Do Fizzy Drinks Fill You Up? The Surprising Truth
Fizzy drinks can create a feeling of fullness due to carbonation, but they often contain empty calories and may not satisfy hunger effectively.
Many people reach for carbonated beverages thinking they’ll curb hunger, but science reveals a more complex story. While the bubbles may create temporary fullness, research shows fizzy drinks can actually trigger increased hunger hormones and lead to overeating.
How Carbonation Affects Your Appetite
The fizz in your drink comes from carbon dioxide gas, which interacts with your digestive system in unexpected ways. Studies from Birzeit University and UCLA found that both sugary and sugar-free carbonated drinks stimulate ghrelin production – the “hunger hormone” – by up to 50% compared to flat beverages.
The Ghrelin Effect
When researchers measured participants’ blood after drinking carbonated beverages, they discovered:
- 50% higher ghrelin levels after carbonated drinks vs flat drinks
- 120 more calories consumed later in the day
- Similar results for both sugary and diet versions
Why This Happens
Scientists propose two mechanisms:
- CO2 triggers stomach receptors that stimulate ghrelin release
- Gas bubbles stretch the stomach lining, activating hunger signals
Carbonated Water vs Sugary Sodas
While plain sparkling water seems harmless, even unsweetened carbonated water showed these effects in studies. However, switching to sugary flat drinks isn’t the answer. The calories from sugar outweigh any benefits from reduced carbonation.
| Drink Type | Ghrelin Increase | Calorie Impact |
|---|---|---|
| Regular Soda | High | Very High |
| Diet Soda | High | Low |
| Sparkling Water | Moderate | None |
| Flat Water | None | None |
The Best Alternatives
For true appetite control without the hunger spike:
- Plain water (add lemon or cucumber for flavor)
- Herbal teas
- Homemade digestive-friendly smoothies
- Fresh vegetable juices from a quality juicer
Practical Tips for Carbonation Lovers
If you can’t give up fizz entirely, try these strategies:
- Drink carbonated beverages with meals, not between
- Choose smaller serving sizes
- Let drinks go slightly flat before consuming
- Pair with high-fiber foods to offset hunger signals
According to UCLA Health research, even unsweetened carbonated water showed these effects in human trials. Meanwhile, the BBC’s experiment confirmed these findings with 20 human volunteers.
When Carbonation Helps
Interestingly, carbonation may benefit some people in specific situations:
- Post-surgery patients needing gentle hydration
- Those experiencing nausea (ginger ale is a classic remedy)
- People transitioning from sugary sodas to sparkling water
The Bottom Line
While fizzy drinks create temporary fullness from gas expansion, they trigger biological processes that may lead to increased hunger and calorie consumption later. For sustainable appetite control, flat beverages – especially water – remain the best choice. If you enjoy carbonation, being mindful of timing and portion sizes can help mitigate the hunger hormone effects.
