So says Joe Harvey of the Health Education Trust who has just completed a trial of healthy drinks vending in secondary schools for the Food Standards Agency, the independent watchdog. Heads who fail to act "clearly give nothing but a fig for their children's health and should be savagely criticised", he says.
Strong words, but Mr Harvey is not without allies. Last year, the World Health Organisation, in a report on nutrition and obesity that outraged the soft-drinks industry, called for school vending machines to be banned.
Parents in this country would happily drive the machines to the tip, according to a survey late last year by pollsters YouGov. It found that 81 per cent of parents said they would like schools to ditch junk food and drinks vending.
They have a point. In the UK, 13 to 17-year-olds drink 250 litres of carbonated drinks each year, according to Datamonitor, a business information company. A fifth of seven to 10-year-olds drink nearly 10 cans of pop a week, each of which contains about 10 teaspoons of sugar.
In the 1970s, adolescents in the United States drank twice as much milk as pop. Now the situation is reversed. But schools are beginning to react against the sugary tide, driving Coca-Cola to release new guidelines for schools in the hope of improving its image. In New York and Los Angeles County, high-sugar drinks are on the way out.
In voting to end the sale of pop in vending machines and cafeterias by this month, the Los Angeles school board rejected arguments that its schools needed the money they make from the drinks, saying that students' health came first.
But scrapping profitable vending machines is not the only answer. The FSA trial of healthy alternatives pitted machines selling chilled milk, pure fruit juices and bottled water against their high-sugar rivals. "These machines were put in without asking for other vending to be moved. They sit next to Coke and Nestle machines. They're in the real world. No favours asked," says Mr Harvey.
And they succeeded. The FSA report due out soon will prove to heads that healthy drinks vending is very viable. "Chilled milk, water and juice just flew off the shelf."
"Vending is dominated by multinational giants who have no interest in the health and welfare of children, but are only interested in paying their shareholders," says Mr Harvey.
It has always been in the power of heads and governors to improve vending, he says. Even if they are locked into a deal with an outside caterer, they can threaten not to renew the contract. "The big caterers, Scholarest, Sodhexo and Initial, are not stupid. They know they have to move in the way schools want."
One head who has proved this is David Jarrett of the independent boys Reed's school in Cobham, Surrey. In September 2002, alarmed by the lack of fitness of his pupils and their boisterous behaviour in the afternoons, he decided to institute a healthy food policy. Helped by Sodexho and a new young French chef, the school has transformed its children's diet. Drinks vending became healthy. And far from seeing "lots of lovely lolly vanishing from the budget", Alan Bott, the bursar, is pleased to report a 20 per cent increase in profits.