Britain's 220,000 doctors are demanding a 20% increase in the cost of sugary drinks, fewer fast food outlets near schools and a ban on unhealthy food in hospitals to prevent the country's spiralling obesity crisis becoming unresolvable.

The Academy of Medical Royal Colleges is calling for action by ministers, the NHS, councils and food firms, as well as changes in parental behaviour, to break the cycle of "generation after generation falling victim to obesity-related illnesses and death".

In a report spelling out the problem in stark terms, the academy says doctors are "united in seeing the epidemic of obesity as the greatest public health crisis facing the UK. The consequences of obesity include diabetes, heart disease and cancer and people are dying needlessly from avoidable diseases."

The academy castigates attempts by previous and current governments to counter obesity as "piecemeal and disappointingly ineffective", and woefully inadequate given the scale of the problem. One in four adults in England is obese, and the figures are predicted to rise to 60% of men, 50% of women and 25% of children by 2050.

Following a year-long inquiry the academy has drawn up a 10-point action plan – including health professionals routinely asking overweight patients about their lifestyle, and help for new parents with their babies' feeding habits – to end the UK's status as "the fat man of Europe".

The academy's chairman, Professor Terence Stephenson, said the report did not claim to offer a full solution to obesity, but "it does say we need together to do more, starting right now, before the problem becomes worse and the NHS can no longer cope". Obesity is estimated to cost the NHS £5.1bn a year.

The report puts forward measures it says "society as a whole needs to take to prevent the obesity crisis becoming unresolvable". Calling for a reversal of widespread unhealthy habits, it adds: "Just as the challenges of persuading society that the deeply embedded habit of smoking was against its better interests, changing how we eat and exercise is now a matter of necessity."

The academy wants a dramatic increase in anti-obesity efforts. Its 10 recommendations to end what it calls the "obesogenic environment" include backing for:

• An experimental 20% tax on sugary soft drinks for at least a year, like that in operation in parts of the US, to see what effect it has on sales. The potential £1bn annual tax yield could help fund an increase in weight management programmes.

• Local councils to limit the number of fast food outlets allowed to operate near schools, colleges, leisure centres and other places where children gather, to end the "paradox" of schools that try to get pupils to eat healthy lunches having their efforts undermined by council-licensed burger vans outside their gates.

• NHS staff to routinely talk to overweight patients about their eating and exercise habits at every appointment and offer them help, under a policy of "making every contact count".

• The NHS to spend at least £300m over the next three years to tackle the serious shortage in weight management programmes so many more patients with weight problems can be referred and helped "in a supportive and sensitive manner".

• An expansion of bariatric surgery for more severe obesity, from the current total of about 8,000 NHS operations a year, to help those most at risk of dying.

• Hospitals to adopt the same nutritional standards for the food they serve patients and staff that already apply in state schools in England, and an end to fast food outlets and vending machines selling unhealthy products on hospital premises.

• Health visitors to advise new parents how to feed their children properly, to avoid them getting hooked on sweet or fatty foods while still very young.

• All schools to have to serve healthy food in their canteens, including academies and free schools, which the education secretary, Michael Gove, has exempted from the requirement that applies in all other state schools.

• A ban on television advertisements for foods high in salt, sugar and

saturated fat before the 9pm watershed, as current restrictions to

minimise children's exposure to them have not worked.

The report says it is "perplexing" to find canteens in hospitals, which should be setting an example, selling unhealthy dishes, and "even more astonishing that in many hospital receptions patients pass by high street fast food franchises or vending machines selling confectionery, drinks and crisps".

It is scathing of Gove: "It seems to represent the most extraordinary own goal on the part of the current government to exclude the wave of academies from the [nutritional] standards."

Stephenson told the Guardian the 20% tax increase on sugary soft drinks was justified because they represented "useless calories" and were "the ultimate bad food. You're just consuming neat sugar. Your body didn't evolve to handle this kind of thing."

The chef and anti-obesity campaigner Jamie Oliver welcomed the report as "the clearest warning sign yet that the medical profession is deeply concerned about obesity. We need action now to educate children and families on how to choose the right food to give them the best life chances."

The Food and Drink Federation, which represents produce manufacturers, branded the report a "damp squib" that added "little to an important debate". It said the report failed to recognise the role of alcohol in adding calories to adult diets, and said little about physical activity and "health in the workplace".

The federation's spokesperson Terry Jones said: "The Academy of Medical Royal Colleges has presented as its recommendations a collection of unbalanced ideas apparently heavily influenced by single-issue pressure groups."

The Department of Health said it was studying the findings. "The threat posed by obesity in both adults and children represents one of today's most important public health challenges," said a spokesman. "This wide-ranging report recognises, as did our own recent call to action on obesity, that there is no single answer to the obesity problem.

"It is up to everyone – government, industry, health professionals and voluntary groups, as well as individuals themselves – to work jointly to promote healthy eating and healthy lifestyles." .

The British Retail Consortium said it was wrong to "demonise" its members, which include Burger King, McDonalds and KFC. Its spokesperson Richard Dodd said such chains offered a range of items to customers and had reformulated products to reduce fat, sugar and salt content.

"It's wrong to demonise any particular type of food or food outlet. What our members are hugely engaged in is encouraging healthy balanced diets and giving customers the choices and information they need," he said. I

t was also down to parents to help children"build a healthy and responsible attitude to eating a balanced diet overall".

Gavin Partington, director general of the British Soft Drinks Association, said: "We share the recognition that obesity is a major public health priority but reject the idea that a tax on soft drinks, which contribute just 2% of the total calories in the average diet, is going to address a problem which is about overall diet and levels of activity."

"Over the last 10 years, the consumption of soft drinks containing added sugar has fallen by 9%, while the incidence of obesity has been increasing. And 61% of soft drinks now contain no added sugar. Soft drinks companies are also committing to further, voluntary action as part of the government's calorie reduction pledge."