I have been trying to understand the UK "Traffic Light" system of labelling food nutrition as a helpful guide to maintaining a healthy diet and to focus this question on one nutrient, I am concentrating on saturated fats.

The UK guidelines state that the RDA for saturated fats is 30g per day for men and 20g per day for women.

If you take the following labels I have photographed, they are confusing.

Note that each pack is a portion size pack

The top one is a pack of sandwiches (2 slices of bread, with filling, cut in half), the bottom one is a "crunch mix" snack.

Traffic Light Label for a sandwich pack

Traffic Light Label for a snack size pack of "crunch mix"

How can one of these be low on saturates at 2.2g per portion (11% RDA) when the other pack is "medium level" at 1.2g per portion (6% RDA and 55% of the "low" pack)?

  • Look at the info on the back of the pack instead, that's properly regulated, per 100g. That stuff on the front is designed to confuse. I ignore it completely. '% of an adult's reference intake' is not a hard reference. Values/100g are.
    – Tetsujin
    Commented Mar 22, 2022 at 18:37
  • It's normalizing with respect to calories.
    – eps
    Commented Mar 23, 2022 at 5:14

2 Answers 2


With much government information they do not like to give us firm details of what they do. I have failed to find details of how they do it [1], but one way they could would be to assume a person ate only this, and see how much saturated fat they would eat. The top is 398kcal and 2.2g sat fat, the bottom 159 kcal and 1.2g sat fat. If one ate 2,000 kcals worth of the top you would get 11g of saturated fat, and of the bottom 15g saturated fat. This could indicate that the bottom is worse than the top.

[1] The closest I found was the last page of this document, but that states for sturated fat the limits are low < 1.5g < medium < 5g < high but this is not consistent with your images.

  • You may be onto something here, but your math is off. If you ate 2000 calories of the sandwiches, you'd consume around 45g of saturated fat. If you ate that much of the crunch mix, you'd get 123g of saturated fat!
    – FuzzyChef
    Commented Mar 22, 2022 at 5:37
  • @FuzzyChef (2000/398)*2.2 = 11.05528, (2000/159)*1.2 = 15.09434
    – User65535
    Commented Mar 22, 2022 at 9:08
  • Oh, right, I was looking at "fat" not "saturates".
    – FuzzyChef
    Commented Mar 22, 2022 at 21:08

I suspect that the issue is that the numbers are ‘per pack’ while the colors are per some other concept, possibly a ‘serving’, with the upper product having more than one serving per pack.

If you look at the information below the colors, it gives kCalories per 100g. From this we can determine one is a roughly 200g package while the other is labeled as being 30g. So the lower package would have significantly more saturated fat in an equal measure of the products by weight.

  • As noted in the question, each pack is one portion/serving. The top one is a pack of sandwiches (2 slices of bread, with filling, cut in half), the bottom one is a "crunch mix" snack Commented Mar 21, 2022 at 15:40
  • Right, but as Joe points out, the size of each pack is not the same. British nutrition may be using an absolute serving size of 100g
    – FuzzyChef
    Commented Mar 22, 2022 at 5:38

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