Q. What's the difference between Diet Coke and Coke Zero?

on Thursday, 12 September 2013. Posted in Additives & labels
Tagged: caffeine, calories, dieting, diets, drink, drinks

A. At first glance, Diet Coke and Coke Zero appear to be identical. Both contain no kilojoules (calories) and no sugar. Both are artificially sweetened with (the same amount) of aspartame and acesulfame K and therefore have the same ‘sweetness’.



However, there are three very subtle differences between Diet Coke and Coke Zero:

1. Since its launch in 1982, Diet Coke has been popular with people conscious of their weight, especially women. In 2005 Coca Cola Amatil launched a similar product, Coke Zero, but with more ‘masculine’ looking packaging to appeal to males. Coke Zero has even beennicknamed "Bloke Coke".

2. Although they both contain caffeine, the amount varies: Coke_Diet_Zero

Regular Coke               9.7 mg/100ml

Diet Coke                     12.8 mg/100ml

Coke Zero                    9.6mg/100ml

Therefore, the amount of caffeine in Coke Zero is almost identical to that of Regular Coke and higher in Diet Coke. Most consumers would agree that Coke Zero tastes more like regular coke. This could be due to both having virtually the same amount of caffeine.

3. The food acids used are different. Regular Coke contains 338 (phosphoric acid), Diet Coke contains 338 and 330 (citric acid), whilst Coke Zero contains 338 and 331 (sodium citrate). Not much of a difference really but at least you know.

And which is the most popular?

American statistics suggest that Regular Coke is the highest selling soft drink and Diet Coke is third. Coke Zero has never made it in the Top 10 list, but is apparently slowly growing in popularity.

So which is the best to drink? We advocate water as the ideal drink. Add lemon or lime to make it taste nicer. We don’t recommend you drink ordinary soft drink. There’s  nothing nutritious or healthy about soft drink. But if you’re need to lose weight or have type 2 diabetes, diet drinks can make your life more pleasant without adding kilojoules. Drink them occasionally say if you’re out. Even without sugar, you’re still consuming something sweet and your taste buds get used to that level of sweetness. The odd one when you’re out is fine but don’t make a habit of them.  See here for reasons why. And their acidity and phosphoric acid is not healthy either. It can damage tooth enamel which contributes to dental erosion.

INGREDIENTS FOR COMPARISON (taken directly from the label):

Ingredients in Diet Coke

Carbonated purified water, flavour, colour (caramel 150d), food acid (338, 330), sweeteners (951,950), preservative 211, caffeine.

Ingredients in Coke Zero
Carbonated purified water, colour (caramel 150d), food acid (338, 331), flavour, sweeteners (951,950), preservative 211, caffeine.
Ingredients in Coca Cola regular

Carbonated purified water, cane sugar, colour (caramel 150d), food acid 338, flavour, caffeine.

Note: Preservative 211 is sodium benzoate which is commonly used to extend the shelf -life of soft drinks, cordials and fruit drinks. It is needed in both sugar-free diet drinks but NOT in the regular Coke as the sugar does the job of preserving the drink witout refrigeration.


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Comments (8)

  • Simon


    18 November 2011 at 14:06 |
    Had a customer ask what the difference was between diet coke and coke zero, because her daughter only drinks coke zero and dislikes diet coke. I looked at the ingredients and it was almost identical. Next time i see the lady i will now be able to explain about the caffiene content. I agree heaps of blokes buy coke zero.
  • Fiona


    10 February 2013 at 11:22 |
    Question what about diet coca cola caffeine free what's the stats on it
  • Theo


    19 March 2014 at 16:39 |
    The difference in caffeine levels between Diet Coke and Coke Zero is very low, and not discernable to any consumer during consumption and absorption of standard or large quantities of the beverage. Food acid 330 inhibits the ability of certain receptor cells to absorb caffeine, thus the caffeine level in Diet Coke is increased slightly to offset this affect. The Coke Zero brand overcame the issue of cell-inhibiting by using food acid 331 (a genetic modification of food acid 330). Any differences between the two non-sugar Coke varieties is related to the consumer expectations created primarily by the marketing of the product.
    • Catherine Saxelby

      Catherine Saxelby

      24 March 2014 at 19:07 |
      Thanks for that techie explanation Theo. Agree wtih you that the difference is minimal which is why we looked into it in the first place. Marketing has a lot to explain here I guess. Catherine
  • Michael


    03 April 2014 at 02:02 |
    The primary difference is actually in the "flavour" ingredients. It's a closely guarded trade secret exactly what they are, but most colas contain 10-20 different extracts (vanilla, cinnamon, citrus, vegetables etc.) and the balance in Diet Coke and Coke Zero is different. Personally I think Diet Coke tastes slightly more of citrus and hibiscus whereas Coke Zero tastes more of cinnamon.
  • Hui Xian

    Hui Xian

    08 May 2014 at 21:41 |
    Will it be correct to say that Regular Coke is the lesser of three evils since regular coke has cane sugar and the other two have artificial sweetener?
  • Elan


    28 May 2014 at 12:47 |
    The only time coke uses cane sugar is during the Jewish Passover holiday, it make it drinkable for those who observe that holiday.
    Otherwise Coke uses corn syrup!!!!

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