The Atkins diet empire is to to fund a health and fitness campaign in US schools under a deal with America’s largest teaching union.

But the venture has been denounced by experts as a marketing vehicle for the controversial low-carbohydrate diet.

Nationally Atkins Nutritionals will sponsor a school health website, research on the “childhood obesity crisis” and measures to combat it for state education leaders, plus a nutrition and activity programme across New York schools.

The firm’s role was agreed by the National Education Association, New York State United Teachers and the National Association of State School Boards.

An NEA spokesperson said the money came with no strings and the union retained ultimate control over the content of the website and additional printed material.

Dr. Stuart Trager, Atkins medical director, said the firm was just doing its bit as a “good corporate citizen” to tackle the child obesity epidemic and would not directly promote its diet or food products and supplements to children.

But Dr David Katz, director of medical studies in public health at Yale university, alleged the deal was a “disreputable” ploy for Atkins to “build the next generation of Atkins-ites,” and “link its products to schools, so people will say: ‘Gee, if it’s been let in the schools, it can’t be bad’.”

He added: “I’m appalled that the teachers’ union didn’t recognise (this) and step away.”

Nine million - or 16.5 per cent - of US youngsters aged six to 19 are overweight. A recent report found poor nutrition and sedentary lifestyles are costing schools millions of dollars from absenteeism, as funding is pegged to attendance, and that obesity-related absence is hindering academic performance and tying up staff in remedial work.

An estimated one in three Americans has tried Atkins, including actors Renee Zellweger and Jennifer Aniston. Devotees credit it with helping them shed weight quickly. But concerns have been raised about the long-term impact on health of a diet that tells adherents to gorge on meat and cheese and cut down on fruit, vegetables and whole grains, initially at least.

“The diet tells us to walk away from whole grains,” said Dr Katz. Yet these reduce the risk of cancer and heart disease, while fruit and vegetables delay aging and promote longevity, he said. Followed long-term, the diet could cause intestinal damage, osteoporosis and kidney stones, he added.