What is Diet Squirt sweetened with? The zero-calorie citrus breakdown

December 30, 2025 •

3 min read

Introduced in 1983, Diet Squirt was one of the first soft drinks in the United States to be sweetened with aspartame. Today, the zero-calorie citrus soda uses a precise blend of both aspartame and acesulfame potassium, often called Ace-K, to deliver its signature crisp taste without the sugar.

Quick Summary

The low-calorie version of Squirt soda achieves its sweetness from a combination of aspartame and acesulfame potassium. This zero-calorie mix provides the familiar grapefruit and citrus taste without using high-fructose corn syrup.

Key Points

Primary Sweeteners: Diet Squirt uses a blend of two zero-calorie artificial sweeteners, aspartame and acesulfame potassium (Ace-K).
Flavor Profile: The combination of sweeteners provides a more balanced and sugar-like taste than using a single sweetener alone, avoiding a strong aftertaste.
Phenylalanine Warning: Due to the aspartame, Diet Squirt contains phenylalanine, requiring a warning label for individuals with the metabolic disorder phenylketonuria (PKU).
No Sugar or HFCS: Unlike regular Squirt, the diet version contains zero sugar and no high-fructose corn syrup, making it a zero-calorie option.
Comparison to Mexican Squirt: The US and Mexican versions of Diet Squirt use different sweetener blends. Mexican Squirt has been noted to use sucralose and acesulfame-K.

The Zero-Calorie Sweeteners in Diet Squirt

Diet Squirt is primarily sweetened with a combination of two non-nutritive, or zero-calorie, artificial sweeteners: aspartame and acesulfame potassium. This blend is a common industry practice designed to produce a more balanced flavor profile than using a single sweetener alone. Each plays a distinct role in creating the final taste.

Aspartame: The Primary Sweetener

Aspartame is a very common artificial sweetener, sold under brand names like NutraSweet, and was a pioneering ingredient in diet sodas. It is a methyl ester of the aspartic acid/phenylalanine dipeptide, which is broken down into its constituent amino acids after consumption. Aspartame provides a clean, sugar-like sweetness and is a crucial component of Diet Squirt's flavor. However, it is not heat-stable and contains phenylalanine, so products containing it must carry a warning label for people with phenylketonuria (PKU).

Acesulfame Potassium (Ace-K): The Flavor Enhancer

Often used in tandem with other sweeteners, acesulfame potassium (Ace-K) is a stable, non-caloric sweetener. It is known for having a rapid onset of sweetness, but can also have a slight aftertaste when used alone. When combined with aspartame, Ace-K's properties are highly complementary. The blend provides a more complete, rounded sweetness and helps mask any potential lingering aftertaste from the aspartame.

Why Use a Sweetener Blend?

Using a blend of aspartame and acesulfame potassium offers several advantages for beverage manufacturers, primarily focused on achieving the optimal consumer experience. For Diet Squirt, this combination is key to replicating the crisp, refreshing taste of the original soda without the calories of high-fructose corn syrup. The synergy between the two compounds creates a sweetness profile that is greater than the sum of its parts.

Masking Off-Flavors: Combining sweeteners can effectively mask any undesirable aftertastes that might be associated with a single artificial sweetener.
Synergistic Effect: The sweetness intensity of the blend is often higher than the individual sweeteners used alone, allowing for a smaller total amount to be used.
Mimicking Sugar's Profile: Each sweetener has a slightly different taste curve. Aspartame's sweetness lasts longer, while Ace-K provides an immediate punch. The combination provides a sweetness that closely resembles the flavor profile of real sugar.

Comparing Sweeteners in Squirt Sodas

To understand what is in your drink, it's helpful to compare the different versions of Squirt on the market. The sweetener varies significantly between the regular, diet, and sometimes regionally specific versions.


Product	Sweetener(s) Used	Notes
Diet Squirt (US)	Aspartame, Acesulfame Potassium	A zero-calorie blend designed for the US market.
Regular Squirt (US)	High Fructose Corn Syrup	Contains added sugar and calories.
Mexican Squirt	Sucralose (Splenda), Acesulfame-K	A different, low-calorie formulation due to local tax laws.

Other Ingredients Found in Diet Squirt

While the sweeteners are the defining component for its zero-calorie status, Diet Squirt contains several other ingredients that contribute to its flavor, texture, and stability.

Carbonated Water: The base of the soda, providing fizz.
Grapefruit Juice Concentrate: Added for the core grapefruit flavor, though in very small amounts (less than 2%).
Natural Flavors: Additional flavorings to round out the citrus profile.
Citric Acid: Provides a tartness that complements the grapefruit flavor.
Modified Corn Starch & Ester Gum: These emulsifiers and stabilizers help to disperse the flavor oils throughout the beverage.
Preservatives: Sodium benzoate and calcium disodium EDTA are used to protect the flavor and freshness of the soda over time.

Conclusion: The Final Sweet Verdict

In summary, if you've ever wondered what is Diet Squirt sweetened with, the answer is a combination of aspartame and acesulfame potassium. This intentional blend of artificial sweeteners is crucial for replicating the taste of the original sugary version without adding any calories. This formulation has been a staple since Diet Squirt's early days, providing a reliable, sugar-free alternative for those seeking the crisp, citrusy flavor they love.

Frequently Asked Questions

No, Diet Squirt does not contain high-fructose corn syrup. That sweetener is used in the regular, sugary version of Squirt. The diet version relies on artificial sweeteners instead.

No, individuals with PKU should avoid Diet Squirt. Because it contains aspartame, it is a source of phenylalanine, which people with PKU cannot metabolize.

Using a blend of sweeteners like aspartame and acesulfame potassium helps create a more well-rounded flavor profile. The combination provides a more natural, sugar-like sweetness and masks any potential aftertastes associated with a single sweetener.

Yes, for the US market, Diet Squirt and Squirt Zero Sugar refer to the same zero-calorie, sugar-free product, which contains aspartame and acesulfame potassium.

Yes, while designed to taste similar, the flavor profiles differ due to the sweeteners used. Diet Squirt's sweetness comes from artificial sweeteners, which can have a slightly different mouthfeel and taste, while regular Squirt is sweetened with sugar.

Yes, reports indicate that Mexican-market versions of Squirt may use a different blend of low-calorie sweeteners, such as sucralose (Splenda) and acesulfame-K, due to various regional factors.

Yes, Diet Squirt is caffeine-free. This is a consistent feature of the product across different variants, unlike some other sodas that offer a diet option with caffeine.