The hugely popular energy drink, Prime Energy, is under scrutiny for its eye-popping caffeine levels – with health experts in the US the latest to call for the product to be banned. A 12oz (330ml) can of Prime contains 140mg of caffeine, the equivalent of nearly six cans of Coke and almost twice as much as Red Bull. Prime is already banned in British and Australian schools due to concerns about heart problems, anxiety and digestive issues in children. 

The brand's first product, Prime Hydration, is a caffeine-free, zero-sugar, vegan sports drink sold in six different flavours. The colourful bottles sparked a frenzy upon their launch, with long queues at shops and people even selling them on at hiked-up prices. The high-caffeine Prime Energy was launched later and targeted explicitly at adults, but the damage – according to those calling for the ban – was done. The caffeinated neon-coloured cans, they argue, are as appealing to young audiences as the bottles. 

The brand, founded by YouTube stars Logan Paul and KSI (pictured), has defended Prime Energy, stating it's clearly labelled as 'not recommended for children under 18'. However, US Democratic Senator Chuck Schumer has recently argued that the marketing for both drinks is too similar, potentially misleading parents about the product and making the energy drink appealing to younger people. He has urged the Food and Drug Administration (FDA) to investigate Prime's controversial energy drink's advertising, ingredients and caffeine content.

Concerned about caffeine levels? Read on to discover the surprisingly high-caffeine food and drink that could affect your sleep:

For many of us, a morning caffeine fix is routine. Around 62% of Americans drink coffee daily, while Brits collectively glug 98 million coffees each day. Coffee beans are a natural source of caffeine, a central nervous system stimulant, and the US health authorities suggest adults shouldn’t consume more than 400mg of caffeine per day (roughly four to five cups of coffee) as more can cause insomnia, anxiousness and an increased heart rate. We've rounded up the surprisingly high-caffeine food and drink beyond coffee.

Surprisingly, decaf actually does contain some caffeine. The decaffeination process removes around 97%, leaving around 2mg in the average cup of decaf. Moderate amounts can actually be beneficial, according to Dr Simoné Laubscher, formulator of WelleCo’s nutritional supplements and founder of Rejuv Wellness. “Coffee is rich in antioxidants plus micronutrients, such as magnesium – and decaffeinated coffee has similar health benefits,” she explains.

A thirst-quenching 100 million cuppas are consumed each day in Britain, making black tea among the most consumed drinks in the world. Tea contains flavonoid antioxidants, which could have positive health effects and reduce the risk of disease. It also, of course, contains caffeine. A typical mug of tea has around 14-61mg of caffeine, depending on how long you let it brew. On average, a cuppa has around 47mg of caffeine.

The percentage of cocoa solids in your chocolate determines its caffeine levels. As a guide, a 3.5oz (100g) serving of milk chocolate has around 21mg while the equivalent amount of dark chocolate (70-85% solids) has 80mg. White chocolate, which contains only cocoa butter and no solids, is caffeine-free. "Natural caffeine foods often offer health benefits artificially added caffeine foods don’t. For example, dark chocolate is rich in fibre, iron, copper, manganese and antioxidants," says Dr Laubscher.

Some flavoured waters contain 60-125mg of caffeine per bottle (254ml/8.5 fl oz), particularly those marketed as caffeinated waters designed to give an energy boost. Dr Laubscher believes they should be approached with caution. "I’d suggest limiting daily intake of flavoured water, especially as these products are synthetic," she says.

Grab-and-go bars with nuts, seeds and dried fruit are popular for snacks and quick breakfasts. They also can often contain sweeteners and hidden additives – including caffeine. In some cases, the latter is a selling point for bars marketed as pre-workout boosters. But exact amounts aren't always disclosed on the label and it varies wildly from minimal amounts to – in the case of one bar sold in the US – as much as 350mg in a single serving.

Green tea contains powerful antioxidant EGCG and nutritionists believe it could boost brain function and protect against disease. It does also contain caffeine, though in smaller quantities than coffee and the average cup of brewed black tea. As with the latter, the amount depends on the individual leaves and how long the tea is brewed for, typically it's somewhere between 35-80mg per cup.

Many ice creams contain zero caffeine, being essentially frozen custard, but it all depends on the flavour. Chocolate or coffee varieties will almost certainly contain some caffeine unless the flavourings are entirely artificial. The US Department of Agriculture (USDA) states that 3.5oz (100g) of chocolate ice cream has around 3mg of caffeine. Figures from 2015 show that Ben & Jerry's Coffee Toffee Bar Crunch ice cream contained 70 mg caffeine per 8oz (236g).

Most breakfast cereals contain zero caffeine, though those that contain chocolate or cocoa tend to have small amounts. Cocoa Puffs and Coco Pops (Cocoa Krispies in the US), for example, contain around 1.6mg of caffeine per 1oz (28g), which is the equivalent of a small serving. Not a huge amount but something to be aware of if you tend to overfill the bowl.

A large Americano (around 473ml/16fl oz) contains around 225mg caffeine while the same size energy drink can have up to 357mg, which is edging very close to the 400mg recommended daily safe limit. Many energy drinks are sold in bottles twice this size too. "Having multiple energy drinks daily could quickly put you over the caffeine limit, increasing health risks like higher blood pressure and heart rate," says Dr Laubscher.

There's unlikely to be any caffeine lurking in a packet of plain biscuits or an oatmeal and raisin cookie but choc-chip treats are another matter. An individual cookie (roughly 1oz/28g) made with milk chocolate chips contains around 3-5mg of caffeine – a tiny amount but something to bear in mind if you eat them before going to bed or are tempted to mainline an entire packet. Biscuits containing or coated with dark chocolate will be higher in caffeine content too – and, of course, varieties with coffee will have more still.

Beer doesn't naturally contain caffeine but the trend of rich, creamy stouts and porters brewed with coffee beans or cold-pressed coffee means that pint or schooner could pack a bit more of a punch than expected. Many breweries, big and small, around the globe are experimenting with the rich, smoky flavours brought by coffee. Because it's relatively new and brews vary wildly it's hard to pinpoint the caffeine content of an average coffee-flavoured beer, though website Caffeine Informer reckons it's probably less than 50mg per 350ml (11.8fl oz) pour.

Yerba maté is made using the dried leaves of a holly found in the South American rainforest and has long been a popular drink in the region, usually sipped with a straw from a distinctive gourd or calabash. It’s increasingly popular outside South America too, partly because it’s believed to have certain health benefits. However, it does have a surprising amount of caffeine, packing in more by volume than the average coffee – yerba maté has around 78mg per 150ml (5fl oz) serving.

Yep, caffeinated gum is a thing, designed to give a quick burst of energy. Research suggests that caffeine is absorbed more quickly through the inside of your mouth than through your digestive system. But Dr Laubscher warns that people should chew with caution, as one piece can contain up to 100mg of caffeine. "Moderation is key as it's easy to consume too much caffeine from them. Plus, over-chewing increases stomach acid, which could lead to stomach ulcers."

Originally getting its caffeine kick (and its name) from the kola nut, Coca-Cola's balance of sweet and bitter flavours has made it one of the world's most popular drinks. It does contain caffeine (with caffeine-free varieties available), though less than the average cup of tea or coffee. A regular (330ml/11fl oz) can of Coca-Cola and Coca-Cola Zero Sugar both contain 32mg caffeine, while surprisingly Diet Coke has a little more at 42mg.

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Coca-Cola isn't the only fizzy drink to contain a significant amount of caffeine. Surprisingly, a glass of orange soda can also have the stimulant, depending on the brand. Sunkist has 19mg of caffeine per regular can, though Fanta has none at all. Another popular drink that contains caffeine is Mountain Dew, with 55mg in a 340ml (11.5fl oz) bottle.

Almost any processed food can be caffeinated. Raw nuts don’t naturally contain caffeine but the stimulant can crop up in the seasoning, like in these mocha-flavoured almonds.  A 1.8oz (51g) pack of peanut butter cups also has caffeine thanks to the chocolate, though it's a minimal 5.6mg.

It would be easy to assume that coffee yogurt contains artificial flavouring rather than actual coffee, therefore making it free from caffeine. But it tends to be the real stuff that's used, with a Danone coffee yogurt containing 32mg in 150ml (5fl oz). Coffee-flavoured frozen yogurt also, like ice cream, usually contains some caffeine.

A steaming mug of cocoa or hot chocolate has long been a favourite bedtime drink for many but the caffeine it contains could interrupt sleep patterns, especially if you're particularly sensitive to the stimulant. A hot chocolate drink at Tim Hortons varies from 15-35mg, depending on the size, while any made with real chocolate flakes (especially where there's a high proportion of cocoa solids) will be more potent, with as much as 25mg in a café-bought cup.

Studies have shown that mixing alcohol with high-caffeine drinks can have health implications and lead to a higher risk of alcohol-related incidents and dependency. Because of this, pre-mixed alcoholic drinks that have been artificially caffeinated to give an extra kick have been banned in the US. That doesn't stop people from mixing their own though. Dr Laubscher warns this can be a too-potent cocktail: "Mixing alcohol and caffeinated drinks can have negative effects on your liver and nervous system, leaving you in high stress fight-or-flight mode, increasing cortisol and belly fat."

This rich, creamy trifle is an Italian classic that you'll often find on restaurant menus. As you're more likely to eat it in the evening and perhaps with a coffee, it's worth bearing in mind that – as this is a coffee-flavoured dessert – it does contain some caffeine. No wonder it translates as 'pick me up' from Italian.

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Homemade iced tea follows the same principles as hot black tea – the amount of caffeine it contains depends on the tea used and how long it's allowed to brew, so it can have between 14-61mg of caffeine per serving. Shop-bought iced teas, like those made by Lipton, vary too but the brand's popular lemon-flavoured iced tea has 21mg in a 500ml (17fl oz) bottle. That could add up to a lot, particularly in the US where many diners and cafés offer bottomless top-ups of iced tea.

Formulated to boost energy before exercise, pre-workout drinks – whether pre-mixed or sold as powders – usually contain caffeine. The amount varies wildly depending on the brand and variety but some hover worryingly close to the recommended daily intake limit. Men's Health cites an example of a powder with 410mg of caffeine per quarter ounce (7.5g) scoop, which is just above the recommended maximum.

It sounds like a no-brainer – snacking on coffee beans is bound to up your caffeine intake. What might be surprising, though, is just how much caffeine they contain. The potent combination of coffee and dark chocolate makes these among the foods with the highest levels of caffeine per serving, if not the highest. Nutritionist Daisy Whitbread, analysing data from the USDA, suggests a 1oz (28g) serving – roughly 28 beans – has a whopping 336mg of caffeine.

Another deceptive one, which you might think gets its coffee taste from flavouring, coffee liqueur can be a high-caffeine drink depending on the quantities you consume. A 40ml (1.3 fl oz) shot has around 14mg of caffeine, which isn’t much in itself but could quickly add up. Especially if you’re a fan of espresso martinis. These cocktails give a double caffeine dose with espresso and coffee liqueur, adding up to an average total of 78mg per serving (more if they’re made with more booze and/or coffee).

This naturally effervescent fermented tea has become hugely popular with many people believing it has certain health benefits. It’s pretty impossible to make it caffeine-free though, because the SCOBY – a colony of bacteria and yeast that makes the drink – needs caffeine and sugar to do its job and traces are left after fermentation. A serving typically has around a third of the caffeine of a cup of tea, between 10-25mg.

As with choc-chip cookies and other similar treats, the amount of caffeine in a slice of chocolate cake very much depends on the type of chocolate used and how much goes into the bake. A cake rich in dark chocolate will, for example, contain significantly more caffeine than a plain sponge with a chocolate frosting or ganache and a white chocolate cake will have no caffeine at all.

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