Diet Soda vs. Normal Soda: Which one is better?


I’m sure I will surprise no-one when I say that the average Australian has too much added sugar in their diet. Reducing sugar intake is a hot topic in the health industry now. There are many ‘sugar-free’ diets gaining popularity and the World Health Organisation even released guidelines for a reduction of added sugar in our diets. Their suggestion? Having less than 10% of our daily intake coming from added sugar. To learn more about added vs. natural sugar, check out my blog article here.

What is the difference between diet soda and normal soda?

Diet drinks contain artificial sweeteners that replace sugar in food and drinks to make them sweet. There are a variety of artificial sweeteners available, including saccharin, aspartame and cyclamate. In Australia, aspartame, is commonly used although there other types of sweeteners  are used. Normal soda contains sugar or syrup to create sweetness. 

A spoonful of sugar

First of all, lets have a look at what sugar-sweetened soft drinks can do to our bodies.

  • Dental problems. Sugar is a huge offender for dental problems. If a person isn’t taking care of their teeth it can result in dental caries. Dental caries is a fancy word for rotting teeth. Seriously, I’ve seen the photos and it ain’t pretty. Not only do teeth problems look bad, but they cause pain and cost a LOT to fix.
  • Empty calories. A glass of soft drink literally has no nutrition aside from the calories. No vitamins, no minerals, no fibre, nothing beneficial! Soft drinks won’t make you feel full, so it’s easy to eat as normal, and have the calories from the drink. It’s just a glass of weight gain waiting to happen!
  • Sugar levels. A can of soft drink has about 10 teaspoons of sugar in it (yes Coke I am looking at you over there). Having this much sugar at once is going to send blood sugar levels sky high.  While it might provide a boost of energy, the subsequent energy crash once your blood sugar levels drop is going to result in a daytime nap, or seeking out  another sugary energy hit.
  • Cost. Soft drink is expensive. At my local shop a popular brand is around $2.80 a can. If you break it down – it’s water, some flavourings and colours with some sugar or syrup thrown in for sweetness. Buy a fresh lemon for $1.00 and a bottle of generic brand mineral water for 75 cents and it makes a much cheaper and healthier alternative!

What about diet drinks?

Now the question that’s been sitting on the tip of the tongue since you started reading this…

Do diet drinks cause cancer?

A report in the 1990s suggested the increase of people with brain tumours may be associated with the introduction and use of artificial sweetener in the United States. When the US National Cancer Institute statistics were analysed, it showed the incidence of cancers began to rise eight years before the approval of aspartame. Further, the cancers rose mainly among people aged 70 and older, a group who doesn’t have the highest exposure to aspartame.

Research on the safety of sweeteners found there was no evidence to support any link to cancer and artificial sweeteners in humansRat. Research on rats did show high levels of aspartame increased the risk of developing lymphoma and leukaemia. But the doses of aspartame the rats were given was equivalent of 8 – 2,083 cans of diet soft drink daily.

So if someone has 2,000 cans of diet soda a day then yes, I’d recommend they stop such an expensive and unhealthy habit. Let’s just aim for less than 8 cans a day (!).

Australia’s leading food safety organisation, FSANZ, found that consumption is well below the levels at which health problems could occur. What does that mean? Our society’s current daily intake for aspartame is safe.

Diet drinks and weight gain

Diet drinks are marketed as the better option for weight loss. Therefore it’s often chosen by people wanting to lose or maintain weight. Perplexing then, that recent research suggests artificial sweeteners may actually contribute to weight gain.  Bearing in mind this is fairly new research, but experiments have found that a sweet taste (be it from sugar or sweeteners), boosts appetite. While the studies were small, it’s an area gaining traction in research.

Why is this? Two theories abound. 

First. Tasting anything sweet triggers a neurological response. Sugar activates  the parts of the brain involved in food reward.  This releases happy feelings. When sweeteners are consumed, MRI scans show that different areas of the brain are activated. This suggests the sweetener may not satisfy your desire for sweet foods. So, while sugar signals a positive feeling of reward, artificial sweeteners may not be an effective way to manage a craving for sweets. Someone might therefore eat more sweet foods to satisfy that craving. 

Two. Artificial sweeteners, precisely because they are sweet, encourage sugar craving and sugar dependence. Repeated exposure trains our taste buds to prefer that flavour.  A link exists between what someone eats and their preferred intensity for that flavor, be it salty, sweet or spicy food. The more we eat of it, the more we want it.

The final sip

So having said all that, is it better to have diet drinks?


In terms of reducing dental problems, maintaining blood sugar levels and reducing calorie intake, diet soft drinks are a better option. This is especially true if you are diabetic. Controlling blood sugar levels can be hard and diet soft drinks don’t affect blood sugar levels. However, a better alternative is if you are trying to wean yourself from sugary soda, use diet soda in the short-term. Aim to cut all types of soft drink from your diet and save yourself some money as well!

2 Comments Add yours

  1. temptnutrition says:

    Excellent explanation. You may be on the other side of the world from the USA but our nutritional concerns are still the same.
    Your soda seems pricier though and we are starting to move to sucralose in our diet sodas.

    1. Thanks for your comment. Australian food is quite expensive compared to elsewhere I think! I am interested in the other sweeteners being used too, so may do a follow up post looking at those!

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