Nutrition labels appear on nearly every packaged food, yet research shows most people find them confusing or ignore them. Understanding the key figures helps you make informed choices without obsessing over every meal.
Per 100g vs Per Serving
Per-100g figures allow direct comparison between products regardless of packaging, making them the most useful numbers when choosing between similar items. Per-serving figures show what you actually consume in a realistic portion — though manufacturer-defined servings are often smaller than what people actually eat.
UK Traffic Light Thresholds (per 100g)
| Nutrient | Low (Green) | Medium (Amber) | High (Red) |
|---|---|---|---|
| Total fat | ≤3g | 3-17.5g | >17.5g |
| Saturated fat | ≤1.5g | 1.5-5g | >5g |
| Sugars | ≤5g | 5-22.5g | >22.5g |
| Salt | ≤0.3g | 0.3-1.5g | >1.5g |
Energy and Daily Reference Intake
Average daily energy: ~2,000 kcal (women) / ~2,500 kcal (men)
1 kcal = 4.18 kJ
Spotting Hidden Added Sugars
Long ingredient lists often hide multiple sugar types under different names: sucrose, glucose syrup, fructose, maltose, dextrose, and fruit juice concentrate are all added sugars. Listing them separately makes each appear lower on the ingredients list than if combined as one entry.
Using Labels Practically
The most useful habit is comparing per-100g figures when choosing between similar products — two brands of pasta sauce, two breakfast cereals, two ready meals in the same category. This turns a vague sense that "one might be healthier" into a concrete, checkable comparison that takes only a few seconds at the shelf.
Focus on the two or three figures most relevant to your own situation rather than trying to optimise every number on the label simultaneously. If you're managing blood pressure, prioritise salt. If you're managing weight, prioritise energy and protein. If you're managing cardiovascular risk more broadly, prioritise saturated fat alongside salt. Trying to minimise every figure at once usually leads to analysis paralysis in the supermarket aisle — picking the figures that matter most for your specific goals and using those consistently is far more sustainable.
Compare per-100g figures when choosing between similar products — two pasta sauces, two cereals, two ready meals. Focus on the 2-3 figures most relevant to your health goals (energy and protein for weight management, salt and saturated fat for cardiovascular health) rather than trying to optimise everything simultaneously.
Reading Ingredient Lists Alongside Labels
Ingredients on UK and EU packaging are listed by weight, from the largest quantity to the smallest, which means the first two or three ingredients typically make up the bulk of the product. A cereal listing sugar as the second ingredient, ahead of the named grain itself further down the list, tells you something significant about its actual composition that the nutrition panel alone might not make immediately obvious at a glance.
Long ingredient lists with numerous unfamiliar additives aren't automatically problematic — many serve legitimate functions like preserving freshness or maintaining texture — but a notably shorter list with recognisable, whole-food ingredients is generally associated with less heavily processed products. Combining a quick scan of the ingredient list with the nutrition panel gives a more complete picture than relying on either source alone, particularly for products marketed with health claims on the front of the pack that aren't always fully reflected in the actual nutritional content.