How to Read Nutrition Labels: A Dietitian's Complete Guide to Decoding Food Packaging

The single most important — and most manipulated — element of a nutrition label is the serving size. All the numbers on the label (calories, fat, sodium, sugar) refer to one serving, which is often far smaller than what a person actually eats.

Classic examples: a standard bag of crisps may list a serving as 30g (about 10 crisps) when the bag contains 150g. A bottle of juice may state 'per serving (250ml)' when the bottle is 750ml — meaning you need to triple every number for a realistic picture.

The rule: always check how many servings are in the package and multiply accordingly. If a serving is 100g and you eat 300g, every nutrient value triples.

The % Daily Value (%DV) tells you how much a nutrient in one serving contributes to a 2,000-calorie daily diet. The key rule of thumb:

• **5% DV or less = LOW** (good for sodium, saturated fat, added sugar) • **20% DV or more = HIGH** (good for fibre, vitamins, minerals; bad for sodium, saturated fat, added sugar)

For nutrients you want MORE of (fibre, vitamin D, calcium, iron, potassium): aim for 20%+ per serving. For nutrients you want LESS of (sodium, saturated fat, added sugar): avoid anything above 10–15% per serving.

Note: %DV is based on a 2,000-calorie diet. If you eat significantly more or less than 2,000 calories, your actual requirements will differ.

Ingredients are listed in descending order by weight — the first ingredient is present in the largest amount. This one rule unlocks a huge amount of information:

**Check ingredient #1–3:** If the first three ingredients are refined flour, sugar or a form of oil, the product is predominantly those things regardless of health claims on the front.

**Count the types of sugar:** Sugar has over 60 names on ingredient lists — sucrose, high-fructose corn syrup, dextrose, maltose, evaporated cane juice, fruit juice concentrate, agave nectar and many more. Manufacturers sometimes use multiple types specifically to push each one further down the list, making sugar appear less prominent.

**Shorter ingredient lists aren't always better**, but they're a useful proxy. Whole oats (1 ingredient) vs a breakfast bar with 28 ingredients — the comparison is informative even if not definitive.

**Look for whole food first ingredients:** 'Wholegrain wheat' before 'wheat flour', 'olive oil' before 'vegetable oil blend', 'rolled oats' before 'modified starch'.

Front-of-pack claims are marketing, not medicine. Here's how to decode the most common ones:

**'Reduced fat'** means at least 25% less fat than the original product — but the original may have been extremely high in fat, making the 'reduced' version still high. Worse, reduced-fat products often compensate with added sugar or starch.

**'Low calorie'** means ≤40 calories per serving in the US. Remember: if serving size is manipulated, 'low calorie' per serving is meaningless.

**'Natural'** has no legal definition in most countries. It's a marketing term.

**'Multigrain'** means multiple grains — not wholegrain. A multigrain bread may be made primarily from refined white flour with small amounts of other grains added.

**'No added sugar'** means no sugar was added during processing, but the food may still contain significant natural sugars (from fruit concentrate, for example) or artificial sweeteners.

For busy shopping trips, use this rapid framework:

1. **Serving size vs package size** — is a realistic serving = 1 serving on label? 2. **Sodium** — is it below 300mg per serve? (For most snacks/processed foods aim for <15% DV) 3. **Added sugar** — is it 5g or less per serve? (WHO recommends <25g/day total) 4. **Fibre** — is there at least 3g per serve? (A meaningful fibre source) 5. **Protein** — for a meal or snack, does it contain at least 5–10g? 6. **Ingredient #1–3** — is it a whole food?

If a product passes 4 out of 6 of these checks, it's likely a reasonable choice.