Taxing cakes, biscuits and sweets could tackle obesity and lead to people in the UK losing 2.8lbs (1.3kg) a year, a study has claimed.

Researchers say slapping a 20 per cent tariff on the sugary snacks could be more effective than the current fizzy drinks tax.

Campaigners have already called for the broader 'calorie tax' to add to the price increase on drinks, adding that targeting sugar on its own isn't enough.

Figures show a quarter of people in the UK are now obese, meaning they're at a greater risk of cancer, heart disease and stroke.

In a study published in the British Medical Journal, scientists predicted the average family could eat almost 9,000 fewer calories each year if the prices of their favourite treats were inflated.

And this, they claimed, could cut the country's obesity rate by as much as 2.7 per cent, bringing around 446,000 people back to a healthy weight within a year.

A 20 per cent price rise like the one suggested by the researchers could help to reduce obesity by pricing people out of buying as many unhealthy snacks as they do now, the study claimed. The products pictured are examples only, and are not mentioned in the BMJ study – prices were taken from the Tesco website on September 4, 2019

Researchers led by the London School of Hygiene and Tropical Medicine (LSHTM) looked at grocery shopping habits of families in the UK.

Their concept of a 20 per cent price increase on high-sugar snacks could push the price of a pack of 10 Cadbury Mini Rolls from £2.50 to £3.

A 200g bar of Dairy Milk chocolate could rise from £2 to £2.40, or a bag of Haribo Starmix from £1.25 to £1.50, based on Tesco prices.

The team said the option was 'worthy of further research' as the Government continues to look for new ways to curb obesity, particularly in children.

'The UK has a unique profile when it comes to free sugar intake,' said the study author Dr Pauline Scheelbeek, a health researcher at LSHTM.

'Unlike many other countries, the amount of calories consumed through high-sugar snacks is on average much higher than those consumed through sugar-sweetened beverages.

'Our work found that price increases in high-sweet snacks such as chocolates, confectionary, cookies and cake could therefore lead to much larger health gains in the UK than similar price increases in sugar-sweetened beverages.'

WHAT IS THE SUGAR TAX? From April 2018, soft drinks companies have been required to pay a levy on drinks with added sugar. If a drink contains between 5g and 8g of sugar per 100ml the tax is 18p per litre, whereas if a drink has more than 8g of sugar per 100ml, the tax is 24p. Fruit juices and milk are not included in the tax. The move aims to help tackle childhood obesity. Sugar-sweetened soft drinks are now the single biggest source of dietary sugar for children and teenagers. Some drinks, including Fanta, Lucozade, Sprite, Dr Pepper and Vimto, had their recipes changed so they contained less than 5g of sugar and the price did not need to be put up. However, others like Coca Cola and Pepsi refused to reduce the amount of sugar and, as a result, the price of them increased. The Government has predicted the levy will raise £240million a year, which will be spent on sports clubs and breakfast clubs in schools. The sugar tax raised £153.8m in the first six months after it was introduced, between April and October 2018. Advertisement

Dr Scheelbeek's team studied how much money 36,324 British households spent on certain categories of foods using data from a two-year long consumer survey.

They worked out how many calories people would get from a certain amount of money spent on snacks, then estimated how this would change if the price rose.

If a family spent £10 on sweets, for example, and the price of sweets went up by 20 per cent, they would only get as many sweets as they could have bought for £8.33 beforehand.

This effectively prices people out of overeating and leads to them eating less sugar and fewer calories because they can't afford as much food as before.

Low-income households in which people are already overweight would be most dramatically affected by the price change, the researchers estimated.

Price inflation could lead them to eat 4,805 fewer calories from chocolate and sweets, and 3,709 fewer from biscuits.

Wealthier families appeared to make different shopping choices – middle-income households (£20,000 to £49,999 per year) would stand to lose 4,395kcal from biscuits, while the wealthiest homes were hardest hit in the cake department, with predicted losses of 4,182kcal per year.

And overweight middle-income households were likely to lose the most weight, with an average 4.6lbs (2.1kg) over a year.

Low-income households were predicted to lose 2lbs (911g) over the year, lowerbecause they may be more likely to compensate with other unhealthy foods.

Dr J Bernadette Moore, an obesity expert at the University of Leeds, wrote in a comment in the journal: 'Substitution and displacement effects in response to food tax and subsidy policies are complicated and difficult to predict.

'The reformulation of products in response to consumer demand can also have unintended consequences, such as substituting one unhealthy ingredient for another.

'Lastly, fiscal policies aimed at reducing consumption of sugar, salt, and saturated fat might be useful, but they fail to incentivise the consumption of healthy foods.

'Ultimately, tackling obesity and diet related disease requires close scrutiny of the social determinants of food environments and a systemic, sustained group of initiatives aimed at reducing health inequalities.'

Dr Moore added that the 20 per cent suggested in Dr Scheelbeek's study was particularly high, claiming that other 'sin taxes' are typically lower than 10 per cent.

And the researchers themselves said their research could be flawed by people eating unhealthily outside of the home, or by the calorie intake to weight loss equation not being a perfect representation of how people gain and lose fat.

The LHSTM team's research comes after campaign groups Action on Sugar and Action on Salt called for a calorie tax to be introduced by the UK Government.

They didn't suggest a specific charge, as the London team did in their study, but said in August: 'If you want people to make healthier choices, you have to hit them in the pocket where it hurts.'

In light of today's research, Holly Gabriel, a nutritionist at Action on Sugar said: 'The UK Soft Drinks Industry Levy has been remarkable and unique in that it allows for significant product reformulation by manufacturers in order to avoid paying the levy.

'This has already resulted in a much bigger reduction of sugar content of drinks in the UK than originally anticipated.

'Fat is a bigger contributor to calories in the diet than sugar and therefore essential that manufacturers are encouraged to reduce both in order to tackle the UK’s obesity crisis.'