BLOG BY Alannah Fennessy BSc

How to Combat Misleading Labelling

Food shopping is overwhelming and exhausting at the best of times and reading food labels adds another layer of complexity which requires time, energy and a solid nutritional understanding. Although there is legislation to protect consumers from false claims, there is still room for clever (read: deceiving) marketing, packaging, and branding.  

Food labelling can be mandatory or voluntary, the latter is generally applicable to the front of pack and includes:

Call outs - These draw your attention to a specific ingredient, or lack of, e.g. no artificial colours or flavours or, the more ambiguous e.g. “no nasties[i]

Traffic light labelling This is a voluntary labelling system which indicates whether a food is high, moderate or low in fat, saturated fat, sugar and salt which is correspondingly colour coded with either green, amber or red, which denotes low, moderate or high content respectively[ii].

Health Claims – These are legally protected and regulated and include “high in” and “source of” claims.

Example of Claims Summary Table[iii]

Example of a claimLegislation
Source of protein12% of energy from protein per 100g
High in protein20% of energy from protein per 100g
Source of fibre1.5g fibre per 100kcal3g of fibre per 100g
High in fibre3g fibre per 100cal6g of fibre per 100g
Lighter/Lite/Light/Reduced30% less “x” than the product it is being compared to
No added sugarsThe food does not contain any added mono or di-saccharides (units of sugar) although it may still be high in sugar which occurs naturally in the product.


Our fascination with protein has led to the development of a vast array of protein-rich foods from granola to water. “High in protein” means that at least 20% of the energy per 100g of the product must come from protein. “Source of protein” stipulates a slightly lower requirement of 12% energy per 100g. Since it is based on energy, some energy dense foods such as peanut butter fail to meet the threshold for ‘high protein,’ despite containing 27g protein per 100g.

When sourcing protein in our diet it’s important to ensure we don’t neglect foods which are subject to significantly less glamourous branding and packaging such as meat, fish and eggs which are excellent, complete* sources of protein.

*A complete source of protein means that it contains all of the essential amino acids which are the ‘building blocks’ of protein.  


Products are eligible for “source of fibre” claims if they contain 1.5g fibre per 100kcal or 3g fibre per 100g and “high in fibre” if they contain 6g fibre per 100g or 3g fibre per 100kcal. Considering we need 30g of fibre per day picking up a product which claims “source of fibre,” can deliver as little as 5% of our fibre needs[iv].

As research on our gut microbiome richens and consumer demand for products which enhance our gut health peaks, “prebiotic fibre” claims are appearing on more food products. However, it is important to note that all fibre is prebiotic anyway and capable of stimulating our gut microbiome through fermentation. Therefore, specifically adding “prebiotic” to fibre on food labels is a way to enhance the perceived health benefits of a product and increase our willingness to purchase and/or spend more money.

Traffic Light Labelling

Although traffic light labelling is a good way to capture a food’s nutritional profile at a glance it is just a snapshot and therefore fails to consider other components such as fibre and protein. Similarly, the vitamin and mineral content is neglected. A good example of this is cheese which generally has a red traffic light for fat, saturated fat and salt, but is an excellent source of calcium, phosphorous and protein and can most definitely be consumed as part of a healthy balanced diet.

Serving Size

It is also important to take note of the advertised front of pack nutritional information which may be calculated based on a different portion size to the way it is packaged and sold. This has been observed in some cakes[v] and chocolate bars[vi] which are sold as twin bars or slices, but the nutritional information is for one stick or one piece of cake. If manufacturers want us to eat one piece of chocolate or cake it should surely be sold as one.

Comparative claims

For a food to be declared as “light” it must have 30% less fat or sugar than a similar product to which it is being compared. This means that if the original product is particularly high in fat or sugar that even a 30% reduction is insufficient to make the product “low” or “moderate” in fat or sugar according to traffic light labelling[vii]. It’s important to deconstruct the associations between “lighter” and its accompanying shade of light blue* with “healthy;” as since this claim is comparative, it can only mean “healthier.”

*Simply type “lighter” into any online supermarket website search bar

Mandatory Food Labelling

The nutritional table is something we might take the occasional look at and it is certainly worth interrogating if you wish to investigate a front-of-pack claim a little bit further. The table will include the following information per 100g and per serving although the former is more useful when making comparisons between two products.

EnergyThis appears as both kJ or kcal. Percentages of our calorie intake are based on an average 2000 kcal intake, however, this varies greatly depending on gender and physical activity so should always be taken with a pinch of salt! 
FatThis is the total fat and will be a sum of saturated fat and unsaturated fat. Unsaturated fat is comprised of mono- and poly-unsaturated fat) 
Saturates (of which saturates)This is the amount of fat which is saturated. For example, if total fat is 10g and saturates is 1g we can assume the remaining 9g is unsaturated fat. 
CarbohydrateThis is comprised of starch and sugars, only the ‘sugar’ part is declared below.
Sugars (of which sugars)If total carbohydrate is declared as 10g and sugars is 5g, we can assume starch is the remaining 5g.  
FibreWe should be aiming for 30g per day 
ProteinDepending on our age and exercise regime we should be aiming for around 0.75g-1g per kg of body weight per day. This means if you weigh 70kg you should aim for between 52.5-70g protein per day. 
SaltWe should aim for 6g or less per day.  

The back of pack labelling indicates how much each constituent contributes to your daily allowance of calories, fat, saturated fat, sugar and salt as a percentage. The percentage provided for calories is based on an average adult and fails to consider gender or physical activity which are two key influencers of energy requirements.

Finally, most constituents are allowed + or - 20% variance to the values displayed on the back of the pack due to variation in the ingredients used or the final weight of the product, which too, is liable to some variance, so it is always worth just using this as a guidance and should always be taken with a pinch of salt!

There’s no need to swap your current novel for the side of a cereal box, but it is certainly worth checking that foods you purchase because of a perceived health benefit match the expectations set by their packaging or labelling.

Disclaimer – The food products included here have just been selected as examples.

This blog post was written by Alannah is a Food Science and Nutrition graduate from the University of Leeds who is currently studying for an MSc in Clinical and Public Health Nutrition at UCL. Her interests are cooking and more recently “myth busting” which challenges our perceptions of food, nutrition, and health. You can find her Instagram at @alannah_eats.


[i] https://www.sainsburys.co.uk/gol-ui/Product/the-collective-suckies-strawberry-100g

[ii] https://www.nhs.uk/live-well/eat-well/how-to-read-food-labels/


[iv] https://groceries.asda.com/product/bagels/new-york-bakery-co-4-pre-sliced-original-bagel-thins/910003083721?&cmpid=ppc-_-ghs-_--_-google-_--_-dskwids92700058697479758_dc&s_kwcid=AL!11432!3!459891151410!!!g!1019449318291!&ds_rl=1254319&gclid=CjwKCAiAo5qABhBdEiwAOtGmbrJrqF8dgQkrol53t1W3CMMhWEXfMuXxcnP1qZPnZxD3R9Q_Y9DJaxoCMoEQAvD_BwE&gclsrc=aw.ds

[v] https://groceries.asda.com/product/cake-slices/mr-kipling-bakewell-slices/21039

[vi] https://groceries.asda.com/product/multipack-chocolate/cadbury-twirl-chocolate-bar-4-pack/910000271079


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