His one-man drive against junk food prompted the Government to take action by introducing guidelines on what is served in the canteen and in vending machines.

As a result, catering firms have rewritten their menus and schools in Northamptonshire have been hosting healthy food sessions to show children and parents packed lunch ideas and the benefits of nutritious snacks.

The Health Education Trust charity, which has a branch in Greens Norton, is working along with the Soil Association, Focus on Food and Garden Organic on a Food For Life Partnership to transform school and community food culture across England.

Director Joe Harvey said: "If you look back over the last four years, the changes have been dramatic. There's been a huge shift away from high fat food to more balanced choices, containing more fruit and vegetables and complex carbohydrates such as potato and pasta.

"Chips are available but they have been severely curtailed. The changes have involved the quality of food available to children.

"The food standards set by the Government were brought in September 2006 to get rid of junk food throughout the day, pre-and-post school hours. This included those in vending machines and tuck shops.

"The second phase being introduced next month focuses on nutritional standards and applies to school lunches. It affects primary schools this September and secondary schools the following year.

"This means trying to serve food which meets the nutritional guidelines and is important because for some children, lunch is the probably the main meal of the day."

Cygnet Catering is one of several firms which supply to the county's primary and secondary schools. They have been adapting dishes such as curries, casseroles, pies and jacket potatoes with a host of fillings to meet nutritional guidelines.

Operations director, Hazel Bygate, said: "You have to hit the specifications exactly, such as ensuring a level of zinc in meals served to primary aged children.

"It's found in chickpeas, which isn't popular with children, and also in cheese but you can't include too much because of its high fat content, so another option would be serving wholemeal bread.

"We've also looked at changing our cooking methods, such as steaming vegetables so they don't lose the nutritional value."

Mrs Bygate added: "With rises in the price of food and its transportation to schools because of fuel increasing, we've ended up squeezing our margins.

"We know parents are very conscious of cost. There seems to be a £2 threshold where, if the price goes over, the take-up starts dropping.

"Fortunately, we've managed to keep our costs to around £1.80 to £1.85. If it has increased, it is only by five pence."