How to understand food labels?

Food labels can be an excellent tool to make informed decisions when buying foods; however, despite the efforts and regulations, food labels can be unintuitive and difficult to understand (1,2). 

In this brief guide, we will address the query “How to understand food labels?” We will explore relevant information regarding food labels, such as health claims, nutrition facts and serving calculation, as well as identifying the ingredients in foods.

How to understand food labels?

To understand food labels you should know what are the key components of food labels; the most important components of food labels are (1,2): 

  • Label claims: useful to identify valuable information about processing and quality certifications, or health-related attributes (i.e.: high in fiber).
  • Nutritional information (or Nutrition Facts): the nutrition facts are important to inform you how many nutrients you are eating.
  • List of ingredients: helpful to identify ingredients, especially when looking for potentially harmful (allergens) or undesired ingredients (i.e.: artificial colorants)
  • Date labels: explains the recommended dates for consuming the product.

Even though there are international organizations like the Food and Drug Administration, for instance, that standardize the information required in food labels, this information could be difficult to interpret (2).

In the rest of this article, we will briefly explore how to interpret the food label components.

What are food labels, and why are they important?

Food labeling is a regulation technique to support consumers to make better and healthier decisions on food choices, ensures transparency, and helps for food safety (1,2). 

The importance of food labels rely on the needs of transparency about composition, whether to avoid allergens, to adhere to a certain diet (i.e.: low-sugar diet) or cultural ideologies (such as Halal certification) (1,2).

Another essential use of food labels is traceability (food monitoring along the supply chain), which is used (mainly) in terms of logistics efficiency for enterprises and safety for consumers (1,2). 

What are label claims?

Label claims present information related to the product processing or certifications, for example, gluten-free, organic, GMO-free, among others. On the other hand, label claims can direct towards health-related purposes, like sugar-free or high-fiber (1).

Normally, label claims are at the front of the package, and can be accompanied by logos or images in the case of certification claims (1).

Recently, health-related claims inform about health-risks rather than health-benefits; this strategy was implemented to increase the awareness about excessive intakes (1). 

For example, Multiple Traffic Lights food labels use red, yellow, and green colors to advise consumers if the product is high on a specific nutrient; in this case, red means high content, yellow a medium content, and green a low content (1).

You can use this illustration to choose healthier foods, for instance:

  • Select food products with green-colored sugar claims (low sugar content) if you must avoid sugar in your diet.
  • Avoid those products with red-colored salt claims if your doctor advised you to reduce sodium intake.
  • If you are on a low-fat diet, maybe you should stick to food products with green-colored fat claims.

Take into account that every country has its own label regulations, and not everyone uses Multiple Traffic Lights food labels. However, there are other intuitive label formats like warning labels indicating high content of an ingredient, or the Health Star Rating which specify if an ingredient is in low, mid, or high concentration (1).

There are also less intuitive label claims, such as the Guideline Daily Amounts labels. Guideline Daily Amounts label presents a percentage of the nutrient intake per portion of the product, based on a 2000 calorie diet for healthy people (1).

How to understand Nutrition facts?

Nutrition facts are at the back of the package, it provides details of all nutritional composition of the product. Nutritional composition includes energy, fats, carbohydrates, proteins, and fiber; you can also find vitamins and minerals content in the product (1,2).

Usually, nutrition facts are calculated for a portion of the product, so you have to take into account the following (1,2):

  • Check at the serving size indicated in the nutrition facts, it could range from a few grams (for example: 25 g) to 100 g.
  • Then look at how many servings the product has; if not given, divide the total weight of the product by the serving size. For instance, if there are 200 g in the whole product and 1 serving is 50 g, divide 200 by 50, and you will have the number of servings (4 servings).
  • Then, you can multiply the amount of the nutrients times the number of servings in the package to know the nutritional composition of the whole product.

It is important to calculate the whole nutritional composition of the product, because it is common to only report the nutritional composition per serving. Therefore, if you eat the whole package, maybe you are eating more calories, fats, or carbs than you think (1,2).

For example, the following table mimics a food label nutrition fact. As you can see, it can be very different from eating 1 serving than eating the whole package.

Serving size50 g
Servings per package4
Content in 1 servingContent in whole product
Total Fat8 g32 g
Total Carbohydrates37 g148 g
Proteins3 g12 g

Adapted from: Food and Drug Administration (3)

How to interpret the ingredients list?

You will find the ingredient list at the back of the package, it informs you of all ingredients used in the product, including ingredients like cereal flours, fruit, water, and sugars, and additives like colorants, flavors, stabilizers, among others (2). 

The ingredient list is ordered by quantity used; in this sense, the most abundant ingredient will be placed in the first position, and the less abundant ingredient will be placed last (2).

Usually, allergens like nuts, peanuts, milk derivatives, soy derivatives, egg protein, and shellfish are highlighted in bold font. Thus, consumers can be aware and avoid this product if they have an allergy to some of these ingredients (2).

Otherwise, at the end of the ingredients list is a short claim that explicitly states the allergens present in the product (2).

How to interpret date labels?

The date labels are provided to inform the dates of the best quality of the product. There are three types of dates (4):

  • Sell-by: it is the limit date for a store to display this product for sale.
  • Use-by or Best-use-by: the limit date recommended for using the product at its best quality. It is not explicitly a safety date, it refers to quality parameters like texture, appearance, and taste. However, it is a safety date for infant products.


In this brief guide, we addressed the query “How to understand food labels?” We explored relevant information regarding food labels, such as health claims, nutrition facts and serving calculation, as well as identifying the ingredients in foods.


  1. Temple NJ. Front-of-package food labels: A narrative review. Appetite, 2020;144(104485):104485.
  1. Temple NJ, Fraser J. Food labels: a critical assessment. Nutrition, 2014;30(3):257–60.
  1. Changes to the Nutrition Facts label [Internet]. U.S. Food and Drug Administration. FDA; [cited 31 May 2023]. Available from:
  1. Food Product Dating. [cited 31 May 2023]. Available from:,product%20while%20at%20peak%20quality.