Celebrity nutritionist reveals one drink she urges her clients to stay clear of

An expert nutritionist has revealed the one drink she urges all her clients to stay away from.

Sarah Carolides is University of Cambridge-educated, and is seen as one of the UK's foremost experts in functional medicine and nutrition — so it's safe to say we should all be following any advice she gives.

One example that Sarah says she tells all her clients to do is drink lots of water.

"I will get so many clients that come to me and they literally have like, one glass of water a day," she told UNILAD.

"They might have a few coffees and teas, but there's just no water."

The nutritionist highlighted the importance of drinking water (Getty Stock)

If you're unsure what real benefits drinking more water can have on you and your body then don't worry; Sarah has revealed all.

She explained: "Your energy goes up, your skin improves. You sleep better. Absolutely everything starts to move when you get your hydration right."

With this in mind, Sarah often challenges her clients – who include some celebrities — to try and drink three liters of water a day for a week.

While we should be drinking lots of water, what shouldn't we be drinking, according to Sarah?

It will probably come as no surprise to you that the expert nutritionist immediately said Diet Coke when presented with this question.

Sarah Carolides is a celebrity nutritionist (Supplied)

Divulging why, Sarah, who is the Head of Nutrition at Zooki, told us: "The second ingredient of Diet Coke is called phosphoric acid, and that gets straight into your bloodstream and causes the pH of the blood to drop because it's acidic.

"The blood then has to make it more alkaline again, so there is evidence that it interferes with calcium absorption, because calcium is a big fat alkaline molecule."

Further explaining the science of it all, Sarah went on: "The blood gets that back, stops it going into the bones to neutralize that acid that's just come in from those fizzy drinks."

Dark fizzy drinks like cola often have phosphoric acid in them (Getty Stock)

In simpler terms, it's believed that Diet Coke makes your blood more acidic, which can negatively affect bone density and calcium absorption.

This was highlighted in a 2006 study published in the National Library of Medicine which found that cola consumption specifically was associated with significantly lower bone mineral density (BMD) at the hip joint and the hip bone in women.

Similar results were seen for diet cola as well.

"No significant relations between noncola carbonated beverage consumption and BMD were observed," the study added.

It should be noted that not all fizzy drinks have phosphoric acid in them (which gives them their tangy flavor).

The controversial ingredient is typically found dark-colored soft drinks like cola.

Sarah suggested that CBD-infused drinks from TRIP could be a healthier alternative to fizzy drinks like Diet Coke.