How to read nutrition labels for healthier food choices

Food packaging is covered in claims, bright colours and marketing slogans designed to catch your attention. Finding basic facts about what you are eating requires looking past this design to the nutrition label. Supermarket aisles are filled with products claiming to be healthy, low in fat or high in protein. Without checking the label, it is difficult to know if these claims align with your own nutritional requirements. Learning to read the back of a food packet takes a few extra seconds but provides clear information. Once you understand the standard layout of ingredients and nutrient values, comparing products becomes a straightforward task.

Understanding the front and back of the pack

In the UK, food packaging features two main areas of nutritional information. The front of the pack displays a colour summary, while the back contains a detailed grid and an ingredients list.

The front label often uses a traffic light system of red, amber and green. This highlights the amounts of fat, saturated fat, sugars and salt per portion. Green indicates a low amount, amber means a medium amount, and red shows a high amount. If a product has mostly green and amber colours, it is generally a healthier choice. However, the front label is only a summary. It relies on the manufacturer-suggested portion size, which might not match what you actually eat.

To get the full picture, turn the packet over. The detailed nutritional grid provides exact measurements in grams or milligrams. This grid always lists values per 100 grams or 100 millilitres. It removes guesswork and allows you to compare two different products side by side. The grid is a legal requirement, listing energy, fat, saturates, carbohydrates, sugars, protein and salt. Because this grid is standardised, it is a reliable tool in the supermarket.

The 100g rule and portion sizes

When comparing two similar foods, always use the 100g column rather than the per portion column. Manufacturers define their own portion sizes. One brand of cereal might suggest a 30g serving, while another suggests 45g. If you compare their per portion columns, the smaller serving will naturally look lower in sugar and calories. Comparing the 100g columns gives you a fair, direct comparison.

Once you have made your choice, look at the portion column to understand how much you are actually eating. Be realistic about your habits. If a packet of rice claims to contain two portions but you normally eat the entire packet, you need to double the nutritional values listed per portion.

Measuring your food at home using digital kitchen scales is useful. Weighing a 30g portion of cereal helps you visualise a standard serving on your plate. You do not need to weigh everything forever. Doing it consistently for a few weeks trains your eye to estimate portions accurately.

Pay attention to products that look like single servings but contain multiple portions. A small bottle of fruit juice might list nutritional information for half the bottle. If you consume the whole item, you are consuming twice the sugar and energy shown.

Making sense of macronutrients

The nutritional grid breaks down the food into macronutrients. These are the nutrients your body needs in larger amounts: carbohydrates, fats and protein.

Carbohydrates and sugars

The grid lists total carbohydrates, followed by “of which sugars”. Total carbohydrates include both complex carbohydrates and simple sugars. Complex carbohydrates break down slowly, providing sustained energy. The “of which sugars” line tells you how much of that total is made up of simple sugars.

This sugar value includes naturally occurring sugars and added sugars. Milk contains lactose, and fruit contains fructose. These natural sugars are packaged alongside beneficial nutrients and fibre. Added sugars are put into food during processing. The grid does not separate natural from added sugars, so you must use the ingredients list to spot added sugars.

Fats and saturates

Fat is an essential nutrient, but different types behave differently. The label shows total fat, followed by “of which saturates”. Saturated fats are typically solid at room temperature, found in butter, cheese and fatty meats. Health guidelines recommend keeping saturated fat intake low.

Unsaturated fats are generally liquid at room temperature and are found in olive oil, nuts, seeds and oily fish. A higher proportion of unsaturated fat to saturated fat is typically a better choice.

Protein

Protein is vital for tissue repair, muscle maintenance and keeping you feeling full. The grid lists protein in grams. When planning meals, aim for a clear source of protein. Foods like lean meats, fish, eggs, beans, lentils and tofu will show high protein values per 100g.

Decoding the ingredients list

The ingredients list is just as important as the nutritional grid. By law, ingredients must be listed in order of weight. The main ingredient comes first, and the smallest ingredient comes last. If the first ingredient in a tomato pasta sauce is water, followed by sugar, you are paying for watered-down, sweetened tomatoes. The primary whole food should be at the top of the list.

This list is the only way to identify added sugars. Manufacturers use many different names for sugar. You might see cane sugar, glucose-fructose syrup, maltose, dextrose, agave nectar, rice syrup or fruit juice concentrate. If several of these appear early in the list, the product is heavily sweetened.

Use the ingredients list to check the level of processing. A shorter list of recognisable foods is preferable. Highly processed items often contain many emulsifiers, stabilisers, artificial flavours and preservatives. Choosing foods with simple ingredients supports better nutrition.

When buying grain products like bread or pasta, look for the word “whole” in the first ingredient. Wholewheat flour or whole grain oats indicate the entire grain is used. If the label simply says wheat flour, it is usually refined white flour.

Checking fibre and salt levels

Fibre and salt are two components that frequently get overlooked.

Fibre is a type of carbohydrate that your body cannot digest. It is essential for digestion, bowel regularity and maintaining steady energy levels. Adults should aim for about 30g of fibre a day. Fibre is not always a mandatory item on the UK nutritional grid. When it is listed, look for foods providing at least 3g of fibre per 100g, which are considered a source of fibre. Foods with 6g or more per 100g are high in fibre. Beans, lentils, oats, whole grains, fruits and vegetables are excellent sources.

Salt is listed at the bottom of the grid. Adults should eat no more than 6g of salt a day, which is about one level teaspoon. A food is considered high in salt if it contains more than 1.5g per 100g. It is considered low in salt if it has 0.3g or less per 100g. Pay attention to ready meals, soups, sauces and processed meats, as these are common sources of hidden salt.

Practical steps for the supermarket

Building a habit of reading labels takes practice. You do not need to read every single label every time you shop. Instead, focus on a few key areas to gradually improve your choices.

• Start with packaged staples: Begin by checking the foods you buy every week, such as bread, cereal, milk alternatives or pasta sauces. Once you find a brand with a good nutritional profile, stick with it.
• Compare two items: If you are unsure which product to buy, pick up two similar items and compare their 100g columns. Look at the saturated fat, sugars and salt. Choose the one with the lower numbers.
• Check the first three ingredients: Before putting a packet in your basket, scan the first three items on the ingredients list. Ensure they are foods you recognise.
• Ignore the front packaging: Tune out terms like “lite”, “natural” or “source of protein” printed in large letters. Turn the packet around to verify these claims with the hard numbers on the back.

Taking a systematic approach makes comparing products easier. Over time, you will build a mental database of products that meet your nutritional needs.

When to get it checked

If you have existing health conditions such as type 2 diabetes, high blood pressure, coeliac disease or kidney issues, you must be precise about your food choices. Speak to a GP or a registered dietitian for specific guidance on reading labels to manage these conditions. You should also seek medical advice if you experience severe abdominal pain, persistent bloating, unexplained weight loss, chronic diarrhoea or blood in your stool after eating certain foods. These are red-flag symptoms that require proper investigation. If you are pregnant or taking medications that interact with specific nutrients, a healthcare professional can clarify exactly what you need to look out for on food packaging.