“3 sellos” means a food or drink product in Mexico carries three black octagonal warning seals on its front packaging, each flagging that the product exceeds a safe threshold for a specific nutrient like sugar, sodium, or saturated fat. These seals are part of Mexico’s mandatory front-of-pack labeling system, known as NOM-051, which has required warning labels on packaged foods and non-alcoholic beverages since October 2020.
How the Sello System Works
Mexico’s labeling law requires black octagonal seals (sellos) on any packaged food or drink that contains excessive amounts of five key nutrients: calories, sugars, saturated fats, trans fats, and sodium. Each seal reads “EXCESO” followed by the nutrient in question, such as “EXCESO CALORÍAS” (excess calories) or “EXCESO AZÚCARES” (excess sugars). A product can carry anywhere from zero to five of these seals depending on how many thresholds it exceeds.
When someone says a product has “3 sellos,” they mean it triggers three of those five warnings. A bag of chips might carry seals for excess calories, excess sodium, and excess saturated fat. A sweetened cereal might get flagged for excess calories, excess sugars, and excess sodium. The specific combination varies by product, but three seals generally signals a heavily processed item that’s high in multiple nutrients linked to obesity, diabetes, and heart disease.
What Each Seal Measures
The thresholds that trigger each seal are based on nutrient levels per 100 grams of solid food or 100 milliliters of liquid. Here’s what it takes for a product to earn each warning:
- Excess Calories: Solid foods with 275 or more calories per 100 grams, or beverages with 10 or more calories per 100 milliliters.
- Excess Sugars: Products where 10% or more of total calories come from added sugars.
- Excess Sodium: Solid foods with 300 milligrams or more of sodium per 100 grams. Calorie-free beverages trigger at just 45 milligrams per 100 milliliters.
- Excess Saturated Fats: Products where 10% or more of total calories come from saturated fat.
- Excess Trans Fats: Products where 1% or more of total calories come from trans fats.
These thresholds became stricter in Phase II of the law, which took effect in 2023. A third phase scheduled for 2025 tightens them further, meaning some products that currently show two sellos could soon display three or more unless manufacturers reformulate their recipes.
Additional Warnings Beyond the Octagons
Besides the octagonal sellos, products can also carry rectangular warning labels for caffeine and artificial sweeteners. A product containing caffeine must display “CONTIENE CAFEÍNA EVITAR EN NIÑOS” (contains caffeine, avoid in children). Products with non-nutritive sweeteners must state “CONTIENE EDULCORANTES, NO RECOMENDABLE EN NIÑOS” (contains sweeteners, not recommended for children). These rectangular labels sit above the octagonal seals on the upper right corner of the package. They aren’t counted among the sellos, so a product described as having “3 sellos” could also carry one or both of these additional warnings.
Why the Labels Exist
Mexico adopted this system to address one of the highest rates of obesity and diabetes in the world. The country modeled its approach on Chile, which pioneered a similar black-octagon system in 2016. Chile’s labels use the phrase “Alto en” (high in), while Mexico’s use “Exceso” (excess), a deliberate word choice intended to convey stronger urgency.
Both countries rolled out their systems in three phases, gradually tightening the nutrient thresholds so manufacturers had time to reformulate. The phased approach has worked to some degree: many producers have reduced sugar, sodium, and fat in their products specifically to shed one or more sellos from their packaging. From the consumer side, surveys show the labels influence purchasing decisions. A 2021 study of more than 3,300 Mexican Americans shopping at Mexican-oriented stores in the United States found that nearly two-thirds noticed the warning labels, and many reported buying less of a range of unhealthy foods because of them.
How to Use the Sellos When Shopping
The sellos work as a quick visual shorthand. Zero sellos means the product falls below all five warning thresholds. One or two sellos suggests moderate concern in specific areas. Three or more sellos indicates a product that exceeds safe limits across multiple nutrients, making it one of the least nutritious options in its category.
If you’re comparing two similar products, say two brands of yogurt, the one with fewer sellos has lower levels of the nutrients most strongly linked to chronic disease. That said, the sellos don’t capture everything about a food’s nutritional value. They don’t account for fiber, protein, vitamins, or minerals. A handful of nuts might carry a seal for excess calories while still being a nutrient-dense choice. The system is designed to flag risk rather than provide a complete nutritional picture, so it works best as a first filter rather than a final verdict.
Products with three or more sellos also face additional restrictions in Mexico. They cannot use cartoon characters, celebrity endorsements, or other marketing strategies aimed at children on their packaging. This is why you’ll notice that many heavily processed snacks and sugary cereals sold in Mexico look visually different from their versions in the United States or other countries.