Quick answer
Equal processing levels. Diet soda eliminates sugar calories but replaces them with synthetic sweeteners. Sparkling water is the only truly less-processed alternative.
Processing levels can vary significantly between brands and specific products within each category. Always check the ingredient list of the specific product you are considering. Use our product search to look up exact processing scores. These comparisons evaluate processing level and ingredient composition only. They do not account for taste, price, convenience, cultural significance, or individual dietary needs.
How do they compare by the numbers?
Sample products from each
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Frequently asked questions
Is diet soda less processed than regular soda?
No. Both score as ultra-processed in our analysis. Diet soda removes the high fructose corn syrup but replaces it with synthetic sweeteners like aspartame and acesulfame potassium, swapping one industrial ingredient for another.
What is a less processed alternative to soda?
Sparkling water with a squeeze of citrus is the closest swap, typically scoring Level 1 in our analysis. It keeps the carbonation without the sweeteners, colors, and acids found in soda formulations.