Ultra Processed Food List

Processing Level Index Methodology

Understanding how food processing affects your health and how we calculate our 1-10 scale.

What is the Processing Level Index?

The Processing Level Index (PLI) is a proprietary scale developed by Ultra Processed Food List to help consumers understand the degree of processing in food products. The PLI assigns a score from 1 to 10 to each food product, with higher numbers indicating more extensive processing.

Scale Interpretation

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Minimally Processed (1-3)

Foods that have undergone minor processing while retaining most of their inherent nutritional and physical properties.

Examples: Washed vegetables, refrigerated milk, frozen fruits without additives, dried beans, roasted nuts.

Processing Level: 2 out of 10 - Minimally Processed
2/10
Minimally Processed

Moderately Processed (4-6)

Foods that have been altered more significantly but still contain recognizable ingredients.

Examples: Bread made with flour, water, salt, and yeast; canned vegetables with limited additives; cheese; pasta; tofu.

Processing Level: 5 out of 10 - Moderately Processed
5/10
Moderately Processed

Ultra-Processed (7-10)

Formulations made mostly or entirely from substances derived from foods and additives, with little to no intact food. These typically contain ingredients you wouldn't find in a home kitchen.

Examples: Carbonated soft drinks, mass-produced packaged breads, instant noodles, reconstituted meat products, pre-made frozen dishes.

Processing Level: 9 out of 10 - Ultra Processed
9/10
Ultra Processed

Calculation Methodology

Our Processing Level Index is calculated using a proprietary algorithm that evaluates multiple factors derived from the ingredient lists and nutritional information obtained from the USDA FoodData Central API. The primary factors include:

1. Ingredient Analysis

We analyze the ingredient list for indicators of processing, such as:

  • Presence of ultra-processed ingredients (e.g., high-fructose corn syrup, hydrogenated oils, hydrolyzed proteins, artificial sweeteners, colors, flavors)
  • Presence of processed ingredients (e.g., refined flours, added sugars, maltodextrin, protein isolates)
  • Presence of minimally processed indicators (e.g., 'organic', 'whole grain', simple ingredient lists)
  • Total number of ingredients (longer lists often indicate higher processing)

2. Additives Evaluation

We analyze the presence and number of food additives, with special emphasis on:

  • Artificial preservatives (e.g., sodium benzoate, potassium sorbate)
  • Artificial colors (e.g., Red 40, Yellow 5)
  • Artificial flavors
  • Emulsifiers (e.g., lecithins, mono and diglycerides)
  • Stabilizers (e.g., guar gum, carrageenan)
  • Sweeteners (e.g., aspartame, sucralose)
  • Flavor enhancers (e.g., monosodium glutamate)

The greater the number and variety of additives typically associated with industrial processing, the higher the PLI score.

3. Nutrient Profile

We consider aspects of the product's nutrient profile that may indicate processing:

  • Very high sugar content relative to the food category
  • Very high sodium content relative to the food category
  • Very high fat content, particularly trans fats or certain saturated fats
  • Very low fiber content in grain products relative to whole counterparts

Significant deviations from typical nutrient profiles of less processed foods contribute to the score.

Calculation Approach

The PLI is calculated using a weighted algorithm that assigns points based on the factors listed above:

  1. Analysis of each ingredient against known lists of minimally processed, processed, and ultra-processed components.
  2. Evaluation of the number and type of additives.
  3. Assessment of the overall nutritional profile compared to less processed benchmarks.
  4. Consideration of the total number of ingredients.

These factors are combined and weighted to produce a score, which is then normalized to the 1-10 PLI scale.

Limitations

We acknowledge several limitations to our methodology:

  • Data Completeness: Our analysis depends on the completeness and accuracy of the USDA FoodData Central database.
  • Ingredient Quantities: We cannot determine the exact quantities of ingredients, only their presence.
  • Regional Variations: Product formulations vary by country and region, which may not be fully captured in the database.
  • Processing Techniques: Not all processing techniques are explicitly listed and must be inferred from ingredients.
  • Evolving Science: Our understanding of food processing and its impacts continues to evolve.
  • Algorithm Refinement: Our algorithm is continually being refined as we gather more data and feedback.

Not a Health Rating

It's important to note that the Processing Level Index indicates the degree of processing, not necessarily the healthfulness of a food. While many highly processed foods are associated with less favorable health outcomes, the PLI alone should not be used to determine the overall nutritional value of a food.

Individual dietary needs vary, and some processed foods may be appropriate in certain contexts. We encourage users to consider the PLI as one factor among many when making food choices.

Last Updated: March 2025