How to Read Food Labels and Choose Healthier Products

In brief: to read food labels well, compare products per 100 g, not per portion. A food is high in sugar above 22.5 g per 100 g and low at 5 g or less. On colored front-of-pack labels, mostly green and amber is the healthier pick, and red marks a food to eat less often. Then check the ingredients list: whatever is listed first makes up the most of the product.

How to Read Food Labels in Five Steps

Reading a label takes under a minute once you know where to look. Work through it in this order:

1. Find the per 100 g (or 100 ml) column. Every pre-packed food carries it, so it is the fair way to compare two brands.
2. Check the front-of-pack colors, if there are any, for a quick verdict on fat, saturated fat, sugars and salt.
3. Look at the reference intake percentages to see how much of a typical day's allowance one portion uses.
4. Compare the portion size with what you really eat. The maker's portion and yours are often different.
5. Scan the first three ingredients. They tell you what the product is mostly made of.

The rest of this guide explains each step, with the numbers you need.

What the Back-of-Pack Nutrition Table Shows

The nutrition table, usually printed on the rear panel, is the most complete part of the label. In the UK it must list energy in both kilojoules (kJ) and kilocalories (kcal), plus fat, saturates, carbohydrate, sugars, protein and salt. Fiber and other nutrients are optional extras.

Values are always given per 100 g or per 100 ml. Many packs add a per-portion column too. Use per 100 g for comparing products and per portion for counting what you eat.

Two rows need extra care:

• "Carbohydrate, of which sugars" is total sugar from every source, including the natural sugar in milk and fruit. It is not the same as added or "free" sugar.
• "Carbohydrate" on its own includes starch, so you can't use it to judge sweetness.

The energy figure comes from fixed factors set in food law: 4 kcal per gram of carbohydrate or protein, 9 kcal per gram of fat, 7 kcal per gram of alcohol and 2 kcal per gram of fiber. That's why fatty foods climb in calories so quickly.

High, Medium or Low: The UK Cut-Offs

UK guidance sets fixed thresholds for calling a food high or low. Anything between the two is medium.

Nutrient (per 100 g of food)	Low	High
Total fat	3 g or less	More than 17.5 g
Saturated fat	1.5 g or less	More than 5 g
Total sugars	5 g or less	More than 22.5 g
Salt	0.3 g or less (0.1 g sodium)	More than 1.5 g (0.6 g sodium)

For sugars there is also a per-portion test: more than 27 g of sugar in one portion counts as high even when the per 100 g figure doesn't. Drinks are judged against different criteria, so these food thresholds don't apply to them.

Traffic-Light Labels on the Front of the Pack

Many supermarkets and brands add a front-of-pack panel that repeats energy, fat, saturates, sugars and salt for one portion. Some color each nutrient:

Color	Meaning	How often
Green	Low	A good choice any day
Amber	Medium	Fine for most of the time
Red	High	Less often, and in smaller amounts

When two similar products sit side by side, the practical rule is simple. Choose the one with more green and amber and fewer reds. A single red doesn't make a food off-limits. It tells you that this food is a big source of that nutrient, so it works best as an occasional choice.

Reference Intakes: What the Percentages Mean

Reference intakes (RIs) are benchmarks for an average adult's daily diet. They are not personal targets. Front-of-pack panels show each nutrient in a portion as a percentage of its RI.

Nutrient	Adult daily RI	Roughly a third, for one meal
Energy	2,000 kcal (8,400 kJ)	About 670 kcal
Protein	50 g	About 17 g
Carbohydrate	260 g	About 87 g
Sugars (all)	90 g	30 g
Fat	70 g	About 23 g
Saturates	20 g	About 7 g
Salt	6 g	2 g

The 90 g sugars figure covers all sugars. Within it, UK advice allows no more than 30 g of free sugars for adults. If your own calorie needs are well above or below 2,000, the percentages will over- or understate your share. Your macro calculator result gives a personal protein, carb and fat budget to compare against instead.

How to Read Food Labels in the US: %DV and Serving Size

On the US Nutrition Facts label, the percent Daily Value (%DV) does the same job as the UK reference intake. It shows how much one serving adds to a full day. 5% DV or less is low, and 20% DV or more is high. Calories appear in large bold type, and added sugars now have their own line.

The serving size reflects the amount people typically eat or drink at one time. It isn't advice on how much you should have, and many packages hold more than one serving.

The Ingredients List and Hidden Sugars

Ingredients are listed by weight, heaviest first. If cream, butter or oil appears in the first few, the product is likely to be high in fat. If sugar is near the top, it is probably high in free sugars.

Sugar often hides under other names. Watch for glucose, fructose, sucrose, dextrose, maltose, corn syrup, high-fructose corn syrup, honey, molasses, treacle, maple or agave syrup, nectars, and fruit juice concentrate. Several of these in one list add up. Allergens in the list are always shown in bold. Our guide to how much sugar per day explains which sugars count toward the daily limit.

A Worked Example: Comparing Two Yogurts

Say you're choosing between two 150 g pots of fruit yogurt.

Per 100 g	Yogurt A	Yogurt B
Fat	3.5 g (amber)	2.5 g (green)
Saturates	2.2 g (amber)	1.6 g (amber)
Sugars	13.0 g (amber)	7.0 g (amber)
Salt	0.2 g (green)	0.2 g (green)

Both pots look similar per 100 g. Now scale to one 150 g pot:

• Yogurt A: 13.0 × 1.5 = 19.5 g sugars, or 19.5 ÷ 90 = about 22% of the sugars RI.
• Yogurt B: 7.0 × 1.5 = 10.5 g sugars, or about 12% of the RI.

Yogurt B saves 9 g of sugar a pot. Some of the sugar in both comes from milk, which isn't free sugar. The ingredients list tells you how much was added: if sugar sits second, after milk, much of it is added.

You can also sanity-check calories from the macros. A food with 5 g protein, 14 g carbohydrate and 3.5 g fat per 100 g provides about 5 × 4 + 14 × 4 + 3.5 × 9 = 107.5 kcal per 100 g (about 450 kJ).

Limits and When to Get Advice

Labels describe a single product. They can't tell you whether your whole diet is balanced, and the RIs are averages that don't fit children, pregnant women or people with high energy needs. If you're managing diabetes, kidney disease, high blood pressure or a food allergy, a doctor or registered dietitian can tell you which label lines matter most for you. To place labels in a wider plan, read how to count calories.

Frequently Asked Questions

What is the most important thing to look at on a food label?

Start with the per 100 g column, because it lets you compare any two products fairly. Then check sugars, saturated fat and salt against the high and low cut-offs, or simply count the reds on a traffic-light panel. Finally, look at the portion size and ask whether it matches the amount you actually eat.

How do you read food labels for healthy eating?

Aim for products that are mostly green or amber, choose whole foods where possible, and use reds as occasional choices. Check that sugar or fat isn't among the first ingredients. Healthy eating depends on the whole day, so use labels to make better swaps within meals you already enjoy, rather than to judge single foods as good or bad.

Is "total sugars" the same as added sugar?

No. On UK labels, "of which sugars" includes natural sugars from milk and whole fruit as well as sugars added during manufacture. A plain yogurt can show several grams of sugar with none added. US labels list added sugars on a separate line. On UK packs, use the ingredients list to judge how much sugar was added.

What does 20% of your reference intake mean?

It means one portion supplies a fifth of the amount an average adult is advised to have in a day, based on a 2,000 kcal diet. For example, 20% of the salt RI is 1.2 g. If you eat less than 2,000 kcal a day, that portion uses a bigger share of your own needs.

Ready to set your own daily targets? Use the macro calculator to turn your calories into grams of protein, carbs and fat.