The high street coffee shops with the most caffeine in their cups revealed

A new study has found that high street coffee chains have “huge” differences in the amount of caffeine served in popular drinks.

A medium cappuccino at Costa Coffee contains a “massive” 325mg of caffeine, almost five times the strength of the Starbucks version with a modest 66mg.

By contrast, Greggs and Pret A Manger also use significantly less caffeine in a cappuccino of the same size, at 197mg and 180mg respectively. Caffè Nero had the second lowest levels of caffeine after Starbucks in this drink specifically, containing between 110mg and 115mg.

The study also found that one single espresso from Pret A Manger contains 180mg of caffeine, or six times as much as its Starbucks counterpart. Pret’s filter coffee also contained the highest caffeine levels at 271mg, compared to 225mg at Greggs and 102mg at Starbucks.

The variations aren’t solely caused by the number of caffeine shots used. The two main types of coffee bean – Arabica and Robusta – have differing caffeine amounts as well as variations in tastes, with Arabica containing approximately half the quantity of caffeine.

With such a large disparity from one chain to another, customers have little idea how much caffeine they’re consuming. This can cause problems for people who are sensitive to caffeine, pregnant people or patients on certain stimulant medications.

The maximum recommended caffeine allowance is up 400mg per day. Pregnant people are advised to consume no more than 200mg, and children no more than between 45mg and 100mg per day.

Elsewhere, certain medications used to treat ADHD – Attention Deficit Hyperactivity Disorder – advise that patients should avoid overconsuming caffeine and regulate their consumption.

One cup of tea or coffee combined with ADHD medications like methylphenidate or dexamfetamine may not do any harm, but overdoing it with large amounts of caffeine can be dangerous, and can cause overstimulation, heart palpitations or insomnia.

Which? nutritionist Shefalee Loth told PA: “Many of us rely on coffee to get us through the dark winter mornings, but our research shows you may be consuming significantly more, or less, caffeine than you bargained for.

“Our analysis has shown that there are big variations in caffeine content between drinks from different high-street coffee shops.

“Most of the time this shouldn’t be an issue but if you drink a lot of coffee or need to limit your caffeine intake you might want to consider what you’re ordering and where from.”

A Costa Coffee spokeswoman said: “The amount of caffeine included within each coffee varies, depending on both the coffee and size of drink ordered by a customer.

“All Costa coffees can be enjoyed with decaf coffee and we offer a wide range of non-caffeinated drinks including the FuzeTea Superfuzions range.

“All caffeine information is available both in our store or via our website and we would encourage customers to be aware of the caffeine content in their favourite Costa coffee to ensure it is right for their dietary requirements or lifestyle choice.”