Feeding children diets high in calories, fat and sugar could damage their blood vessels by the time they are teenagers, experts say.

A new study funded by the British Heart Foundation (BHF) found that youngsters who had a higher calorie intake, plus more sugar and fat, had stiffer arteries when they were 17 than those whose diets were healthier.

Furthermore, children who ate a Mediterranean-style diet rich in vegetables, fruit, beans and pulses, fish and less meat had less stiff arteries aged 17.

Arteries are key blood vessels which bring oxygen-rich blood from the heart to cells in the body.

Stiffness in the arteries is an important early marker of damage and is caused by a loss of elastic fibres and stiffer collagen fibres in the vessels, increasing the risk of high blood pressure, strokes and heart attacks.

The new study, published in the British Journal of Nutrition, examined data for over 4,700 children from the Avon Longitudinal Study of Parents and Children.

Experts looked at children’s diets from the age of seven and then measured pulse wave velocity – a marker of arterial stiffness – and carotid intima-media thickness in the arteries when they reached age 17.

The results showed that children with diets high in calories, fat and sugar and low in fibre at ages seven and 10, had stiffer arteries aged 17 compared to children who had eaten less calorific, fatty and sugary foods in childhood.

When looking at Mediterranean-style diets, experts also found that children who ate more foods like fish, vegetables, fruit and beans had reduced arterial stiffness at 17.

Consuming anti-inflammatory foods aged 10 (such vegetables and fruit, particularly berries, and a variety of brightly coloured vegetables, as well as nuts, seeds, spices and seafood) also led to less artery stiffness.

Female hands mixing green salad in the bowl (Alamy/PA)
Children who ate a Mediterranean-style diet rich in vegetables, fruit, beans and pulses, fish and less meat had less stiff arteries aged 17 (Alamy/PA)

The experts said every child’s calorie requirement is different and depends on their age, size and how much exercise they do.

But Dr Genevieve Buckland, BHF research fellow at Bristol Medical School, University of Bristol, who led the research, told the PA news agency: “Children will be more likely to get all the nutrients they need and not consume excessive calories if they eat lots of fruit and vegetables, plus high fibre starchy foods like wholegrain bread, and brown pasta and rice, along with lean protein.

“UK dietary guidelines also recommend avoiding high fat and sugary processed foods as much as possible, because they are often calorie-dense and nutrient-poor.”

She added: “Our research highlights the importance of developing well-balanced eating habits from childhood to reduce the risk of future heart problems.”

Dr Sonya Babu-Narayan, associate medical director at the BHF, said: “Cardiovascular disease is the UK’s major cause of disability and premature death and can hit those living in the least well-off areas hardest.

“The results of this study suggest that, to stop heart disease in its tracks, improving people’s diets has to start early and be lifelong.

“A bold and comprehensive approach from Government is needed to ensure the healthy option is the easy option for everyone.

“This includes pushing ahead with delayed laws to curb junk food marketing, and driving industry to reduce the salt and sugar levels in our everyday foods.

“Only then will we give children the opportunity to live a long and healthy life, no matter where they live.”

It comes as a separate study in the journal Atherosclerosis noted that high cholesterol levels in adolescence can cause structural and functional damage leading to premature heart damage and death.

The study, from the University of Exeter, University of Bristol and the University of Eastern Finland, suggested earlier checks for children could prevent future heart problems.

The research found elevated cholesterol and dyslipidaemia (an imbalance of lipids in the blood, including cholesterol) in children and adolescents increased the risk of premature death by the mid-40s and other heart issues in the mid-20s.