What are Processed Foods? A Comprehensive Guide

In today's modern food landscape, processed foods have become an integral part of many people's dietary habits. Studies show that ultra-processed foods make up nearly 60% of the average American diet, highlighting their widespread consumption. From convenience and affordability to extended shelf life, these foods play a significant role in how we eat. However, understanding what constitutes processed food, its various classifications, and its impact on health is crucial for making informed dietary choices. While some processed foods can be part of a balanced diet, others may contain additives, preservatives, and high levels of sugar, salt, or unhealthy fats that raise health concerns.

What are processed foods?

Processed foods are any foods that have been altered from their natural state for reasons like:

• Safety (e.g., pasteurizing milk to kill harmful bacteria)

• Preservation (e.g., freezing fruits to extend shelf life)

• Convenience (e.g., pre-cut vegetables for quick meal prep)

Food processing exists on a spectrum, ranging from minimally processed to ultra-processed foods. To better understand these differences, dietitians and health professionals use the NOVA classification system, which categorizes foods based on the degree and purpose of processing.

Categories of food processing

The NOVA Classification System divides foods into four main categories:

1. Unprocessed or minimally processed

2. Processed culinary ingredients

3. Processed foods

4. Ultra-processed foods

The table below provides clear examples of common foods across different levels of processing.

Source: Harvard Health Publishing

Minimally processed foods

These whole foods undergo basic processing while maintaining their nutritional value and natural structure. Examples include: 

• Fresh fruit

• Pasteurized milk

• Frozen vegetables

• Dried legumes

• Plain yogurt

• Whole grains

These foods are typically part of a healthy diet and retain most of their inherent nutritional benefits.

Processed culinary ingredients

These are ingredients extracted and purified from whole foods, used primarily for cooking and food preparation. Examples include: 

• Nut or seed oils 

• Butter, lard, or coconut fat

• Honey 

• Maple syrup 

• Beets or cane sugar

• Sea salt

Processed foods

These foods are made by combining whole foods with culinary ingredients like salt, sugar, or oil. Examples include: 

• Canned legumes or vegetables, preserved in salt, vinegar, or by pickling

• Freshly-made (unpackaged) breads made of wheat flour, yeast, water, and salt 

• Beef jerky or bacon

• Tomato extract, pastes, or concentrates (with salt and/or sugar)

• Freshly-made cheeses

• Fermented alcoholic beverages such as beer, alcoholic cider, and wine

While they may contain added ingredients, they generally retain much of their basic nutritional integrity.

Ultra-processed foods

Ultra-processed foods are the most heavily modified, often containing a combination of additives, preservatives, emulsifiers, and artificial colors to enhance flavor, texture, and shelf life. These foods typically include:

• Five or more ingredients, many of which are industrially formulated rather than whole-food based.

• Added sugar, salt, oils, fats, stabilizers, and preservatives to improve taste and longevity.

• Additives that imitate the flavor, color, or texture of less processed foods.

• Ingredients not found in nature, such as high fructose corn syrup and artificial flavorings.

Common examples of ultra-processed foods include:

• Soft drinks 

• Potato chips 

• Hot dogs and pre-prepared (packaged) meats, fish, and vegetables

• Ice creams and frozen desserts

• Many breakfast cereals and bars 

• Packaged microwave meals 

• Distilled alcoholic beverages (e.g., whisky, gin, rum, vodka)

These foods are often low in nutritional value and can contribute to health issues when consumed in excess. Understanding ingredient lists and nutrition labels can help make more informed dietary choices.

The impact of food processing on nutrition

Nutritional changes

Processing can significantly affect a food's nutritional value. While some processes like fortification may add nutrients such as calcium or vitamin D, others can strip away beneficial components. The U.S. Food and Drug Administration (FDA) regulates what goes on the Nutrition Facts label, revealing how processing has modified the food's natural nutritional profile.

Added ingredients

Processed foods often contain various additives for different purposes:

• Preservatives extend shelf life

• Emulsifiers improve texture

• Artificial colors enhance appearance

• Sweeteners, including high-fructose corn syrup, add flavor

• Hydrogenated oils improve stability but may contain harmful trans fats

Health implications of processed foods

Potential health risks

The long-term health risks of ultra-processed foods are becoming increasingly evident. Dr. Stephen Devries, a preventive cardiologist and executive director of the Gaples Institute in Chicago, emphasized the serious consequences of consuming these foods. “Health consequences of ultraprocessed foods are dire. A large study conducted over 19 years showed a 31% higher mortality for the highest versus lowest consumers of ultraprocessed foods. The concerns include recent documentation of an increased risk of type 2 diabetes, cardiovascular disease and dementia.”

The findings from this study, along with mounting research, reinforce the strong link between ultra-processed food consumption and chronic diseases, emphasizing the importance of making informed dietary choices. Several key risks include:

Obesity and weight gain

In a 2019 study published in Cell Metabolism, participants who followed an ultra-processed diet consumed 500 more calories per day and gained weight compared to those eating a minimally processed diet — even when both diets contained the same macronutrient balance. This aligns with extensive research linking ultra-processed foods to higher rates of obesity. These foods tend to be: 

• High in calories, sugar, and unhealthy fats

• Offer less dietary fiber 

• Contain fewer essential nutrients compared to whole foods

Increased risk of chronic diseases

Diets high in processed foods have been associated with a greater likelihood of developing:

• Heart disease: Due to excessive sodium, trans fats, and refined sugars.

• Type 2 diabetes: Linked to high glycemic loads and frequent consumption of refined carbohydrates.

• High blood pressure: Often caused by excessive sodium intake from processed foods.

Health concerns from processed meats

Processed meats — such as bacon, sausages, and deli meats — contain nitrates and nitrites, which have been linked to:

• Elevated cholesterol levels 

• Cardiovascular issues 

• Regular consumption has also been associated with an increased risk of certain cancers.

Reading food labels

Understanding ingredient lists and food labels is crucial for making informed dietary choices. Ingredients are listed by weight, with the most prevalent ingredients first. Long lists of unfamiliar ingredients often indicate highly processed foods.

Making healthier choices

Smart shopping strategies

Imagine you're grocery shopping for a quick breakfast option. Instead of grabbing a sugary granola bar, you could pick up plain Greek yogurt, fresh berries, and a handful of nuts for a protein-rich, fiber-packed meal. Likewise, choosing whole wheat pasta with homemade tomato sauce instead of boxed mac and cheese is a simple switch that reduces added preservatives while keeping convenience.

Navigating the grocery store with awareness and planning can help reduce processed food intake. While the store perimeter often contains more whole, less processed foods, there are also nutrient-dense options in the middle aisles if you know what to look for.

Shop the perimeter for:

• Fresh fruits and vegetables

• Minimally processed proteins (e.g., fresh meat, poultry, seafood, tofu)

• Dairy products like plain yogurt and cheese

• Whole grain bread and bakery items with minimal additives

Find healthy staples in the aisles:

• Canned and frozen foods: Look for low-sodium canned beans, tomatoes, and frozen fruits/vegetables with no added sauces.

• Whole grains: Brown rice, quinoa, whole wheat pasta, and oats.

• Nuts, seeds, and dried fruit: Choose unsalted and unsweetened varieties.

• Legumes: Canned (low-sodium) or dried beans, peas, and lentils for a protein-rich option.

• Healthy fats: Extra virgin olive oil, avocado oil, and nut butters with minimal ingredients.

Healthy alternatives

Making small, intentional swaps can significantly improve dietary quality:

• Instead of processed breakfast cereals → Choose whole-grain oatmeal with fresh fruit.

• Instead of deli meats → Opt for home-cooked lean proteins like grilled chicken or turkey.

• Instead of refined white bread → Go for whole grain or sprouted grain options.

• Instead of sugary flavored yogurts → Choose plain yogurt with honey or fruit.

• Instead of store-bought salad dressings → Make your own with olive oil, lemon, and herbs.

For example, if you’re craving a fast-food breakfast sandwich, try making a healthier version at home:

• Fast food version: A McDonald's Sausage & Egg McMuffin contains 423 calories, 23g fat, and 1800mg sodium.

• Homemade version: A whole wheat English muffin with scrambled eggs, avocado, and lean turkey sausage delivers fewer processed additives, more fiber, and more than half the sodium — all in under 10 minutes.

Practical tips for reducing processed food intake

Eliminating processed foods entirely may not be realistic, but minor, intentional adjustments can lead to significant improvements in overall dietary quality. Focus on:

1. Small changes: Completely eliminating processed foods may not be practical, but small improvements can make a big difference.

2. Read ingredient labels: Look for shorter ingredient lists with recognizable, whole-food components.

3. Cook more at home: Preparing meals from scratch reduces reliance on highly processed convenience foods.

4. Stay mindful of packaging claims: "Low-fat" or "sugar-free" doesn’t always mean healthier, so be sure to check for added preservatives and artificial ingredients.

For example, when selecting peanut butter, compare the ingredients:

Minimally processed option: Peanuts, salt.

Ultra-processed option: Peanuts, sugar, hydrogenated vegetable oils, salt, mono- and diglycerides.

Even a simple swap like choosing natural peanut butter over processed peanut butter can reduce unhealthy additives in your diet. Instead of aiming for perfection, focus on these sustainable transitions and mindful choices that fit your lifestyle. 

Frequently Asked Questions

What defines a food as being processed?

A food is considered processed when it has been altered from its natural state for safety or convenience. The NOVA classification system defines processing levels from unprocessed or minimally processed (like cleaned and packaged fruits) to ultra-processed (like packaged snacks with numerous additives).

How are processed foods different from whole foods?

Whole foods exist in their natural state or with minimal alterations. They typically contain no added ingredients and maintain their original nutritional profile. Processed foods have been modified from their natural state and often contain additional ingredients for preservation, flavor, or texture enhancement.

What are the differences between processed and unprocessed foods?

Unprocessed foods are whole foods in their natural state, like fresh fruit, vegetables, and legumes. Processed foods have undergone modification and typically contain added ingredients. The key differences lie in:

• Ingredient composition: Unprocessed foods contain no added ingredients, while processed foods often include preservatives, flavorings, or refined components.

• Nutritional content: Whole foods retain their natural nutrients, whereas processed foods may have added sugars, sodium, or unhealthy fats.

• Shelf life: Unprocessed foods spoil faster, while processed foods have a longer shelf life due to preservatives and packaging.

• Convenience: Processed foods are often ready-to-eat or require minimal preparation, while whole foods may need washing, cutting, or cooking.

• Cost: Processed foods can be more affordable and accessible, but unprocessed foods generally offer better long-term health benefits.

What are examples of processed foods?

Common processed foods include breakfast cereals, canned soups, deli meat, pasteurized milk, wheat bread, and frozen meals. The degree of processing varies significantly among these products, with some being minimally processed and others heavily modified.

What are the most processed foods to avoid?

The foods that typically warrant the most concern include:

• Sugar-sweetened beverages and soft drinks

• Packaged snacks and potato chips

• Processed meats like hot dogs and some deli meats

• Pre-made desserts and ice cream with numerous additives

• Instant noodles and soups with high sodium content

What do food additives do?

Food additives serve various functions in processed foods:

• Preservatives prevent spoilage and extend shelf life

• Emulsifiers maintain consistent texture

• Artificial colors enhance visual appeal

• Flavor enhancers intensify taste

• Stabilizers maintain product structure

Why are processed foods considered unhealthy?

Processed foods, particularly ultra-processed foods, often contain:

• Added sugars and sodium: Contribute to weight gain, high blood pressure, and other health issues.

• Unhealthy fats: Often include trans fats, which raise bad cholesterol and increase heart disease risk.

• Artificial additives and preservatives: Used to enhance flavor and shelf life but may have negative health effects.

• Lower fiber and nutrients: Less dietary fiber and essential vitamins compared to whole foods.

• High calorie, low nutrition: More calories with fewer beneficial nutrients, leading to poor diet quality.

The bottom line

While processed foods are a convenient part of modern diets, understanding their impact on health is essential for making informed choices. By focusing on whole and minimally processed foods, reading ingredient labels, and making small, mindful swaps, individuals can improve their overall dietary quality. Completely eliminating processed foods may not be practical, but prioritizing nutrient-dense options can lead to long-term health benefits. With awareness and balance, it’s possible to enjoy the convenience of processed foods while maintaining a healthier lifestyle.