What is the classification of food in science?

January 13, 2026 •

4 min read

Food contains more than 40 different types of nutrients that can be categorized into seven major groups, a primary method for understanding what is the classification of food in science. Scientific classification goes beyond simple food groups, using systems based on chemical composition, physiological function, and degree of industrial processing to define and categorize food items.

Quick Summary

This article explains the different methods used in science to classify food, including categorization by major nutrients (macronutrients and micronutrients), their function in the human body, chemical properties (organic vs. inorganic), and level of industrial processing. The guide details how each system provides a unique lens for understanding food's impact on health and dietary patterns.

Key Points

Nutrient Classification: Food is primarily classified into macronutrients (carbohydrates, proteins, fats, water) and micronutrients (vitamins, minerals) based on their chemical content and the body's need for them.
Functional Classification: Foods are categorized by their role in the body, such as energy-giving (fats, carbs), body-building (proteins), and protective (vitamins, minerals) foods.
Chemical Classification: Based on elemental composition, nutrients are classified as either organic (containing carbon and hydrogen, like fats and carbs) or inorganic (lacking carbon, like minerals and water).
Processing Classification (NOVA): A system that groups food based on its extent of industrial processing, from unprocessed (fresh produce) to ultra-processed (packaged snacks).
Multifaceted Analysis: Multiple classification systems are necessary because no single one can capture all aspects of a food's impact on human health, from its micronutrient content to its processing level.
Public Health Tool: Systems like NOVA are particularly useful for public health officials to study diet-related diseases and formulate policies to improve nutritional outcomes.

Core Scientific Classifications of Food

Food classification in science is not a singular system but a multifaceted approach based on different criteria. Each method offers a unique perspective for understanding food's properties, functions, and overall impact on health. The primary scientific classifications include grouping food by nutritional content, physiological function, chemical properties, and extent of industrial processing. These systems are essential for dietetics, public health policy, and food science research, helping to formulate effective dietary guidelines and monitor consumption trends.

Classification by Nutrient Content

One of the most fundamental ways scientists classify food is by its nutrient composition. Nutrients are the chemical compounds that living organisms need for energy, growth, and cellular function. They are broadly categorized into macronutrients and micronutrients.

Macronutrients: Needed in larger quantities, these are the body's primary fuel source. They include:
- Carbohydrates: Composed of carbon, hydrogen, and oxygen, they are the body's main energy source. Simple carbohydrates (sugars) offer quick energy, while complex carbohydrates (starches and fiber) provide sustained energy.
- Proteins: Polymers of amino acids, proteins are the building blocks for tissues, muscles, and organs. They are crucial for growth and repair.
- Lipids (Fats): A concentrated energy source, fats also aid in vitamin absorption and organ insulation.
- Water: Essential for hydration and most bodily functions, though it does not provide energy.
Micronutrients: Required in smaller amounts, these are vital for metabolic and enzymatic processes. They consist of:
- Vitamins: Organic compounds like Vitamin A, B, C, D, E, and K. They are crucial for everything from vision to immune function.
- Minerals: Inorganic elements like calcium, iron, and potassium, which support bone structure, fluid balance, and nerve transmission.

Classification by Physiological Function

Another scientific approach categorizes food based on its function within the body. This helps people understand what certain foods contribute to their health.

Energy-Giving Foods: These are high in carbohydrates and fats, providing the body with the fuel it needs for daily activities and metabolic processes. Examples include cereals, tubers, and cooking oils.
Body-Building Foods: Rich in proteins, these foods support growth, tissue repair, and the maintenance of a healthy body structure. Meats, eggs, dairy, and legumes are classic examples.
Protective Foods: Primarily composed of vitamins and minerals, these foods help regulate body processes and protect against disease. Fruits and vegetables fall into this category.

Classification by Chemical Properties

Chemically, food can be sorted into organic and inorganic categories based on its elemental composition.

Organic: Nutrients containing both carbon and hydrogen, such as carbohydrates, proteins, lipids, and vitamins. These complex molecules can be broken down or destroyed.
Inorganic: Nutrients that do not contain carbon and hydrogen, such as minerals and water. These are simpler, more stable compounds.

The NOVA Classification of Food Processing

Developed by Brazilian researchers, the NOVA classification system categorizes food by the extent of industrial processing, not just nutrient content. This framework has become a crucial tool in modern public health debates concerning diet-related diseases like obesity.

Group 1: Unprocessed or Minimally Processed Foods: These are foods in their natural state or with minimal alterations that don’t add substances like salt, sugar, or oils. Examples include fresh fruits, vegetables, eggs, and plain milk.
Group 2: Processed Culinary Ingredients: These are substances derived from Group 1 foods used to prepare meals. Think of salts, sugars, and oils.
Group 3: Processed Foods: Made by combining Group 1 foods with Group 2 ingredients, often to improve durability or palatability. Examples include canned vegetables, salted nuts, and simple breads.
Group 4: Ultra-Processed Foods: Industrial formulations made with five or more ingredients, including those not typically used in domestic cooking. These products are often high in added sugar, fat, and salt. Examples include soft drinks, packaged snacks, and instant noodles.

Comparison of Different Food Classification Systems


Classification System	Basis for Grouping	Primary Use	Example Group	Limitations
Nutrient-Based	Chemical compounds like carbohydrates, fats, proteins, vitamins, and minerals.	Dietary recommendations, nutritional research.	Carbohydrates: Grains, potatoes, fruits.	Doesn't account for complex food interactions or processing impact.
Function-Based	Role in the body (energy, building, protection).	Basic nutritional education.	Body-Building Foods: Meats, eggs, dairy.	Oversimplified; many foods serve multiple functions.
NOVA (Processing-Based)	Extent of industrial processing (unprocessed to ultra-processed).	Public health policy, studying diet-related diseases.	Ultra-Processed Foods: Soda, pre-packaged snacks.	Can be complex to apply to certain composite dishes.

Why are Multiple Classifications Necessary?

No single scientific classification system can capture the full complexity of food. Nutritional classification based on macronutrients is excellent for understanding caloric intake and nutrient balance, but it might overlook the health implications of a highly processed product high in sugar. Conversely, the NOVA system is highly effective for public health, as ultra-processed foods are strongly linked to obesity and other chronic diseases, but it does not detail a food's micronutrient profile. Therefore, scientists, dietitians, and consumers use different models to gain a comprehensive understanding, from analyzing the specific vitamins in spinach to evaluating the health risks of a pre-packaged frozen meal.

Conclusion

The scientific classification of food is not a single, rigid system but a collection of methodologies that provide different lenses for viewing our diet. From the foundational nutrient-based model distinguishing between carbohydrates and proteins to the modern NOVA system that scrutinizes the degree of industrial processing, each framework offers valuable insights. By understanding these diverse classifications, both professionals and consumers can make more informed decisions about health and nutrition. For a more detailed dive into food composition and its physiological effects, authoritative sources on nutrition provide a robust knowledge base.

Frequently Asked Questions

Macronutrients are nutrients the body needs in large amounts for energy, such as carbohydrates, proteins, and fats. Micronutrients are vitamins and minerals required in smaller quantities to regulate body functions.

The NOVA system classifies foods into four groups based on how much they have been industrially processed: unprocessed/minimally processed, processed culinary ingredients, processed foods, and ultra-processed foods.

Protective foods are those rich in vitamins and minerals that help regulate body functions and defend against diseases. Examples include most fruits and vegetables.

Food processing significantly alters a food's nutritional profile and links to health outcomes. Classifying by processing helps researchers and public health officials identify connections between diet and chronic diseases like obesity.

Yes, a food can fit into multiple categories across different classification systems. For instance, chicken is a body-building food (function), a protein source (nutrient), and could be considered unprocessed or minimally processed (processing level).

No. In science, organic refers to compounds containing carbon and hydrogen. In a grocery store, 'organic' describes a specific method of farming that avoids synthetic chemicals.

Scientific classification provides the foundational data on nutrient composition, function, and processing effects. This data allows health organizations to create recommendations that promote a balanced intake of macronutrients, micronutrients, and whole foods.