How healthy is your favourite iced coffee? Top dietitian reveals the high street's best - and the worst offenders

When temperatures climb, many ditch their usual steaming hot coffee for its icy equivalent.

From iced lattes to syrup-soaked frappes and indulgent ‘Spanish’ coffees made with a splash of condensed milk, high street chains are brimming with tempting options. 

But not only do they promise to bring some temporary refreshment from feeling hot and bothered, some of these seasonal favourites - which look more like desserts than drinks - are also packing serious amounts of sugar, fat and calories. 

Our growing thirst for iced barista-made drinks has been fuelled in part by celebrities such as Taylor Swift, Ben Affleck, Britney Spears and Khloé Kardashian, who are regularly photographed clutching oversized iced coffees.

But your refreshing caffeine fix could be hiding a worrying secret.

A Which? investigation found that several popular iced coffees sold in major chains contain more sugar than the recommended daily limit in just one cup.

So just how unhealthy are these summer favourites?

We asked Nichola Ludlam-Raine, specialist dietitian and author of How Not to Eat Ultra-Processed, to reveal the worst offenders, from worst to best...

Caffè Nero Espresso & Caramel Luxury Frappe 

Caffè Nero describes this popular seasonal menu item as a 'creamy whipped iced frappe made with caramel sauce and classico espresso, topped with whipped cream and a drizzle of caramel'. 

But according to Ms Ludlam-Raine, it contains enough calories to rival a light meal and a 'considerable' amount of sugar and fat.

Nutritional info (per serving):

Caffeine: 160mg

Calories: 469kcal

Sugar: 53.4g

Fat: 21.2 g

'Once a drink starts containing large amounts of syrup, whipped toppings, sauces and sweetened foams, it becomes much closer to a dessert than a coffee,' Ms Ludlam-Raine says.

'There's nothing wrong with enjoying one occasionally- no more than monthly perhaps - but it sits firmly in the "treat" category rather than as an everyday coffee choice.'

Ms Ludlam-Raine's rating: 1/5  

Starbucks Iced White Chocolate Mocha

Starbucks describes this drink as a mixture of espresso, milk, and white chocolate-flavoured sauce, poured over ice and topped with whipped cream.

Ms Ludlam-Raine points out that the white chocolate sauce significantly increases both the sugar and fat content, of which most of it is saturated - 'the fat type that many of us should be consuming less of'.

Nutritional info (per serving):

Caffeine: 89.1mg

Calories: 401kcal

Sugar: 45.7g

Fat: 19.1g

Our expert says: 'While it can indeed be enjoyed as an occasional treat, it's probably best viewed in the same category as a dessert rather than a standard coffee order.'

Ms Ludlam-Raine's rating: 1.5/5  

Starbucks Brown Sugar Cloud Frappuccino

Nutritional info (per serving):

Caffeine: 27.7mg

Calories: 319kcal

Sugar: 37.2g

Fat: 16g

Our expert says: 'Although marketed as a coffee drink, nutritionally it's closer to a dessert/sugary milkshake. 

'It contains relatively little caffeine compared with most coffees, meaning you're getting much more of the sweetness and indulgence than the coffee itself.'

Ms Ludlam-Raine's rating: 2/5

Generic iced caramel latte

Nutritional info (per serving):

Caffeine: 75 to 150mg

Calories: 190 to 290kcal

Sugar: 24g to 44g

Fat: 5g to 9g

Our expert says: 'This category varies enormously between coffee shops. Some versions are relatively moderate, while others contain large amounts of syrup and added sugar. 

'If caramel is your favourite flavour, asking for fewer pumps of syrup can make a substantial difference (or ask for a sugar-free syrup).'

Ms Ludlam-Raine's rating: 2.5/5

Costa Spanish Iced Latte

Nutritional info (per serving):

Caffeine: 184 mg

Calories: 225kcal

Sugar: 29g

Fat: 4.7g

Our expert says: 'This sits somewhere in the middle. It delivers one of the highest caffeine levels on the list but also contains a significant amount of sugar.

'However, most of the sugar will be naturally occurring from the milk (19g of the 29g - but that's still 2 tsp of added sugar per drink or 10g, which is a third of our daily allowance.

'It's a reasonable occasional choice but probably not one for every day.'

Ms Ludlam-Raine's rating: 3/5 

Pret Iced Blueberry Latte

Nutritional info (per serving):

Caffeine: 180mg

Calories: 147kcal

Sugar: 21.7g

Fat: 3.6g

Our expert says: 'The blueberry flavour makes this a more interesting choice but don't assume that fruity automatically means healthier. 

'It's still a relatively sweet drink, although it compares favourably with many frappé-style alternatives.'

Ms Ludlam-Raine's rating: 3.5/5 

Caffè Nero Iced Brown Sugar Oat Latte

Nutritional info (per serving):

Caffeine: 160mg

Calories: 136kcal

Sugar: 18.6g

Fat: 3.2g

Our expert says: 'While sweeter than the top two, it's still more balanced than many flavoured iced coffees on the market and remains recognisably a coffee rather than a treat drink.'

Ms Ludlam-Raine's rating: 4/5 

Caffè Nero Iced Honey Foamed Americano

Nutritional info (per serving):

Caffeine: 160mg

Calories: 67kcal

Sugar: 13.3g

Fat: 0.4g

Our expert says: 'A good choice for those who enjoy a sweeter coffee but don't want lots of added syrups, cream or excess calories. The honey foam adds sweetness while the drink itself remains relatively light.'

Ms Ludlam-Raine's rating: 4.5/5 

Best option: Costa Iced Oat Velvetino

Nutritional info (per serving, small 255ml):

Caffeine: 185 mg

Calories: 91kcal

Sugar: 9.4g

Fat: 3g

Our expert says: 'This was the standout option overall. 

'It offers the flavour and enjoyment of an iced coffee while keeping calories, sugar and fat relatively modest - and as a bonus, the fat is mainly unsaturated (as it's plant-based), as opposed to saturated. 

'It still delivers a substantial caffeine hit too, making it feel much more like a coffee than a dessert.'

Ms Ludlam-Raine's rating: 5/5 

The verdict

Many of these iced coffees can contain around 160–185mg caffeine per serving, which is similar to - or even higher than - some regular coffees. 

For most healthy adults, the recommended maximum caffeine intake is around 400mg per day, while pregnant and breastfeeding women are advised to limit caffeine to 200mg per day. 

This means that just one large iced coffee could provide close to half of an adult's daily caffeine limit, and in some cases, almost all of the recommended limit during pregnancy. 

Ms Ludlam-Raine highlights that the biggest nutritional divide isn't between coffee chains - it's between iced coffees and frappé-style drinks. 

'The best everyday choices tended to be those that kept added sugars and extras to a minimum, while still allowing the coffee itself to shine through,' she says.

'My advice would be to enjoy the more indulgent options if you love them, but think of them as occasional treats rather than daily staples. 

'For everyday drinking, choosing a simpler iced coffee and customising the sweetness to your taste can make a big difference.'