For a group of academics who spent over a decade pushing food manufacturers to use less salt, success has been so sweet they have decided to take on a new challenge: sugar.
But by opening a new front in their campaign to prevent a health crisis, they say they face a bitter struggle. This time an unappetising blend of government reluctance, vested business interests and fragmented industry regulation lies in their way.
Action on Sugar was launched last month. At a time when many people were defaulting on new year pledges to improve their diets, the organisation said the burden of cutting our sugar intake by up to 40% over the next four years should instead be placed on Britain's food and drink manufacturers. The group will meet Jeremy Hunt, the health secretary, this week to try to persuade him to sign up to their cause.
The health and nutrition experts behind the campaign say that unless Hunt agrees, rising levels of obesity and type 2 diabetes could cost the country up to £50bn a year – more than half of NHS England's current budget.
"It is very difficult to argue with what we're saying," says Graham MacGregor, a professor of cardiovascular medicine and the chairman of Action on Sugar. "Human beings don't need to eat added sugar. It was never a feature of a mammalian diet, because we couldn't get it."
Some academics have controversially likened sugar to addictive drugs such as tobacco or cocaine and accuse the food industry of cynically hooking children and parents on junk food to maximise profits.
Action on Sugar has avoided similar comparisons, instead publishing data that shows how much sugar is ladled into our diets. A tall Starbucks caramel Frappuccino contains 11 teaspoons of sugar – barely two spoons under the recommended daily intake for women. Coca-Cola or Pepsi contains nine per can and a bowl of Kellogg's Frosties has four.
In raising the issue, MacGregor and his team want to replicate the achievements of their earlier campaign, Consensus Action on Salt and Health (Cash). Largely thanks to Cash, our salt intake in foods such as bread, cereals and meat has fallen by 15% in the last seven years, contributing to a reduction in strokes, heart attacks and cases of high blood pressure.
This cutback, done incrementally so that few noticed any difference in taste, was championed by the Food Standards Agency, the government's food safety body. It drew up reduction timetables and even funded research into how bakers could reduce salt levels without ruining their loaves.
Action on Sugar argues that the same gradual reductions could be applied to added sugar with little impact on taste. It says consumers would benefit from improved diets, the government would curb future healthcare costs and manufacturers would save on ingredient costs. "Reformulation is a win-win," says nutritionist Katharine Jenner, the group's campaign director. She says recent pledges by Tesco to cut sugar in its soft drinks and a reduction in the size of Mars and Snickers bars (albeit without a corresponding price drop), shows it can happen.
But, she says, though many food producers may be willing in principle, in reality they are loth to sign up to a voluntary "responsibility deal" on calorie reduction introduced in 2012 by Andrew Lansley, the Conservative former health secretary, because it could damage their market position.
At the root of this problem, says MacGregor, is a 2012 decision to strip responsibility for nutrition from the Food Standards Agency, placing it instead under the political control of the Department of Health under Lansley's successor, Hunt.
MacGregor is scornful of the Conservatives' commitment to reducing sugar and believes changes in the political landscape since the 1990s launch of the anti-salt campaign mean his new project could face strong resistance, much of it driven by a powerful food industry "sugar lobby". "Lansley's responsibility deal is completely bonkers," he says. "Making the food industry responsible for policing itself is a joke."
He dismisses Tesco's promise as having negligible impact. "Tesco's soft drinks account for about 0.5% of the market. What we want is that reduction applied across every single sweet and soft drink that is marketed in the UK, and then we'll see a reduction.
"It's got to be Coca-Cola, Schweppes, every supermarket, everything. And if you do it slowly, and people get used to it and they prefer the drink with less sugar, then you can do it again. This is how the salt thing worked. Do it slowly: incremental reductions, incremental targets."
The Department of Health says it is continuing to discuss the issue with the food industry and is "willing to go further still", but its policy is aimed at fighting obesity by helping people eat fewer calories, of which sugar is only one source. It says 38 firms have signed up to its deal.
Sugar Nutrition UK, a research body funded by sugar manufacturers, disputes Action on Sugar's medical claims. It says sugar consumption is not a cause of diabetes and cannot solely be blamed for obesity. "It is simply not right to say that reducing the amount of sugar in foods will always result in a reduction of calories," it said. "In most cases the sugar will need to be replaced by another ingredient and the reformulated recipes can contain more calories than the original."
Barbara Gallani of the Food and Drink Federation, which represents manufacturers, says more research is needed into how consumers react to new recipes that mean changes to taste, texture and ingredients.
Despite the resistance, MacGregor says Action on Sugar will achieve its goals, even if it has to wait for a change of government. His group has already planned talks with Labour and the Liberal Democrats to persuade them to consider a possible "sugar tax" to enforce blanket reductions.
"If Jeremy Hunt agrees to do this, which is very unlikely, then obviously we'll put them on the back burner. But we do get things done. We will get sugar down the way we've got salt down."
