Diet Coke vs Coke Zero – Which Is Worse For Your Health?

Diet Coke

It was the first sugar-free cola from the Coca-Cola Company and was launched in 1982. Since its launch, it has been popular with people conscious of their weight, particularly women.

It is the best-selling diet soda worldwide. However, it has been losing market share to healthier alternatives. For instance, it has dropped from $4.4 billion in sales in 2005 to $3.2 in 2016.


This drink contains – caramel color, carbonated water, phosphoric acid, artificial sweetener (aspartame), natural flavors, potassium benzoate, caffeine, and citric acid.

Coke Zero

It made its debut in 2005 and was one of the top carbonated drinks in 2016. Coca-Cola Zero Sugar replaced this drink, and it is similar but with a few changes. The upgraded recipe is produced with an even better-tasting recipe (the development took five years) which delivers real Coca-Cola taste with zero calories and zero sugar.


This drink contains – caramel color, carbonated water, artificial sweetener (aspartame), potassium benzoate (to protect taste), phosphoric acid, acesulfame potassium, natural flavors, caffeine, and potassium citrate.

Side Effects

Potassium Citrate

It is actually a citrate salt of potassium which has the capacity to lower acid levels in the body. It is known as E number E332 in the European Union. As a food additive, this substance is used to regulate acidity, and, medicinally, E332 may be used to control kidney stones produced from either cystine or uric acid.

Side effects of consuming processed foods that contain potassium citrate include – rapid weight gain, numbness, slow or fast or heart rate, muscle twitching, mood changes, confusion, severe stomach pain, seizure, tarry or bloody stools, ongoing diarrhea.

Phosphoric Acid

Phosphoric acid (chemical formula – H3PO4) is a chemical with a variety of applications in both food processing and industry. Moreover, it is an ingredient in over-the-counter anti-nausea drugs. According to research, a high intake of foods containing phosphoric acid stimulates the secretion of the parathyroid hormone that in turn can lead to heart disease and bone mineral density loss.

Potassium Benzoate

It is a chemical preservative that is usually added to some drinks and processed foods, however, it is most notably used in soft drinks since adding just a small amount can help prevent the growth of yeast, mold, and certain bacteria in foods.

The problem is that when potassium benzoate is combined with the ascorbic acid (the synthetic form of vitamin C) in drinks, it can form benzene – a carcinogen. Also, there have been reports that a small percentage of consumers may have allergic reactions.


It is an artificial sweetener that is commonly sold under the brand names of Equal, NutraSweet, Blue Zero Calorie Sweetener Packets. It is about 200 times sweeter than table sugar.

Human reports to FDA have linked consumption of foods containing this artificial sweetener to the following adverse reactions – change in vision, migraines, panic attacks, sleep problems, vomiting, nausea, change in heart rate, anxiety, dizziness, depression, abdominal pain, seizure, joint pains, brain cancer, and memory loss.

It has carcinogenic effects, and a re-evaluation of the current position of international regulatory agencies must be considered, according to a 2014 research by a longtime cancer research center – the Ramazzini Institute, Bologna, Italy.

Acesulfame Potassium

It is also known as Ace K or acesulfame K and is a calorie-free artificial sweetener usually marketed under the trade names Sweet One and Sunett. This artificial sweetener is commonly used in combination with another artificial sweetener – aspartame.

Both these artificial sweeteners are suspected carcinogens, with Aces K having more negative studies attributed to it.


Whether caffeine is consumed as a medicine or in food and drinks, it changes the way you behave and feel.

Too much intake of caffeine can produce numerous adverse effects including – nausea, vomiting, tremors, restlessness, upset stomach, anxiety, sleep difficulties, dehydration, depression, increased urine production, difficulty sleeping, and irregular heartbeats.

Bottom Line – Diet Coke vs Coke Zero

Both these carbonated drinks have a similar ingredients list, with the only important difference being the proportions of the ingredients that actually give them different flavor profiles. Another important difference is that Coke Zero Sugar contains two extra sweeteners (potassium citrate and acesulfame potassium) not found in Diet Coke.

Both drinks are calorie-free and sugar-free and are both artificially sweetened. Hence, they have the same level of sweetness. Also, there is no nutrition in them as both are nothing but empty calories.

Even though these soft drinks contain no calories, they still might lead to weight gain. For example, individuals who drank any type of diet soda were just as likely to gain weight as individuals who consumed regular soda, according to a 2010 article published in the “Yale Journal of Biology and Medicine.”

Moreover, artificial sweeteners are linked to a higher incidence of cardiovascular problems, according to a 2017 study conducted by the Canadian Medical Association Journal. More importantly, research establishes a strong association between the consumption of carbonated drinks and mental health issues.

Lastly, according to a University of Minnesota study, intake of one diet soda every day was associated with more than 35 percent increase in the risk of diabetes and metabolic syndrome.

Image credit – Shutterstock

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1 thought on “Diet Coke vs Coke Zero – Which Is Worse For Your Health?”

  1. Many people drink these sodas to avoid weight gain and a decrease in getting diabetes or any other health problems. If drinking diet cokes and zero sugar cokes also increase these same health risk, why should we drink them? I’m so confused. Ugh!


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