree to read a food label. You need to know where to look first, which numbers matter, and which claims on the front of the pack to ignore.
The guidance below is based on the US Food and Drug Administration’s explainer on how to understand and use the Nutrition Facts label. Labels in other countries look different, often using traffic-light colours or per-100g figures, but the same habits translate.
Ignore the front of the pack, at first
The front of a package is advertising. Words such as “natural”, “wholesome”, “made with real fruit” or “multigrain” are marketing language, and some have little or no regulated meaning. A cereal can be “made with whole grains” and still contain more sugar than grain.
Turn the box over before you form an opinion. The Nutrition Facts panel and the ingredients list are the regulated parts of the label, and they are where the useful information lives.
Step one: check the serving size
Every figure on the panel refers to one serving, so the serving size comes first. The FDA advises looking at both the serving size and the number of servings per container. It also points out that the serving size reflects the amount people typically eat or drink. It is not a recommendation of how much you should have.
Why it matters
The FDA’s own example is a bag of pretzels with three servings per container. If you eat the whole bag, as many people do, you get three times the calories, sodium and everything else shown in the main column. Some packages now show two columns, per serving and per package, which makes this easier.
What to do
Compare your realistic portion with the listed serving. If you will eat double, double every number in your head before reading further.
Step two: glance at calories
Calories tell you how much energy a serving provides. The FDA notes that 2,000 calories a day is used as a general guide for nutrition advice, while individual needs vary with age, sex, height, weight and activity. For quick comparisons between two similar products, calories per serving, adjusted for your actual portion, are a reasonable first filter.
Step three: use the 5/20 rule on % Daily Value
The % Daily Value column is the most useful shortcut on the label, and it is often ignored. It shows how much a serving contributes to a day’s total for each nutrient, based on the reference values the FDA sets. The FDA gives a simple general guide:
- 5% DV or less of a nutrient per serving is considered low
- 20% DV or more of a nutrient per serving is considered high
That rule lets you judge a product in seconds without memorising grams.
Nutrients to keep lower
The FDA suggests choosing foods lower in %DV for saturated fat, sodium and added sugars. Its worked example notes that a product with 37 percent DV for sodium is a high-sodium product, since it is above 20 percent.
Nutrients to get more of
The FDA suggests choosing foods higher in %DV for dietary fibre, vitamin D, calcium, iron and potassium, nutrients many people do not get enough of.
Five percent or less is low. Twenty percent or more is high. That one rule does most of the work.
The reference values behind the percentages
If you want to understand where the percentages come from, the FDA publishes the Daily Values used on the label. A few of the most useful, based on a 2,000-calorie diet:
| Nutrient | Daily Value | Goal |
|---|---|---|
| Saturated fat | 20 g | Less than |
| Sodium | 2,300 mg | Less than |
| Added sugars | 50 g | Less than |
| Dietary fibre | 28 g | At least |
| Calcium | 1,300 mg | At least |
| Iron | 18 mg | At least |
| Potassium | 4,700 mg | At least |
| Vitamin D | 20 mcg | At least |
So a yoghurt with 12 grams of added sugars contributes about a quarter of the daily limit in one pot, which the %DV column will show as 24 percent.
Step four: read the ingredients list
The panel tells you how much of each nutrient is in the food. The ingredients list tells you what the food is made of. Ingredients are listed in descending order by weight, so the first few items make up most of the product.
Look at the first three
If sugar, refined flour or oil appears in the first three ingredients of something sold as a healthy snack, the front-of-pack message deserves scepticism.
Spot sugar under other names
Added sugar appears under many names: cane sugar, corn syrup, dextrose, fructose, glucose, honey, maltose, molasses, rice syrup and fruit juice concentrate, among others. A product can list several different sugars, each lower down the list, which hides how much sugar it contains in total. The added sugars line on the panel cuts through this.
Check for allergens
US law requires the major food allergens to be declared on the label, either in the ingredients list or in a separate “Contains” statement. If anyone in your household has a food allergy, read this every time, because recipes change.
Comparing two products side by side
Most real decisions are comparisons: this bread or that one, this soup or the other. A consistent approach makes them fast.
Match the serving sizes
Two brands may use different serving sizes. Adjust in your head, or compare the per-package columns.
Pick your two priorities
Rather than weighing every line, decide which two nutrients matter most for that type of food. For bread, fibre and sodium. For yoghurt, added sugars and calcium. For soup, sodium.
Use the percentages
Compare %DV for your two priorities and choose accordingly. This takes less time than reading the front of both boxes.
Common label traps
- “Reduced fat” versions sometimes contain more sugar or salt to make up for lost flavour. Check the panel.
- “No added sugar” means none was added; the product can still be high in natural sugars, such as fruit juice.
- “Multigrain” means more than one grain, not necessarily whole grain. Look for “whole” as the first word of the first ingredient.
- Tiny serving sizes on snacks and drinks can make figures look modest. Compare with what you will actually eat.
- “Gluten-free” or “organic” describe specific attributes. Neither means low in sugar, salt or calories.
Labels outside the United States
If you shop in the UK, the EU, Australia or elsewhere, the panel will look different, but the habits carry over.
Per 100 g columns
Many labels outside the US show nutrients per 100 grams as well as per portion. That column makes comparisons between brands far easier, because the serving sizes no longer matter. Compare the per-100 g figures first.
Traffic-light colours
UK front-of-pack labels use red, amber and green for fat, saturated fat, sugars and salt. They are a quick filter: more greens and ambers than reds is a rough sign of a better everyday choice. Check the back panel for the full picture.
Reference intakes
Some countries show “% RI” (reference intake) in place of % Daily Value. The idea is the same: the share of a typical adult’s daily amount that one portion provides.
Reading labels for children
Children’s needs differ from the 2,000-calorie reference used on US labels, so the percentages are a rough guide rather than an exact measure for a small child. Still, a few checks are worth making on foods marketed to children:
- Added sugars in breakfast cereals, yoghurts and drinks, which are often far higher than the cartoon packaging suggests
- Sodium in crackers, ready meals and processed meats
- The first ingredient in snack bars and pouches, which should ideally be a whole food rather than a sugar or syrup
A paediatrician or registered dietitian can give guidance for a specific child.
A one-minute routine for the aisle
Use this checklist on any packaged food:
- Turn the pack over before forming an opinion
- Check the serving size against what you will really eat
- Note calories per realistic portion
- Find saturated fat, sodium and added sugars: aim for 5% DV or less where you can
- Find fibre, calcium, iron, potassium and vitamin D: 20% DV or more is a good sign
- Read the first three ingredients
- Check the allergen statement if it matters in your household
Takeaway
Read the back, not the front. Start with the serving size, then use the 5/20 rule on % Daily Value to judge each nutrient at a glance, and finish with the first three ingredients. With a little practice, the whole routine takes less than a minute and works on almost anything in a packet.
