How to choose a breakfast cereal without being fooled by the box

Look for a cereal that is wholegrain and unsweetened, and that is low or medium for sugar and salt per 100g. That is the short version of the NHS advice. It suggests unsweetened wholegrain cereals that are not frosted or coated with chocolate or honey, and names plain wholewheat biscuits, plain shredded whole grain and porridge as higher-fibre options. It also warns that many cereal products on sale in the UK are refined, low in wholegrain and can be high in added salt and sugar.

Claims on the front of a box are selective by design. The back has the information needed to compare them, and four checks cover almost everything.

Check 1: what is it mostly made of?

Go to the ingredients. The NHS explains that they are listed in descending order of weight, so the first item is the main one. You want a wholegrain at or near the top: whole wheat, whole oats and so on. Our guide to wholegrain labels explains why "multigrain" does not count.

While you are there, look for how early sugar turns up, and whether it appears in more than one form. Honey and syrups are sugar as far as the free sugars limit goes, however natural they sound on the box.

Check 2: sugars per 100g, then think about where they came from

Compare the "of which sugars" line per 100g. On the NHS scale, 5g or less is low and more than 22.5g is high. Front-of-pack traffic lights also go red at more than 27g per portion.

This figure has a known weakness. It counts all sugars, including those naturally present in fruit and milk. So a muesli with plenty of dried fruit may show a higher number than you would expect, and the ingredients list is how you can tell the difference. The NHS makes this point itself. If the sugar line is high and the list shows sultanas and no added sugar, you are looking at a different product from one with sugar or syrup near the top.

For scale, the adult limit for free sugars is 30g a day, roughly 7 sugar cubes. Children get less: 24g at 7 to 10, 19g at 4 to 6 and 14g at 2 to 3. If children in your house eat the same cereal you do, compare against their number and not yours.

Check 3: salt, the one nobody looks for

Cereal does not taste salty, which is why this line gets missed. The NHS lists breakfast cereals among the everyday foods that together supply around three quarters of the salt we eat. On label thresholds, 0.3g or less per 100g is low and more than 1.5g is high. Adults should have no more than 6g a day in total, and younger children much less, with 3g the limit at 4 to 6 and 2g at 1 to 3.

Check 4: fibre

This is the number you want to be high. A cereal with 6g or more of fibre per 100g counts as high fibre. The British Dietetic Association gives 13g to 24.5g per 100g for shredded wholewheat and bran cereals, against 7.5g for plain oats in the British Heart Foundation's figures, so those are worth a look if you are trying to reach the 30g guideline.

Fibre does not cancel out the rest, though. Read this check together with the other three.

The portion trap

Front-of-pack labels give figures per serving, and the NHS says plainly that the manufacturer's idea of a portion may be different from yours. There are two simple defences:

• When comparing two products, always use the per 100g column. Serving sizes vary, and 100g does not.
• Weigh your usual bowl once, without milk. Then you can scale the per 100g numbers to what you really eat. Most people only need to do this one time per cereal.

A worked example, with made-up numbers to show the method only: a cereal listing 24g of sugars per 100g is over the 22.5g line, so it counts as high. If your bowl weighs 50g, that bowl has 12g of sugars. How much of it is free sugars depends on the ingredients, as Check 2 explains.

Reading the traffic lights

Not every pack has them. Where they appear, the NHS says all or mostly green is generally the healthier choice, mostly amber can be eaten most of the time, and any red means something to limit and have less often. One red does not rule out a food. It simply tells you which part to be aware of.

Traffic lights also do not show fibre or whether a cereal is wholegrain, so a cereal can look fine on the front and still be refined. The ingredients check catches that.

What to do if the family loves the sweet one

Swapping overnight tends to fail. The NHS suggests mixing some wholegrain cereal into your usual one, and if you add sugar, cutting it down gradually. Sweetness can come from sliced banana or berries. Dried fruit on cereal is fine, as it is better for teeth eaten with a meal than as a snack between meals.

Porridge is the other route, since plain oats pass all of these checks without argument. Our porridge piece covers toppings and the flavoured sachets to be wary of. A glass of juice with breakfast counts as well: the NHS limit is 150ml a day for fruit juice and smoothies combined, drunk with a meal.

Should breakfast be cereal at all?

It does not have to be. The NHS's wording is that a healthy breakfast high in fibre and low in fat, sugar and salt can form part of a balanced diet, and that breakfast can help you get the nutrients you need. Wholemeal toast with peanut butter and an orange, one of its worked examples, fits that description without a cereal box in sight.

If you have a condition affected by sugar or salt, such as diabetes or high blood pressure, your GP or dietitian can give advice that fits you. These thresholds are general guidance for reading labels.

This article is general information and is not medical advice. Guidance changes, so check the linked sources for the current figures. Last reviewed 6 October 2026.