Why diet carbonated drinks may be worse than full-sugar ones

Brits spent £2.5 billion on Pepsi and Coke last year, according to The Grocer. But almost all fizzy drinks are ultra-processed and are one of the worst products you can consume for your overall health.

They contain almost no whole foods at all – they’re almost entirely chemical ingredients – and are artificially coloured and sweetened. One study in The Lancet last year which investigated UPFs named soft drinks alongside processed meat as products that are most significantly associated with cancer, diabetes and heart disease.

Pepsi Max, one of the most popular soft drinks sold in the UK, contains artificial colours, two sweeteners, acids, flavourings and potassium sorbate as a preservative. The only ‘normal’ ingredient is carbonated water.

Energy drinks, which are hugely popular, are even worse. A 250 ml can of Red Bull contains almost six teaspoons of sugar, along with caffeine, flavourings, colours and acidity regulators.

Prof Gunter Kuhnle says, “The interesting thing is that, in observational studies, people who consume the diet versions appear to be at greatest risk of disease and weight gain.”

While drinks like diet Coke and Pepsi Max may not contain too many calories and make you put on weight in themselves, there’s something more complex going on.

“Perhaps people who drink them have a worse diet overall, or they may think because they’re drinking diet versions they can eat more hamburgers at the same time.”

Although they will have still undergone some processing, experts say that sparkling natural mineral water – or carbonated fruit juice – is ‘probably not UPF’ as long as it doesn’t contain any other flavourings or sweeteners.

“The best approach, if you do want flavour in your drink, is to add fresh fruit to unsweetened sparkling water,” says Prof Kuhnle.