One of the most common questions dietitians are asked is “Is it OK to drink Coca-Cola Zero?” Here’s our answer!

There have long been discussions as to whether diet drinks are bad for your health, with reference to the sweetener used in them. You often see horror headlines suggesting that sweetener can cause type 2 diabetes, that it is carcinogenic, that it is more dangerous than ordinary sugar, that it can contribute to obesity, and so on. When research studies on animals have shown the negative effects of sweetener, the doses have been extremely high, much higher than what a human being would be able to ingest by consuming food containing sweetener. The studies were also badly designed. As we know, EVERYTHING is harmful if you ingest doses that are too high, even water! As sweetener has a sweeter flavour than ordinary sugar, only a small amount is required to sweeten drinks or other products.

Coca-Cola Zero Sugar contains the sweeteners aspartame and acesulfame K. Aspartame is the most researched food additive on the market. For an additive to be allowed to be used in food, it must undergo a number of tests and be assessed to be safe. There are currently no known risks associated with a ‘moderate’ consumption of food sweetened with aspartame, but the Swedish National Food Administration flags that we currently do not know how sweetener affects bacterial flora in our intestines and what consequences might follow. Animal experiments have in fact shown that certain sweeteners, including aspartame, affect bacterial flora in the intestines of mice.

Acceptable daily intake (ADI value)

There is an acceptable daily intake, established by the WHO, of aspartame that is at 40 mg per kilo of body weight and per day. This means that a person who weighs 60 kilos can ingest 2.4 g of aspartame per day without running any health risk. Drinks sweetened with aspartame may contain a maximum of 0.6 g of aspartame per litre, which means that a person who weighs 60 kilos can drink four litres of drink sweetened with aspartame per day before reaching those levels.

So, is it OK to drink Coca-Cola Zero?

Although Coca-Cola Zero, based on what we know today, does not appear to be harmful to health, it does not contribute with any nutrition either – it is therefore regarded as an unnecessary product. If you are using Coca-Cola Zero to satisfy a sugar craving, you should look over your general diet and make adjustments, a craving is generally a sign of an inadequate intake of nutritional food. However, having a diet drink every now and then is not a problem, and we consider it better to choose a drink that is sweetened with sweetener than one with ordinary sugar.

Sources Swedish National Food Administration. (2017). Aspartame. Accessed on 17 May 2018 from och Livsmedelsverket. (2017). Sweetener. Accessed on 17 May 2018 from