How to read nutrition labels: the guide every consumer needs

The information war in your supermarket

Every time you walk down a supermarket aisle, you face approximately 40,000 different products competing for your attention. A study by the Cornell Food and Brand Lab (Wansink, 2017) found that the average shopper spends 13 seconds reading a label before deciding to buy. Food companies spend billions of dollars optimizing those 13 seconds: colors, claims, marketing words. The result is a system designed to look informative while remaining intentionally confusing. The good news: once you know the 5-step framework below, reading labels takes 20 seconds and saves you from most marketing traps.

What every label field actually tells you

Use the per-100-gram column on every label and apply these healthy thresholds. Anything that exceeds these per-100-g values for sugar, saturated fat or salt is a product to use sparingly, regardless of how the front of the package is marketed:

Step 1: read the ingredient list FIRST, not the nutrition panel

Most people glance at calories first. Wrong move. The ingredient list tells you what the food really is. By law (FDA in the US, EFSA in EU), ingredients must be listed in descending order by weight. The first three ingredients make up the majority of the product. If sugar (or any of its 60+ aliases) appears in the top 3, you are buying mostly sugar.

• Sugar aliases to recognize: high fructose corn syrup, dextrose, maltose, sucrose, fructose, glucose syrup, fruit juice concentrate, agave nectar, brown rice syrup, molasses, evaporated cane juice, maltodextrin, barley malt
• A 2014 University of North Carolina study analyzed 85,451 packaged foods sold in the US and found that 68% contained added sugars, often under names consumers do not recognize
• Rule of thumb: if the ingredient list has more than 5 items or contains words you cannot pronounce, it is likely ultra-processed
• Pay attention to "vegetable oils" without specification — usually palm or soybean oil with high omega-6 content

Step 2: the numbers that actually matter (per 100g, not per serving)

Manufacturers exploit serving size manipulation. A bag of chips might show "150 kcal per serving" but define a serving as 28g when the bag contains 200g. Always look at the per-100g column, which the EU mandates and most countries provide. This lets you compare any two products fairly.

• Calories per 100g: <100 is low energy density, 100-300 is moderate, >400 is high (snacks, sweets)
• Protein: minimum 10g/100g in any product marketed as "protein". For Greek yogurt, aim for 8g+
• Total sugars: <5g/100g is low (PHE traffic light green), 5-22.5g is medium, >22.5g is high (red)
• Saturated fat: <1.5g/100g is low, 1.5-5g is medium, >5g is high
• Fiber: >3g/100g is a "source of fiber", >6g/100g is "high in fiber"
• Salt: <0.3g/100g is low, 0.3-1.5g is medium, >1.5g is high (>2.3g is excessive)
• Sodium-to-potassium ratio: ideal foods have more potassium than sodium

Step 3: decode marketing claims (most are legal lies)

• "Light" or "Lite": only requires 30% fewer calories than the standard version. Light mayo can still have 300 kcal/100g
• "No added sugar": does not mean sugar-free. Fruit juice has zero added sugar but 10g natural sugar per 100ml
• "Whole grain": EU rules allow as little as 51% whole grain flour. Read the ingredient list to verify
• "Natural" or "All Natural": has NO legal definition in most countries. It is pure marketing
• "Source of protein": only requires 12% of calories from protein. A protein bar at 12% is mostly carbs and fat
• "Low fat": often replaced with sugar to maintain palatability. Low-fat yogurts often have MORE sugar than full-fat
• "Gluten-free": does not mean healthy. Many gluten-free products are higher in sugar and fat than the originals
• "Multigrain": just means multiple grains, not whole grains. Could be refined wheat, refined oat, refined rye

Step 4: understand the % Daily Value column

The %DV column is based on a hypothetical 2,000 kcal diet. As a quick rule: 5% or less is "low", 20% or more is "high". Use this to scan for nutrients you want more of (fiber, vitamin D, calcium, iron, potassium) and nutrients you want to limit (saturated fat, sodium, added sugars).

Step 5: real food does not need a label

The single most important nutrition advice from every credible scientific authority (WHO, Harvard School of Public Health, Mediterranean Diet research) is: build your diet around foods that do not need a nutrition label. Vegetables, fruits, eggs, fresh meat, fish, legumes, nuts, plain yogurt, oats. The labels matter most for the 20% of your diet that comes from packaged foods. The other 80% should be whole foods.

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