Prince Charles and Waitrose have come under fire by health campaigners for the high sugar content in Waitrose's Duchy Organic ice cream.

It has been insinuated that the Prince of Wales' Duchy brand for the food retailer could fuel obesity because it contains nearly twice as much sugar as some other brands. The dessert product was singled out by researchers as an example of the differing levels of sugar in similar foods that appeal to children.

Action on Sugar is urging companies to support Public Health's England's voluntary reformulation programme. It aims to tackle the childhood obesity epidemic which, it claims, is the biggest public health crisis facing Britain.

The survey looked into foods consumed by children, including everyday treats like biscuits and cakes – many of which contained less sugar than Charles and Waitrose's product.

The Duchy Organic vanilla ice cream contains 14.5g of sugar per 100g. Presented in a green box – which suggests it is wholesome and healthy – it was actually found to contain 84% more refined sugar than Asda's 'smart price' vanilla ice cream, with 7.9g sugar.

And if that wasn't enough of a bitter blow to the Prince's brand, the Asda ice cream is also much more affordable at 85p for two litres – compared with £3.49 for every 750ml tub of the Duchy Organic product.

Meanwhile, Organix Goodies Gingerbread Men Biscuits (18.8g sugars per 100g) – contained 38% less sugars than McVitie's Mini Gingerbread Men (30.4g) – which are both aimed specifically at youngsters.

prince charles
Camilla, Duchess of Cornwall and Charles, Prince of Wales in Waitrose, Motcomb Street during their visit to celebrate licensing of Duchy Originals products on September 10, 2009 David Parker/WPA Pool/Getty Images

Action on Sugar's campaign manager Jenny Rosborough said: 'It is quite shocking brands can differ so much in the amount of sugar they put in their products.

"Some people do read the labels, but others are not as health conscious so will not be aware of how much sugar they are giving themselves, and their kids.

"We were in favour of mandatory regulations that would place a maximum limit on sugar levels. At the moment it is voluntary and we are prepared to be proved wrong. But it is clear some manufacturers are doing a better job than others," she added.

Theresa May announced the childhood obesity plan in August of this year, and the campaign group discovered that it encouraged more companies to put less sugar in their best selling products than others. It is now calling on all food manufacturers to follow by example. It claims that reformulation – whereby sugar and sweetness in food items are gradually reduced – is the most important strategy when tackling obesity. It also suggests that the calorie content should be cut.

prince charles
Watch out for the sugar! Prince Charles enjoying a cone ice cream Chris Jackson/Getty Images

On the Waitrose website, the Duchy Organic brand – which was founded by Prince Charles and licensed in 2009 – is described as a "groundbreaking partnership between Duchy Originals and Waitrose." It goes on to state that "it is built on the shared principles of Good Food, Good Farming, and Good Causes set out in our Good Food Charter."

The brand looks like it promotes optimal health with its bright green packaging and the word 'organic' emblazoned in italics on every product. There are over 300 Waitrose Duchy Organic products in the range; these include everyday vegetables and milk to noteworthy ales and biscuits.

A Waitrose spokesman said: "Waitrose Duchy Organic vanilla ice cream is an indulgent product which is not aimed at children." Mail Online reports.

She added: "The sugar content is clearly labelled and we sell a range of vanilla ice creams with a significantly lower sugar content, which our customers can choose if they want a healthier option. Reducing sugar is a top priority and we have an extensive reformulation programme to achieve this, which has already included significantly reducing sugar in chilled juices, cereals, yogurts, soups, cordials and fizzy drinks."

The supermarket added: "Waitrose Duchy Organic is a partnership between Waitrose and Duchy Originals. Waitrose is the owner of the brand licence and is responsible for product formulation under that licensing agreement".

"The Duchy Organic products provide a donation to The Prince of Wales's Charitable Foundation," Rosborough added.

prince charles
Camilla, Duchess of Cornwall and Prince Charles, Prince of Wales pay at the checkout in Waitrose, Motcomb Street during their visit to celebrate licensing of Duchy Originals products David Parker/WPA Pool/Getty Images