It’s a question I’m often asked by both parents and children when I’m delivering my school food education sessions. And I completely understand why. A can of regular Coca-Cola contains a substantial amount of sugar, while Coke Zero contains no sugar. So surely zero sugar must be the healthier choice?
Well… it’s a little more complicated than that.
I was reminded of this recently when I bought a drink with some pretty convincing messages on the can:
“Good for you”
Pre & probiotics
Natural flavours – pink grapefruit
Zero sugar
Great for the ocean – aluminium
Sounds pretty appealing, right? But when I turned the can around, I found erythritol (968) and steviol glycosides (960 and 960a) being used instead of sugar. This got me thinking about how easily we can equate “zero sugar” with “healthy”.
And that's something I think is worth taking a closer look at.
If you're comparing the two purely on sugar content, Coke Zero contains less sugar. But that doesn't automatically make it a 'healthy' everyday drink. Coke Zero is still a highly sweetened beverage. It simply gets its sweetness from different ingredients.
This is where I think the more useful question is: What role do sweetened drinks play in our everyday diet?
My advice to parents is generally not to get too caught up in choosing between regular Coke and Coke Zero. If it's an occasional drink, I'm not particularly worried. But if we're talking about what our children are drinking every day, water is still the drink we want to be consuming most often.
This is another reason I'm cautious about making zero-sugar drinks an everyday habit. Our taste preferences are influenced by what we're regularly exposed to. That doesn't mean drinking a Coke Zero will “ruin” a child's palate, but it does make me question whether we need to make highly sweetened drinks part of our daily routine.
The World Health Organisation recommends against using non-sugar sweeteners as a long-term strategy for weight control or preventing chronic disease. Its guidance also suggests reducing our overall preference for sweetness rather than simply replacing sugar with sweeteners.
So rather than constantly looking for the “better” sweetener, I think there's value in getting comfortable with less sweetness overall.
This is where the science gets interesting. Erythritol is a sugar alcohol, or polyol. It has very little effect on blood glucose, which is one reason it is commonly used in sugar-free products and low-calorie beverages generally.
Recent research raised questions about its potential cardiovascular effects, however the research is still developing so no need to panic.
Steviol glycosides are the intensely sweet compounds derived from the stevia plant. They're approved for use in Australia and New Zealand and have an established acceptable daily intake. There is also research exploring how sweeteners may interact with the gut microbiome.
But I wouldn't tell you that “stevia damages your gut.” The human evidence isn't strong enough to make that claim.
And that's an important lesson when we're reading nutrition headlines: interesting research isn't the same as proven harm.
This is probably my biggest takeaway. A product can contain ingredients that come from plants or occur naturally and still not be something we need to consume every day.
“Natural” isn't a synonym for healthy.
And neither is: “Zero sugar.”
These are pieces of information about a product — not a guarantee that it's a healthy choice.
I'm not anti-sweetener. And I'm not suggesting you throw out every zero-sugar product in your pantry. Instead, I'd encourage you to zoom out.
Ask yourself: What does my child drink most of the time?
Are sweetened drinks an occasional choice or an everyday habit?
Could water be the usual drink?
If the choice is between regular Coke and Coke Zero on the odd occasion, I'm not going to tell you that you've made a terrible choice either way. But I'd rather we didn't get stuck trying to identify the 'perfect' sweetener.
The goal isn't to find the perfect zero-sugar drink. It's to build a diet where we don't need everything to taste sweet. And that's a much more useful food conversation to have with our kids.