Will the government"s new childhood obesity strategy work?

Related: Childhood obesity: UK’s ‘inexcusable’ strategy is wasted opportunity, say experts

There has been a lot of criticism of the government’s new childhood obesity strategy for being “watered down”. What was it originally going to look like?

The government promised a strategy that would take “draconian” action, in the words of health secretary Jeremy Hunt last October, to tackle the very serious obesity epidemic in children. One third of children are overweight or obese by the time they reach 11 years of age. Obesity can lead to major health problems in later life, including heart disease, cancer and diabetes, and costs the NHS more than £4bn every year. NHS boss Simon Stevens has said obesity is going to bankrupt the service.

David Cameron made childhood obesity a flagship issue for his second term, putting officials in No 10 in charge, rather than the department of health. Public Health England (PHE) was asked to investigate the evidence and recommend a series of interventions. Top of the list were hitting supermarket promotions of junk food via multibuys and “bogof” (buy one get one free) offers, and curbs on TV ad for foods high in fat, salt and sugar before 9pm, which would affect family shows such as Britain’s Got Talent and the X-Factor. PHE also backed cutting the sugar and fat content of foods. It supported a tax on sugar-sweetened drinks, but said it would be less effective.

So what did we get?

Instead of this comprehensive strategy, the brief document published this week focused on just two things – reducing sugar consumption and increasing physical activity. There is not a word on advertising or price promotion. And instead of something “draconian”, the focus is on voluntary action, apart from the sugar tax, which had already been announced.

Industry is being asked to reduce the sugar content of foods that children enjoy by 20% by 2020. That is how the Cameron government’s earlier obesity initiative, the Public Health Responsibility Deal, worked. This was a voluntary agreement with food and drink companies to reformulate their foods, reduce portion sizes and so on, but not all companies joined in, and critics say it achieved little.

The British Retail Consortium, representing supermarkets and other outlets, wanted the strategy to make the cuts in sugar mandatory, citing the responsibility deal pledge on cutting salt, which some companies complied with while others did not. But the government has gone firmly down the voluntary road again. The sugar cuts will initially be made in children’s breakfast cereals, yoghurts, biscuits, cakes, confectionery, morning goods (such as pastries), puddings, ice cream and sweet spreads. That does nothing to address the issue of “hidden sugars” in ketchup, pasta sauces, baked beans and all sorts of ready meals, although the document says work will begin later on other foodstuffs.

At the heart of the strategy is the sugar tax, which had already been announced by George Osborne in March. That is only on soft drinks and does not come in for two years. If manufacturers lower the amount of sugar in their drinks, they will escape the tax.

What about fat in the diet?

There is nothing about fat in the strategy – it is all about sugar. But Sara Petersson, of data analysts Euromonitor, says: “It is becoming abundantly clear that replacing a critical ingredient of a product, or single nutrient in a diet, is neither an easy process for food companies nor a successful obesity strategy from a public health point of view.” She adds that “similarly to sugar, fat intake is also higher in diets of countries with higher overweight and obesity rates”. And she points out that replacing sugar with “natural” sweeteners such as honey or coconut sugar will make no difference, because they are just as high in calories.

But surely the measures to get children off the couch and more active will work?

There’s no doubt that children would benefit from more physical activity in all sorts of ways. It is good for mind and body. But it’s no cure for obesity. To burn off a Big Mac cheeseburger, fries and cola, an adult would need to walk for six hours, it has been calculated. All the evidence shows that exercise can help you maintain your weight – but not lose it.

Related: Childhood obesity strategy: not even an E for effort

And there is a question mark over whether children will actually end up running about more. Schools are to be asked to give them 30 minutes’ more physical activity each day. Parents and carers are to be requested to ensure children do a further 30 minutes every day. That will be a big ask for some families.

For a flagship government strategy, did it get the big push you would expect?

Far from it. Instead of a prime-ministerial launch, it was slipped out in mid-August just before the A-level results by the department of health, while Theresa May was on holiday in the Swiss Alps. It would appear that obesity is not the priority it was for David Cameron.

Will the government"s new childhood obesity strategy work?