Over the past century, our food system has undergone a fundamental transformation. The evolution from whole foods, sourced mainly from plants or animals, to extracted ingredients, processed foods, and branded products containing food fractions, modified nutrients, various additives, and non-food substances [known as ultra-processed foods] has significantly impacted our dietary landscape.
Modern Dietary Environment
In less than three generations, our food system has shifted from fresh, home-prepared meals to fast food, convenience products, and ultra-processed foods, enhancing the pleasure of daily dining and social interactions. A diverse array of food options provides choices, increasing the convenience of pre-packaged or takeout meals readily available at any time.
This shift enables individuals, single parents, or dual-income families to lead busy lives of their choosing without being constrained by the time-consuming tasks of growing, shopping for, and preparing food.
The changes in our food system have a noticeable effect on the types of foods we consume, contributing to the rising prevalence of global food-related diseases. Surprisingly, the role of processing, the varying impact of food processing levels, and the changes in our food system have only been marginally considered in some dietary guidelines and authoritative sources over the past decade.
The challenge lies in the fact that, for the past century, nutritional science has primarily focused on nutrients or food groups based on nutrient composition. The effects of processing have largely been overlooked, except for specific foods such as processed meats or those containing trans fats.
Categorizing Food by Nutrients or Food Groups
Historically, nutritionists categorized food based on nutrients. National dietary guidelines emphasize healthy food groups [fruits, vegetables, legumes, grains, dairy, eggs, meats, poultry, fish, seafood, nuts, and seeds], with the underlying concept that these foods are nutrient-rich. Consuming a variety of foods from these groups provides balanced nutrition.
Additionally, it is well-known that certain nutrients (saturated fats, salt, and added sugars) should be limited in intake.
Recently, specific dietary patterns [e.g., DASH diet, Mediterranean diet, or foods within the Healthy Eating Index] have been promoted as “healthy,” while others [such as the “Western” dietary pattern] are deemed “less healthy.”
Categorizing Food by Processing Levels
Until recently, little attention has been given to the impact of food processing, especially ultra-processed foods, and the economic factors driving the food supply. However, most foods available in supermarkets and consumed today are highly processed.
The NOVA classification categorizes foods based on processing levels. Click here to see the NOVA food classification in chart form.
- Group 1: Unprocessed and minimally processed foods.
- Group 2: Processed cooking ingredients [e.g., fats, oils, added sugars, and salt].
- Group 3: Traditional foods processed from Groups 1 and 2 [e.g., artisanal bread, pickled vegetables, syrup-soaked fruits, and some cheeses].
- Group 4: Formulations created through industrial processes, primarily using specialized ingredients, including proteins, hydrogenated oils, modified starches, and sugars; marketed as replacements for other food groups.
Understanding Ultra-Processed Foods
Ultra-processed foods, as defined in the NOVA food classification, are products prepared solely in laboratories or food factories using industrial formulations. They consist of processed food ingredients or synthesized from food matrices or other organic sources in a laboratory. These may include hydrogenated fats, modified starches, colorings, preservatives, flavorings, enhancers, and other additives. Examples encompass snacks, candies, energy drinks, soft drinks, cereal bars, cake mixes, sweetened yogurts, ice cream, instant noodles, condiments, sauces, pre-packaged meats, hot dogs, burgers, pizzas, instant soups, fish and chicken nuggets, commercial baked goods, and fried snacks.
Ultra-processed foods are delicious, calorie-dense, affordable, and increasingly prevalent in the form of fast food, takeout, convenience items, candies, and snacks. They are available in supermarkets, convenience stores, gas stations, and vending machines. Marketing is predominantly through direct advertising and may extend to sponsorships of sports events and charity activities.
Celebrations often revolve around the consumption of ultra-processed foods, marked by events throughout the calendar year (Halloween, Easter, Christmas, sports events, charity activities, birthdays, and workplace gatherings). While people have always celebrated with food, the experience has evolved.
Effects of Ultra-Processed Foods
Evidence suggests a correlation between high consumption of ultra-processed foods and adverse health effects. Ranking the healthiness of foods based on their processing effects, it is beneficial to primarily consume a whole-foods diet and avoid or limit ultra-processed foods.
Higher Energy Density: Products refined, extracted, and concentrated through food processing have a higher calorie-to-calorie and energy density than the original foods, regardless of their source. Thus, potato chips, cereal bars made from grains, sausages made from beef, and processed cheeses made from milk all yield products with higher energy density than the original foods.
Convenience of Ultra-Processed Foods: The permeation of food and recipe convenience makes it challenging for people to make healthy food choices. Over the past six decades, food has shifted from being nutrition-centric to convenience-centric, fundamentally altering the food environment and choices. Convenience and taste have surpassed nutrition as the primary reasons for food selection.
Increased Availability of Ultra-Processed Foods: Food additives or processing technologies can extend shelf life. In their ready-to-eat form, these foods require no further preparation, making them easy to overconsume.
Over the past half-century, the refinement and continuous supply of these foods have increased. It is speculated that these foods, with higher energy density, availability, and convenience, are contributing to the global rise in obesity.
Societal and Commercial Pressures of Ultra-Processed Foods
Ultra-processed foods are often products with enhanced flavors, enticing people to consume more. People consume them because they taste good, not necessarily for nutritional needs.
Moreover, there is significant societal pressure to do so. The use of ultra-processed foods influences social trends, such as the consumption of fast food, restaurant and café dining, social activities, and celebratory events.
Many celebrations (Easter, Christmas, Halloween, birthdays, office parties, sports events, charity activities, and even national elections) now center around the consumption of ultra-processed foods.
