Is Diet Soda Ultra Processed?
Yes — Ultra-Processed
Diet soda is ultra-processed (Level 4). It replaces sugar with synthetic sweeteners (aspartame, sucralose, acesulfame potassium) that are manufactured through chemical synthesis. Caramel color in cola varieties is produced by heating sugar with ammonia, creating 4-methylimidazole (4-MEI) as a byproduct.
Key Findings
- •Artificial sweeteners in diet soda are among the most chemically engineered molecules in any common food product
- •Caramel color (Class IV) is produced through the ammonia-sulfite process, creating 4-methylimidazole — listed as a potential carcinogen under California's Proposition 65
- •Sparkling water with real fruit juice provides carbonation and flavor at Level 1 without any synthetic chemicals
Why Is Diet Soda Ultra-Processed?
Diet soda is often perceived as a healthier alternative to regular soda, but from a processing standpoint it is equally industrial. Aspartame is synthesized from phenylalanine and aspartic acid through bacterial fermentation and chemical coupling. Sucralose is made by chlorinating sugar molecules (replacing three hydroxyl groups with chlorine atoms). Acesulfame potassium (Ace-K) is a potassium salt produced through chemical synthesis. These artificial sweeteners are among the most heavily engineered molecules in the food supply. Caramel color in cola-type diet sodas is not simply "heated sugar" — it is produced through the ammonia-sulfite process (Class IV caramel), which creates 4-methylimidazole (4-MEI), a compound California lists under Proposition 65 as a potential carcinogen. Phosphoric acid, sodium benzoate (preservative), and proprietary "natural flavors" complete the industrial formulation.
Diet Soda Processing Level Distribution
How 1,000 diet soda products break down by processing level:
Average ingredient count: 8.9 · Average nutrition score: 5.0/10
Diet Soda Brand Comparison
Comparing the least to most processed diet soda products in our database:
| Product | Brand | Level | Score | Ingredients |
|---|---|---|---|---|
| Caffeine Free Cola Zero Sugar Soda, Caffeine Free Cola | Zevia | Processing Level: 2 out of 4 - Processed | 3.5 | 5 |
| Ginger Root Beer Zero Sugar Soda, Ginger Root Beer | Zevia | Processing Level: 2 out of 4 - Processed | 3.5 | 4 |
| Black Cherry Zero Sugar Soda, Black Cherry | Zevia | Processing Level: 2 out of 4 - Processed | 3.5 | 4 |
| Grape Zero Sugar Soda, Grape | Zevia | Processing Level: 2 out of 4 - Processed | 3.5 | 4 |
| Creamy Root Beer Zero Sugar Soda, Creamy Root Beer | Zevia | Processing Level: 2 out of 4 - Processed | 3.5 | 4 |
| Strawberry Zero Sugar Soda, Strawberry | Zevia | Processing Level: 2 out of 4 - Processed | 3.5 | 4 |
| Cream Zero Sugar Soda, Cream | Zevia | Processing Level: 2 out of 4 - Processed | 3.5 | 4 |
| Ginger Ale Zero Sugar Soda, Ginger Ale | Zevia | Processing Level: 2 out of 4 - Processed | 3.5 | 5 |
| Orange Zero Sugar Soda, Orange | Zevia | Processing Level: 2 out of 4 - Processed | 3.5 | 4 |
| Creamy Root Beer Zero Sugar Soda, Creamy Root Beer | Zevia | Processing Level: 2 out of 4 - Processed | 3.5 | 4 |
How to Read Diet Soda Labels
- 1
Aspartame, sucralose, and acesulfame potassium are all synthesized chemicals, not natural sweeteners
- 2
Caramel color (in cola varieties) is Class IV caramel produced using ammonia — not simple heated sugar
- 3
Phosphoric acid provides the tart bite in cola — it is industrially manufactured
- 4
Sodium benzoate (preservative) can form benzene when combined with ascorbic acid (vitamin C)
Frequently Asked Questions
Is diet soda better than regular soda?
Diet soda has zero calories but is equally ultra-processed (Level 4). It replaces one industrial ingredient (HFCS/sugar) with other industrial ingredients (synthetic sweeteners). From a processing standpoint, neither is better. Sparkling water (Level 1) is the less processed carbonated alternative.
What is caramel color really made from?
Class IV caramel color used in cola is not simple heated sugar. It is produced by reacting sugar with ammonia and sulfite compounds under high pressure, creating the brown coloring along with 4-methylimidazole (4-MEI), a byproduct that California lists as a potential carcinogen.
Are zero-calorie sodas less processed than diet soda?
No. "Zero sugar," "zero calorie," and "diet" sodas all use the same synthetic sweeteners and industrial ingredients. The different names are marketing distinctions, not processing differences.