But research shows they could pose bigger risks too - they could even increase your risk of cancer, heart disease or a stroke.
A new study of 2,500 people found that people who drink diet fizzy drinks every day have a 61% higher chance of having a heart attack or stroke than people who didn't drink any fizzy drinks. This is worrying for many of us who chose diet drinks as a healthier alternative.
Dr Sharlin Ahmed from The Stroke Association said: 'According to this study drinking diet fizzy drinks on a regular basis could pose the same or even higher risk for cardiovascular disease as standard fizzy drinks.'
However, Hannah Gardener, who led the study, admitted that more research was needed to confirm these findings.
A study from just a few months ago found that drinking 2 fizzy drinks a week could nearly double your risk of pancreatic cancer.
Researchers carried out a study of 60,000 people from Singapore over 14 years. They found that the risk of developing the disease was linked to eating too much sugar - and those who drank fizzy drinks two or more times a day were at the highest risk. Of those 60,000, 140 developed pancreatic cancer.
However, a spokesperson for Cancer Research UK said it's not definite that there is a link between fizzy drinks and cancer.
Jessica Harris, health information officer at Cancer Research UK, said: 'Although this study included a lot of people, very few of them developed pancreatic cancer so it is difficult to know if soft drinks do increase the risk of pancreatic cancer, or whether the results are just down to chance.
'Also, people who drank lots of fizzy drinks in this study were more likely to be unhealthy in other ways, like smoking, eating more calories, and being less active, so it is difficult to separate the effects of all of these things.
Jessica also said that other studies in this area have been inconsistent - some have shown a link between fizzy drinks and pancreatic cancer, but others haven't.
She said: 'Even so, it's important to remember that people can put on weight if they drink lots of sugary, fizzy drinks and being overweight increases the risk of lots of different types of cancer including bowel cancer and breast cancer.'
Around 7,000 people in the UK get pancreatic cancer each year and it is most common in those over 60. Treatment is far more successful if the illness is caught early.
If you're worried about giving your kids too many fizzy drinks - give some of our smoothies a try instead!
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