Why do food labels have a per 100g column? An Essential Guide to Smarter Choices

December 2, 2025 •

4 min read

Food labelling can be confusing for over 60% of consumers. However, the 'per 100g' column exists for a crucial reason: it provides a standardized reference unit to accurately compare the nutritional content of different food products, irrespective of arbitrary serving sizes. This column is a powerful tool for making educated decisions at the grocery store.

Quick Summary

The 'per 100g' column on food labels is a standardized unit for comparing nutritional content across similar products, bypassing potentially misleading 'per serving' values. This uniformity enables consumers to identify healthier options easily, particularly when comparing fat, sugar, and salt levels.

Key Points

Standardized Comparison: The "per 100g" column provides a consistent, standardized reference unit for accurately comparing the nutritional content of different food products and brands.
Bypassing Misleading Serving Sizes: It overcomes the unreliability of 'per serving' information, which can vary significantly between manufacturers, allowing for a true like-for-like nutritional evaluation.
Identifying Healthier Options: Use the column to quickly and easily identify products that are genuinely lower in saturated fat, total sugars, and sodium.
Mandatory in Many Regions: In many parts of the world, including the EU and UK, providing 'per 100g' nutritional values is a mandatory legal requirement for prepackaged foods, ensuring consistent information.
Assists with Portion Control and Cooking: The column simplifies calculating the precise nutritional value of specific portion sizes for custom meal preparation and dietary management.
Reveals True Nutritional Density: It shows the true nutrient density of a product, preventing consumers from being deceived by a low 'per serving' value on high-calorie or high-sugar items.

The Core Purpose of the 'Per 100g' Column

At its heart, the primary purpose of the 'per 100g' or 'per 100ml' column is to provide a universal baseline for comparison. Food manufacturers often determine their own 'per serving' sizes, which can vary wildly and make it difficult to compare products directly. A serving of one brand of muesli might be 30g, while another might list a serving as 50g. This difference makes a direct nutritional comparison based on the 'per serving' column misleading. The 'per 100g' standard removes this inconsistency, allowing for a true apples-to-apples comparison of nutrient density.

Why 'Per Serving' Can Be Misleading

The 'per serving' metric, while useful for understanding the nutritional load of a typical portion, is not a reliable metric for direct brand-to-brand comparison. For example, a manufacturer might set a small serving size to make a high-sugar food appear healthier. As one source points out, some confectionery brands use low serving sizes to make their products seem less calorific. The 'per 100g' column cuts through this marketing-driven variability, providing a consistent metric that reveals the true nutritional composition of the food.

Using the 'Per 100g' Column to Make Healthier Choices

Savvy consumers use the 'per 100g' column to scrutinize key nutritional components. For those aiming to reduce their intake of saturated fat, sugar, or sodium, this column is invaluable.

Here is a list of how to use the 'per 100g' column for specific nutritional goals:

Comparing Saturated Fat: Check the 'Saturated Fat' row in the 'per 100g' column. Choosing the product with the lower figure helps reduce the intake of unhealthy fats. For dairy, a good benchmark is less than 2g per 100g.
Monitoring Sugar Intake: The 'Sugars' row shows the total amount of both added and naturally occurring sugars per 100g. A lower number indicates a better choice for controlling sugar consumption. A value under 5g per 100g is generally considered low.
Limiting Sodium (Salt): High sodium intake is a risk factor for heart disease. Use the 'per 100g' column to select the product with the lowest sodium content. Less than 120mg per 100g is considered low sodium.
Boosting Fibre: For fibre, look for a higher number in the 'per 100g' column. Fibre is beneficial for digestive health and is often listed voluntarily by manufacturers.

Legal and Regulatory Requirements

Across many parts of the world, including the European Union and the UK, providing 'per 100g' nutritional information is a mandatory legal requirement for most prepackaged foods. The European Food Information to Consumers (FIC) Regulation (EU) No 1169/2011 mandates that a nutritional declaration must be displayed, including values for energy, fat, saturates, carbohydrates, sugars, protein, and salt, with all values provided per 100g or 100ml. Other countries, such as Australia and New Zealand, also incorporate this standard to empower consumers. This legal backing ensures the reliability and consistency of the information provided on food labels.

Comparison Table: Cereal A vs. Cereal B

To illustrate the value of the 'per 100g' column, consider a comparison of two hypothetical brands of children's breakfast cereal.


Nutrient	Cereal A (per 50g serving)	Cereal A (per 100g)	Cereal B (per 30g serving)	Cereal B (per 100g)
Energy	200 kcal	400 kcal	135 kcal	450 kcal
Fat	2g	4g	1.5g	5g
Saturates	0.5g	1g	0.3g	1g
Sugars	10g	20g	5g	16.7g
Salt	0.25g	0.5g	0.15g	0.5g

At first glance, a shopper might assume Cereal B is the healthier option because its 'per serving' values for sugar (5g) and fat (1.5g) are lower than Cereal A's. However, by looking at the 'per 100g' column, it becomes clear that Cereal B is actually more calorific, has a higher fat content, and is only marginally lower in sugar when compared on a standardized basis.

The Role of 'Per 100g' for Portion Control and Cooking

Beyond simple comparisons, the 'per 100g' column is essential for those who need precise control over their dietary intake, such as people on a weight management or medical diet. If you are baking a cake with a particular flour and want to know the exact carbohydrate content of your portion, you can use the 'per 100g' value to calculate it precisely, regardless of the manufacturer's suggested serving size. This provides flexibility and control for cooking and meal planning.

Conclusion

Understanding why do food labels have a per 100g column? is a key step towards becoming a more informed and health-conscious consumer. The column provides a clear, standardized, and legally-backed metric that removes the guesswork from comparing products with varying serving sizes. By actively using this information, shoppers can make smarter, healthier choices for themselves and their families, ensuring they are not misled by clever marketing on the front of the pack. It's a simple change in habit that offers significant benefits for nutritional awareness.

For more information on food labelling in the UK, consult the official guidance provided by the Food Standards Agency.

Frequently Asked Questions

The 'per serving' size is determined by the manufacturer and can differ greatly between brands, even for similar products. This makes direct comparison unreliable. The 'per 100g' column provides a consistent reference unit, ensuring an accurate, objective comparison.

While its use is widespread for consumer clarity, mandatory regulations vary by region. It is a legal requirement in many places, including the European Union and the UK, as mandated by the FIC Regulation. The US primarily focuses on 'per serving' but 'per 100g' may be included.

Labels for solid foods show values per 100g, while liquid foods show them per 100ml. You can compare products within the same category (e.g., one liquid with another) using the same 100ml standard. For instance, compare different fruit juices based on their 'per 100ml' sugar content.

Not necessarily. While lower total fat can be good for weight management, some fats, like unsaturated fats, are healthy. It is more important to focus on minimizing saturated and trans fats, which are also listed in the 'per 100g' breakdown.

By using the standardized 'per 100g' column, you can easily compare the calorie and fat density of similar products. This allows you to choose lower-energy options, which helps manage your overall calorie intake for weight control.

The ingredients list, which orders ingredients by weight, is crucial for context. It can reveal if the product is primarily composed of less healthy ingredients like sugar or saturated fat. The list helps identify hidden ingredients that may not be apparent from the numerical values alone.

Yes. The 'per 100g' value is perfect for this. If you are eating a 75g portion of a product, you can calculate the nutritional intake by multiplying the 'per 100g' values by 0.75. This is useful for cooking or portioning accurately.