The five foods doctors think kids should never eat

Brightly coloured slush drinks have long been a popular treat for children across the UK. However, this week, researchers at University College Dublin revealed that they are far more dangerous than they seem.

They examined the cases of 21 children aged between two and seven across the UK and Ireland who needed emergency treatment shortly after drinking a slushie. Most of the children lost consciousness and showed signs of low sugar and high acidity in their blood, four needed brain scans, and one even had a seizure.

The culprit? A naturally occurring sweetener called glycerol which is used instead of sugar to keep the brightly coloured drink from freezing solid and give it a “slushie” texture.

Current Food Standards Agency (FSA) advice says under-fives should avoid the drinks and under-11s should have no more than one. However, medics believe children should not be allowed to drink a slushie until they are at least eight years old.

“There’s no transparency around how much glycerol is used in these drinks – it’s very hard to find out that information,” explains Prof Ellen Crushell, a metabolic paediatrician and lead author of the study which was published in Archives of Disease in Childhood.

Glycerol is added to various ultra-processed food products to improve texture, increase moisture, and enhance sweetness without the need for excessive sugar.

It is often found in small quantities in common products such as tortilla wraps, cereal bars, and cake icing.

However, whilst small doses of glycerol are deemed safe, the quantity in a single slushie could be dangerous for young children and result in “glycerol intoxication”, says Prof Crushell.

The colourful beverages are the latest in a long line of allegedly child-friendly foods that experts believe are dangerous for young people.

Whether it’s because of their high sugar content, long list of additives, or unhealthy fats, here are five foods nutritionists and doctors believe children should never eat – and what to have instead.

1. Slushies

At school fairs parents have been known to refer to slushies as “children’s crack” such is their popularity. Typically made of ice, syrup, and sweeteners kids have been slurping them since the 1970s but it’s only recently that the dangers have become so vividly apparent. The problematic ingredient in slushies is glycerol.

Used as an alternative to sugar, Prof Crushell, explains that “if you give a child a large dose of glycerol their metabolism can’t cope with it. It interferes with glucose metabolism in a child’s body, causing a drop in blood sugar levels which can result in hypoglycaemia and loss of consciousness”. She adds that it can also lead to nausea and headaches so there’s likely a “milder cohort” of children who have been affected after drinking a slushie despite not needing hospital treatment.

The healthy swap

Rhiannon Lambert, a nutritionist and founder of Rhitrition, recommends replacing slushies with homemade smoothies using whole fruits like bananas and strawberries with some milk. “These provide fibre, vitamins, and natural sweetness without the risk of glycerol or excessive sugars,” she explains.

2. Cereal bars

At first glance, they seem fairly innocuous. However, Diabetes UK points out that most popular cereal bars are shockingly high in sugar. For example, Nature Valley Oats and Honey contains 11.3g of sugar per serving – 13 per cent of our daily allowance.

More worryingly, they’re marketed as healthy, yet contain refined grains, unhealthy fats as well as huge amounts of sugar. Refined grains are processed to remove the bran and germ which makes them finer and longer lasting, but less nutritious than whole grains. It strips them of nutrients including B vitamins, iron, and dietary fibre. Many cereal bars, especially those marketed to children, may also contain glycerol as a humectant to keep them moist and prevent them from becoming dry or crumbly, Lambert explains.

The healthy swap

Porridge oats or low-sugar wholegrain cereals like Weetabix or Shredded Wheat provide a high-fibre alternative to breakfast bars. They offer sustained energy “which helps stabilise blood sugar and promote fullness, supporting concentration and energy throughout the day”, Lambert says.

3. Gummy sweets

An inherent preference for sweetness is hardwired into human behaviour, making sweets an irresistible choice for children. Whether it’s fizzy Cola bottles or juicy cherries, the average UK child consumes around 208 bags of sweets a year, according to a 2020 study. 

“Gummy sweets are essentially pure sugar and consuming these frequently can spike blood sugar levels, leading to energy crashes shortly after,” Lambert explains. Over time, high-sugar diets can increase the risk of childhood obesity, Type 2 diabetes, and poor oral health. Young children can also experience negative effects on their mood, behaviour, and focus as a result of blood sugar spikes.

The healthy swap

Try dried or fresh fruits which naturally contain sugars but are also rich in other vitamins, nutrients, and fibre. “These help to moderate the release of sugar into the bloodstream and keep children feeling fuller for longer,” Lambert explains.

4. Flavoured yogurts

Flavoured yogurts are a lunch box staple for children in the UK. However, whilst brands often boast of their low-fat content, they stay conspicuously quiet about their high sugar levels. Again this seemingly healthy food is full of hidden sugars that can contribute to child obesity, tooth decay, and other health problems. To be classed as “low sugar” and earn a green label on their packaging, food products must contain a maximum of 5g of sugar per 100g. However, research conducted by the charity Action on Sugar in 2021 found that nearly two-thirds of the yogurts marketed at children provide at least a third of a four-to six-year-old’s maximum daily intake of added sugars, while only one in 20 of yogurts with child-friendly packaging contain low levels (green) of sugar.

The healthy swap

Opt for plain Greek yogurt and add fresh or mashed fruit for natural sweetness. Lambert says Greek yogurt is rich in protein and is a probiotic, meaning it can support gut health. Food which is naturally high in protein can also help to keep children fuller for longer and aid growth and development.

5. Marshmallows

Sugar, gelatin, and corn syrup doesn’t necessarily sound like the makings of a delicious sweet treat, however marshmallows have retained their popularity over the years – whether consumed straight from the packet, or roasted above a bonfire and sandwiched between two chocolate biscuits.

Sugar is, once again, the key culprit. “Marshmallows are nearly 100 per cent sugar, with no nutritional value. They promote tooth decay as they stick to teeth and provide a rapid sugar release into the blood that can lead to energy crashes shortly after,” Lambert explains. The NHS recommends children aged four to six should have no more than 19g of free sugars (sugars added to food or drinks, and sugars found naturally in honey, syrups, and unsweetened juices) a day. A single serving of four large marshmallows provides around 23g of sugar.

The healthy swap

Replace marshmallows with natural sweet treats such as fruit skewers or homemade frozen yogurt with fruit. “These can satisfy a sweet craving while providing vitamins, minerals, fibre, and protein,” Lambert explains.