The short answer
A label tells you what is in a food and how much. You do not need to read every line.
Look at a few key numbers, compare similar products and choose the one with less sugar, salt and saturated fat, and more fiber.
Most people can do this in under a minute once they know what to look for.
Why reading labels is worth it
The WHO advises limiting free sugars, salt and unhealthy fats. Labels show you how much is in packaged foods, which is where many of us get a lot of them.
The NHS notes that many foods are processed. Labels help you choose the better options within them.
Labels differ from country to country. The thresholds in this guide come from the NHS in the UK, so check the format on your own packs.
The five quick checks
- Serving size. Check what the numbers apply to. A pack may hold several servings.
- Energy. Look at kilocalories (kcal) or kilojoules (kJ), and compare with a similar food.
- Sugars. Look at total sugars, and choose the lower one.
- Salt. Some labels list sodium instead. Salt is about 2.5 times the sodium.
- Saturated fat. Choose foods with less. Then scan fiber and the ingredient list.
Compare foods in the same category, such as two breakfast cereals or two pasta sauces.
Use the per 100 gram column to compare
Pre-packed foods must show nutrition information per 100 grams or 100 milliliters, and sometimes per portion. The NHS says this makes it easy to compare foods fairly.
The NHS gives these guides for what counts as high and low per 100 g:
| Nutrient | High (per 100 g) | Low (per 100 g) |
|---|---|---|
| Total fat | More than 17.5 g | 3 g or less |
| Saturated fat | More than 5 g | 1.5 g or less |
| Total sugars | More than 22.5 g | 5 g or less |
| Salt | More than 1.5 g | 0.3 g or less |
Sodium is shown in some places. The NHS equivalents are more than 0.6 g sodium for high and 0.1 g or less for low.
Traffic light labels
Some packs show colors on the front. Red means high, amber means medium and green means low.
- Mostly green: a healthier choice.
- Amber: fine to eat regularly.
- Red: fine sometimes, but limit how often and how much.
A food with all or mostly green is a healthier choice, according to the NHS.
Read the ingredient list
Ingredients are listed from the largest amount to the smallest. The first few tell you most of the story.
- If sugar or a sugar name is near the top, the food is sweet.
- Sugar goes by many names, such as syrup, glucose, dextrose and honey.
- A short list of recognizable ingredients is often a good sign.
- Look for "whole grain" or "whole wheat" as the first ingredient in breads and cereals.
Want a simple eating plan to go with this?
Our Healthy Eating Guide shows how to combine labels, plates and planning.
Watch the claims on the front of the pack
Words on the front, such as natural, light, or made with whole grain, are marketing. They are not the same as the numbers on the back.
- "Low fat" foods can be high in sugar.
- "Natural" does not mean low in sugar or salt.
- "Made with whole grain" may mean only a little whole grain.
- "No added sugar" can still contain natural sugars.
Flip the pack over and use the five checks.
A worked example: comparing two cereals
Imagine two cereals. The numbers below are invented to show the method.
| Per 100 g | Cereal A | Cereal B | Better pick |
|---|---|---|---|
| Sugars | 28 g (high) | 6 g (amber) | Cereal B |
| Salt | 0.8 g | 0.3 g (low) | Cereal B |
| Saturated fat | 1.0 g (low) | 1.2 g (low) | Similar |
| First ingredient | Sugar | Whole grain oats | Cereal B |
Cereal B wins on sugar, salt and ingredients. Two minutes at the shelf is enough to spot that.
Watch out for serving size traps
A small serving size can make a food look healthier than it is. Always ask how much you will really eat.
- A pack that looks like one serving may hold two or three.
- If you eat the whole pack, multiply the numbers by the number of servings.
- Serving sizes for cereal, snacks and drinks are often smaller than what people pour.
- Use the per 100 gram column to compare, then think about your own portion.
For example, if a bag lists 150 kcal per serving and holds three servings, the whole bag is about 450 kcal.
Look for the good numbers too
Labels are not only about what to limit. They also show what is worth looking for.
- Fiber. Higher is usually better for digestion and fullness.
- Protein. Useful in foods such as yogurt, beans and tofu.
- Short ingredient lists. Often a sign of less processing.
Do not chase a single number. A food that is high in fiber but also very salty may not be the best choice.
Allergens and special diets
Labels also help if you have an allergy or follow a special diet.
- Allergens are usually highlighted in the ingredient list.
- Phrases such as "may contain" warn of possible traces.
- Check the label every time. Recipes can change.
- Ask a doctor or registered dietitian if you have a food allergy or a medical condition.
This is general information. Follow the advice you have been given by your health professional.
Foods worth checking first
You do not need to read every label. Focus on foods where numbers can vary a lot between brands.
- Breakfast cereals and granola.
- Bread and wraps.
- Pasta sauces, soups and ready meals.
- Yogurts, especially flavored ones.
- Sauces, dressings and snacks.
- Drinks, including juices and coffee drinks.
Comparing two or three brands of these can make a real difference to how much sugar, salt and saturated fat you eat over a week.
A two-minute routine for the store
- Pick up the food and flip it over.
- Check the serving size.
- Look at the per 100 gram column for sugars, salt and saturated fat.
- Glance at the first three ingredients.
- Compare with one alternative and choose the better one.
Do this for one or two foods each trip. After a few weeks you will remember your favorite good choices and can skip the reading.
Beyond the label: foods that need none
Many of the healthiest foods come without a label at all. Fresh vegetables, fruit, plain nuts, eggs and dried beans have a single ingredient.
Building most of your plate from these foods makes label reading much simpler. You only need to check the packaged extras.
Label reading in the supermarket
You do not need to read every label. A few smart habits make shopping faster and less stressful.
- Compare similar products side by side, such as two breakfast cereals or two yogurts.
- Use the per-100 g column when comparing, since pack sizes differ.
- Check the ingredients list. Ingredients appear in order of weight, so the first few make up most of the product.
- Watch for different names for sugar, such as syrup or concentrated fruit juice.
- Be careful with front-of-pack claims like "natural" or "light". Check the back.
Pick your priorities
Trying to score everything is tiring. Choose one or two things to watch, such as added sugar in drinks, or salt in ready meals.
Everyone's needs differ. If you have allergies, diabetes, high blood pressure or another condition, follow your doctor's or dietitian's advice.
Do not let labels make eating stressful
Food is more than numbers. Labels are a tool, not a test.
Most of your diet should come from foods that do not need a label, like vegetables, fruit, beans and eggs. For meal ideas, see our guide to building a balanced plate.
A worked example: comparing two yogurts
Imagine two yogurts on the shelf. One is labeled "fruit" and the other is plain.
- Look at the sugar per 100 g. The fruit version may contain a lot more.
- Check the ingredients. If sugar or syrup is near the top, it makes up a large share.
- Look at the protein. Higher protein can help you feel full for longer.
- Choose the option that fits your needs, and add fresh fruit to the plain one if you like sweetness.
You did not need a calculator. You compared two labels on two or three things that matter to you.
Repeat the same quick check for cereals, sauces and snack bars, and you will soon spot patterns.
This is how label reading becomes a quick habit rather than a chore.
Recap: reading labels in five points
- Check the serving size first.
- Compare foods using the per 100 gram column.
- Aim for lower sugar, salt and saturated fat, and more fiber.
- Use traffic lights as a shortcut where they are shown.
- Scan the first few ingredients.
Labels are general tools. If you have diabetes, high blood pressure or another condition, ask your doctor or a registered dietitian which numbers matter most for you.
Nutrition labels: frequently asked questions
Start with the serving size, then compare sugars, salt and saturated fat using the per 100 gram column. Then check fiber and the ingredient list.
The NHS says more than 22.5 g of total sugars per 100 g is high, and 5 g or less is low.
The NHS says more than 1.5 g of salt per 100 g, or 0.6 g of sodium, is high. 0.3 g of salt or less, or 0.1 g of sodium, is low.
Red means high, amber means medium and green means low for fat, saturated fat, sugars and salt. Mostly green is a healthier choice.
Yes. They run from the largest amount to the smallest, so the first few matter most.
No. Formats and reference values differ. The thresholds here come from the NHS, so check the labeling rules where you live.
Sources and further reading
We checked targets and thresholds against these sources. Figures are rounded, and examples are illustrations, not prescriptions.
- NHS: How to read food labels
- NHS: What are processed foods?
- World Health Organization: Healthy diet fact sheet
- NHS: 8 tips for healthy eating
Want more? Head back to the Nutrition hub, or read the Healthy Eating Guide.
