Most people check one thing on a food label: calories. Learning how to read food labels properly means looking at several numbers together, not just one. A food can be low in calories and still be high in added sugar. Another can be “low fat” but loaded with salt to make up for the lost flavour. Nutritionists read labels differently, and the method isn’t complicated once you know what to look for.
This article walks through exactly what to check, in what order, and how to spot the marketing tricks that make less healthy foods look better than they are.
For more on how food choices connect to inflammation in the body, read our guide on Inflammation 101: How to Know if You Have It and What to Eat Next.
How to Read Food Labels: Start With the Serving Size
Before looking at any number on the label, check the serving size first. Every other figure on the label — calories, sugar, fat, salt — is based on that one serving. Many packages contain more than one serving, even when they look like a single portion.
A bag of chips might list 150 calories per serving, but if the bag contains two and a half servings, eating the whole bag means 375 calories, not 150. This single step is the one most people skip, and it changes every other number on the label.
How to Read Food Labels: Check the Ingredients List, Not Just the Front
The front of the package is marketing. The ingredients list is the truth. Ingredients are listed by weight, from most to least. Whatever is listed first makes up the largest portion of the product.
If sugar, corn syrup, or a refined oil appears in the first three ingredients, that tells you more than any front-of-pack claim like “natural” or “wholesome.” Sugar also hides under many different names, which makes ingredient lists easy to misread if you don’t know what to look for.
Common hidden names for sugar
- high-fructose corn syrup
- dextrose, maltose, and sucrose
- cane juice or cane syrup
- rice syrup or malt syrup
- fruit juice concentrate
A product can list several of these separately, in smaller amounts each, so sugar doesn’t appear first on the list even though the combined total is significant. Scanning for these terms specifically helps you catch what a quick glance would miss.
How to Read Food Labels: Look Past Front-of-Pack Claims
Words like “natural,” “light,” “multigrain,” and “made with real fruit” aren’t strictly regulated the way you might expect. A product can carry these claims while still being high in sugar, salt, or refined carbohydrates. Front-of-pack claims are designed to catch your eye, not to tell the full nutritional story.
The nutrition panel on the back tells you what the front-of-pack marketing won’t. Trust the numbers on the back over the words on the front, every time.
How to Read Food Labels: Understand the Key Numbers
Once you’ve checked serving size and ingredients, these are the numbers worth focusing on.
- Added sugars: look for this specific line, separate from total sugars, since it reflects sugar added during processing rather than sugar naturally occurring in fruit or dairy.
- Fibre: aim for products with at least 3 grams of fibre per serving where relevant, since fibre slows digestion and supports steady energy.
- Sodium: the NHS guideline for high salt content is more than 1.5 grams of salt per 100 grams of food. Processed and packaged foods are the biggest contributors to excess salt intake for most people.
- Saturated fat: the NHS considers more than 5 grams of saturated fat per 100 grams to be high. This differs from total fat, which includes healthier unsaturated fats too.
- Protein: particularly useful to check on snack foods, since higher protein content generally means better satiety per calorie.
How to Read Food Labels: Use the Traffic Light System
Many UK food packages include a red, amber, and green colour-coded label on the front. This system rates fat, saturated fat, sugars, and salt at a glance. Green means low, amber means medium, and red means high for that nutrient.
When comparing two similar products, choosing the one with more green and fewer red ratings is a fast, reliable shortcut, even without reading the full nutrition panel. It won’t replace checking ingredients, but it’s a useful first filter when you’re short on time in the aisle.
Putting It All Together: A Quick Label-Reading Routine
- Check the serving size first, and note how many servings are actually in the package.
- Scan the first three ingredients for sugar, refined oils, or refined grains.
- Check the added sugars line specifically, not just total sugars.
- Glance at sodium and saturated fat against the high-content thresholds above.
- Use the traffic light colours, if present, as a fast comparison tool between similar products.
This routine takes under 30 seconds once it becomes familiar, and it works in any grocery aisle without needing a nutrition app or calculator.
Reading labels well makes meal planning far easier too. Our guide on Meal Prepping for Busy Professionals: A Beginner’s Guide covers how to turn smarter grocery choices into a full week of balanced meals.
The NHS guide to reading food labels provides further detail on nutrition panels and colour-coded labelling.
Key Takeaways
- Understanding how to read food labels starts with the serving size, since every other number on the label depends on it.
- The ingredients list, ordered by weight, tells you more than any front-of-pack marketing claim.
- Sugar hides under many different names, which can make a product’s true sugar content easy to miss at a glance.
- Added sugars, fibre, sodium, and saturated fat are the numbers worth checking beyond total calories.
- The traffic light colour system offers a fast, reliable way to compare similar products when you’re short on time.
Final Thoughts
Learning how to read food labels properly takes a few minutes to learn and seconds to apply once it’s familiar. The goal isn’t to obsess over every number on every package. It’s knowing which few numbers actually matter, so a quick glance tells you what you need to know.
Start with your next grocery trip. Pick two similar products and compare them using this routine. You’ll likely be surprised by what the label reveals once you know where to look.
Read past the front of the box. That’s where the real story is.
Medical Disclaimer: The information on this page is provided for educational and informational purposes only and is not intended as medical advice. It should not replace consultation with a qualified healthcare professional. For full details, please read our Disclaimer.
