A new $5.3 million (pound;3m) computer system to be phased in across America’s seventh-largest education authority, next school year, will allow parents to put blocks on menu items they do not want their children to order and limit them to a single helping.

Parents will be able to log on to a website to pay for school dinners in advance. Pupils will receive an account number that they can key in at consoles in school cafeterias to pay for their meals. The system captures the menu items they choose, feeding them back to the website so parents can keep tabs on their child’s eating habits.

If they do not like what they see, parents can contact the school to flag certain foodstuffs as off-limits, said Ray Barger, director of sales and marketing at Houston’s Cybersoft Technologies, the system’s manufacturer.

If a pupil subsequently tries to order any illicit items, cafeteria staff will be informed by a message flashing up on their cash registers. “If they continue to try to sell the product they will get a longer message on their screen,” said Mr Barger.

The system has already been installed at other schools in Texas, as well as some in Arizona, Michigan, Oklahoma and Tennessee, he said.

But Houston, with 305 schools and 200,000 students, represents the largest city to adopt it to date.

Pre-paying for school meals by credit card is already common and more and more US schools are now turning to systems that allow parents to track what students eat. But allowing parents to direct what they eat is a new development.

Houston officials hope parents without home computers or access to computers at work will use terminals set aside for them at special “parent rooms” at many of the city’s schools.