Zero-calorie sodas like Coke Zero and Sprite Zero are gaining popularity as “diet-friendly” choices. But do they really keep the weight off? Let’s take a closer look at what science says about artificial sweeteners, blood sugar, and insulin response.
The Truth About “0 Calories”
By food labeling law, if a serving contains less than 4 kcal, it can be labeled as “0 calories.”
This means that zero-calorie drinks may still contain trace amounts of energy.
But the real issue isn’t those tiny calories—it’s how these drinks affect blood sugar and insulin.
Blood Sugar and Insulin Response
When we eat, our blood sugar rises and insulin is secreted.
Insulin regulates blood sugar, but at the same time, it also acts as a fat-storage hormone.
So, to protect our health, we shouldn’t focus only on “calories = 0,” but also on the insulin response.
Zero-calorie drinks may not raise blood sugar directly,
but if insulin is secreted, it can still trigger fat storage.
That’s why we can’t simply say they “don’t cause weight gain.”
What Studies Show
Recent studies have found that artificial sweeteners in zero-calorie drinks can trigger insulin responses even when they don’t raise blood sugar.
Insulin Response by Artificial Sweetener
| Sweetener | Feature / Usage | Blood Glucose Response |
Insulin Response Findings |
| Aspartame | Widely used | No direct effect | Some studies show changes in insulin secretion |
| Sucralose | Common in Coke Zero, Sprite Zero | Minimal change | Multiple studies report increased insulin response |
| Saccharin | Old synthetic sweetener | Minimal effect | May disrupt gut microbiota → potential insulin resistance |
| Acesulfame K | Used in sodas, processed foods | No change | Some studies report increased insulin secretion |
| Stevia | Natural sweetener | Helps stabilize blood sugar | Generally safer, but long-term effects still debated |
So far, research suggests that artificial sweeteners are not necessarily safe just because they don’t raise blood sugar.
In Lies I Taught in Medical School by Robert Lufkin, MD, the author also warns about this issue. He emphasizes that artificial sweeteners can affect insulin response and metabolism, and we should not feel reassured simply because of the “0 calories” label.
In short, artificial sweeteners are not completely harmless.
If we truly care about our health, we must move away from the illusion that “sweetness is fine.” What matters more is changing our taste buds to depend less on sweetness itself.
Sweetness, as Addictive as Alcohol
Sweetness stimulates the brain’s reward system much like alcohol does.
Even though zero-calorie drinks provide little energy, they can make us crave even stronger sweetness over time.
This means the real problem isn’t just calories—it’s the vicious cycle of sweetness addiction.
Healthy Ways to Cut Back on Sweetness
- Use zero-calorie drinks only as an occasional substitute, not a daily habit
- Choose water, unsweetened tea, or sparkling water as your main drinks
- Retrain your taste buds to adapt to less sweetness
- Once you fully recognize the harm, you’ll find it easier to stay away
Conclusion
Zero-calorie drinks may help reduce calorie intake, but considering their effects on insulin response and sweetness addiction, it’s hard to call them completely safe.
If you want to protect your health, the real key is not just lowering calories, but changing your taste habits away from constant sweetness.
Over time, you may find yourself thinking, “I don’t really need this anymore.”
That realization could be the very first step toward better health.
