Understanding How Is Junk Food Classified?

November 6, 2025 •

3 min read

According to a 2023 World Health Organization (WHO) report, unhealthy diets are a major cause of chronic diseases and high mortality rates in some regions. A critical step toward mitigating these risks is understanding how is junk food classified, which helps consumers identify and limit high-fat, high-sugar, and high-salt (HFSS) products.

Quick Summary

Junk food classification depends on several factors, including its nutritional density, level of industrial processing, and ingredient composition. While no single, universally agreed-upon definition exists, different systems like nutrient profiling and the NOVA classification help consumers identify foods that offer high calories with minimal nutritional benefit.

Key Points

Nutritional Profile: Junk food is primarily defined by its high calorie count and low nutritional content, often termed 'empty calories'.
HFSS Classification: Criteria like High in Fat, Salt, and Sugar (HFSS) are used by regulatory bodies to identify and regulate unhealthy foods.
Processing Level (NOVA): The NOVA system classifies food based on industrial processing, with most junk food falling into the ultra-processed category (Category 4).
Addictive Properties: The specific blend of sugar, salt, and fat in junk food is engineered for high palatability, which can encourage overconsumption.
Health Consequences: Frequent consumption of junk food is associated with health problems like obesity, type 2 diabetes, and cardiovascular disease.
Informed Choices: Knowing classification systems helps consumers make better food decisions by assessing composition and processing.

What Exactly Is 'Junk Food'?

The term “junk food” became popular in the 1970s to describe foods high in calories but low in nutritional value. While the definition can be subjective, it generally refers to foods designed for palatability through a specific balance of salt, sugar, and fat. This can lead to overconsumption by overriding natural satiety signals.

The 'Empty Calories' Concept

A key aspect of classifying junk food is the concept of "empty calories". These foods provide energy without significant amounts of protein, vitamins, minerals, or fiber. Consuming empty calories can displace more nutrient-dense foods, potentially leading to deficiencies. Examples include candy, sugary drinks, and salty snacks, often high in refined sugars and unhealthy fats.

Classification by Nutritional Profile (HFSS)

Many health authorities classify junk food based on its nutritional makeup. The High in Fat, Salt, and Sugar (HFSS) criteria, used by regulatory bodies, evaluate nutrient content to define products high in saturated fat, excessive salt, and high amounts of free or added sugar. This provides a quantifiable way to assess a food's healthiness and inform public health policies.

Classification by Processing Level (NOVA System)

The NOVA system, developed in Brazil, classifies foods based on their degree and purpose of industrial processing. It has four categories:

Category 1: Unprocessed or minimally processed foods (e.g., fruits, vegetables).
Category 2: Processed culinary ingredients (e.g., salt, oil).
Category 3: Processed foods (e.g., canned vegetables).
Category 4: Ultra-processed foods (industrial formulations with many ingredients, including additives).

Most junk food falls into Category 4. These foods are designed to be hyper-palatable, convenient, and often lose natural nutrients during processing. High consumption of ultra-processed foods is linked to increased risks of chronic diseases.

The Spectrum of Junk Food and Examples

Junk food includes various calorie-dense items with low nutritional value. Examples often include fast food, sugary drinks, salty snacks, sweets, processed meats, and some breakfast cereals.

Comparison Table: Junk Food vs. Whole Foods

A comparison between junk food and whole foods highlights key differences:


Feature	Junk Food (Example: Fast Food Burger)	Whole Food (Example: Homemade Burger)
Nutrient Profile	Typically low in fiber, vitamins, and minerals; often high in unhealthy fats, sugar, and sodium.	Generally rich in fiber, vitamins, minerals, and healthy fats from fresh, unprocessed ingredients.
Processing Level	Often ultra-processed with many additives for preservation and flavor.	Minimally processed, using simple ingredients.
Calorie Density	High calorie-per-volume, potentially leading to overconsumption.	More balanced calorie-per-volume, supporting satiety.
Ingredients	May contain refined grains, preservatives, artificial flavorings, and unhealthy oils.	Typically includes whole grains, fresh produce, lean protein, and healthy oils.
Health Impact	Linked to obesity, diabetes, and cardiovascular issues.	Supports overall health and weight management.

Conclusion: Navigating Your Diet with Knowledge

Understanding how is junk food classified allows for informed dietary choices. By utilizing tools like nutrient profiling and the NOVA system, you can assess foods based on their composition and processing. While moderate consumption is acceptable, a diet dominated by ultra-processed, calorie-dense foods carries significant health risks. Focusing on whole, minimally processed foods supports overall well-being. Being aware of processing levels can help improve nutritional habits. For detailed healthy eating advice, consult national dietary guidelines.

Frequently Asked Questions

The simplest way is to look for foods high in calories from fat and sugar but low in essential nutrients like vitamins, minerals, protein, and fiber. These are frequently packaged and highly processed.

While many fast-food items, particularly fried ones, qualify as junk food, some options like salads can be more nutritious depending on ingredients and preparation.

The NOVA system classifies foods into four groups based on the level of industrial processing, from unprocessed (Group 1) to ultra-processed (Group 4).

Junk food is crafted to reach a 'bliss point,' a specific combination of sugar, fat, and salt designed to be very tasty and promote overeating.

Yes, some processed foods can be healthy. Minimally processed items like canned vegetables or basic bread are healthier than ultra-processed junk food, which involves extensive industrial steps.

Regular junk food intake is commonly linked to obesity, type 2 diabetes, cardiovascular disease, digestive problems, and poor bone health.

Begin by identifying junk foods in your diet, prioritizing whole, unprocessed options, preparing meals ahead of time, and reading labels to avoid items high in added sugar, salt, and fat.

'Empty calories' refers to foods and drinks that provide substantial energy (calories) but offer minimal or no essential nutrients like protein, vitamins, minerals, and fiber.