Is Coke Zero a good option for weight loss?

If you're trying to lose weight or prioritise your health, chances are you're probably trying to stay away from soft drinks and regular soda.

And if you're somebody who enjoys refreshing carbonated beverages, you might be opting for diet soda or 'zero sugar' options like Coke Zero instead in an effort to avoid weight gain.

Coke Zero is marketed as a lighter choice than Coca-Cola, and many people consider it a healthier alternative — particularly if they are trying to cut out regular soda.

A refreshing drink with zero calories sounds like a great option, but it might not be all good news.

Research has suggested zero-sugar and zero-calorie beverages could have a number of negative health effects, and could even potentially hinder your weight loss efforts. Here's what we know.

Is Coke Zero actually 0 calories?

According to the nutritional label on Coke Zero, a 375ml can contains 4.5 kilojoules, which is equivalent to about 1 calorie.

The label says 1 drink contains 0.09 grams of protein, 0 grams of fat, 0.1 grams of carbohydrates, and 0 grams of sugar.

A 375ml can of regular Coca-Cola contains 161 calories, with 0 grams of fat and 0 grams of protein. It contains 40 grams of carbohydrates, all of which are sugar.

This is virtually your entire recommended daily intake of sugar in 1 drink [1]. So a person who drinks multiple cans of Coca-Cola (or other sugar-sweetened beverages) is certainly going over the recommended daily sugar intake.

What are the ingredients in Coke Zero?

The ingredient label on cans of Coke Zero sold in Australia says the drink contains carbonated water, colour 150d (this gives the drink its caramel-brown colouring), food acids 338 (phosphoric acid) and 331 (sodium citrate), sweetener 951 (aspartame) and 950 (acesulfame potassium), flavour, and caffeine.

As we can see, Coke Zero does indeed have zero calories and no sugar, so it will not contribute to your calorie intake.

However, it also does not offer any nutrition and will most likely not keep you full for long — in fact, you could end up eating more food later in the day.

Can you drink Coke Zero every day?

While Coke Zero does not contain the high levels of sugar or calories that regular Coke does, it is not necessarily a healthy option, and it does not offer any nutritional benefits.

There are a number of reported side effects to Coke Zero, and drinking it every day could put you at risk.

More studies need to be done to fully determine the effects of Coke Zero on the body, but what we know so far indicates that while the odd drink is probably ok, it may be best to avoid drinking every day.

Why you should limit your diet soda intake

There are several factors as to why regularly drinking Coke Zero can be harmful, and it's not all about weight gain.

One thing to be aware of is the artificial sweetener aspartame, which is a key ingredient in Coke Zero and other artificially sweetened diet sodas.

It also appears in many low-calorie snacks and diet foods, so you may already be consuming it without even realising it. The problem is, there have been health concerns about frequent consumption of artificial sweeteners.

In 2023, the World Health Organization identified aspartame as possibly carcinogenic, which means it could have the potential to cause certain cancers [2].

However, this was based on limited studies and other organisations like the US Food and Drug Administration (FDA) have declared aspartame is safe for human consumption [3].

There have also been concerns about aspartame and other zero-calorie sweeteners causing gut health issues [4].

Research suggests that it does seem to impact the gut microbiome to some degree, but more investigation needs to be done [5].

The phosphoric acid in diet soda (and regular soda) can also be bad for your teeth [6], and some research has found artificial sweeteners can contribute to an increased risk of issues with blood sugar regulation, type 2 diabetes and cardiovascular disease [7].

Coke Zero also contains caffeine, and while caffeine is not inherently harmful, if you are drinking too much of it or drinking it close to bedtime, it can lead to poor sleep (and we know that getting enough sleep is a key element of health and weight management).

The WHO has also advised against using artificial sweeteners for weight loss and says there is not sufficient evidence that there are any real benefits compared with the negative effects [8].

Can Coca-Cola Zero make you gain weight?

While some believe diet drinks control hunger and can suppress appetite, or help prevent weight gain, this is not necessarily true.

Despite containing virtually no calories, Coke Zero and other types of diet soda have been associated with weight gain.

One study has found that people who drank artificially sweetened beverages had an increased risk of being overweight or obese [9], and another systemic review found a "significant association" between non-nutritive sweeteners and obesity [10].

Another study found diet soda may be linked with both having a higher waist circumference and metabolic syndrome [11].

There have also been concerns that consuming diet sodas and artificially sweetened food can actually lead to hunger, more cravings for sweet things, and increased food consumption.

Artificial and zero-calorie sweeteners often have a sweeter taste than sugar, and some researchers have suggested this could impact food preferences and increase the desire for sweet food [12].

Researchers have even found carbonated beverages could impact the body's production of the hunger hormone ghrelin, which can also impact how much you eat [13].

However, other research has found that diet soda has a positive association with weight loss, so again, more research may need to be done in the area [14].

If you are trying to lose weight and need some extra support, you could consider an option like Juniper's Weight Reset. The programme works to target your metabolism and is designed to help you lose weight and keep it off — for good.

It combines weight loss medications (Wegovy or Mounjaro) with health tracking, lifestyle coaching, and a supportive community to help you make sustainable lifestyle changes.

The medication helps you regain the mental space to create healthy habits that stick, as well as understand your hunger signals and respond to them on your terms — so you can stop reaching for high-calorie foods and sugary drinks.

What to drink instead of Coke Zero

Despite these health risks, the occasional Coke Zero is ok. But as we have discussed, it is probably not something you should be drinking every day.

For a healthier refreshing drink, you could try fruit-infused water, unsweetened tea, kombucha, or carbonated water without artificial sweetener or flavour added.

You can also opt for fruit juice, but make sure to check the ingredients and sugar content as these can often be very sweet and have a high amount of added sugar.

As we have mentioned, you don't need to completely cut diet soda out of your life forever, but you can begin swapping it out for healthier options.

It's important to enjoy food and drinks, but it's also important to make sure you are looking after your body and meeting your nutritional needs — it's all about balance!