The body that represents every doctor in the country has launched an unprecedented attack on the coalition government's failed strategy to tackle an obesity epidemic in the UK.

The Academy of Medical Royal Colleges demands "bold and tough" measures to put an end to the role of "irresponsible marketing" by major food and drinks firms in fuelling the crisis. It calls on the health secretary, Andrew Lansley, to ditch the government's "inherently flawed" approach, which trusts the industry to voluntarily cut calories, reduce portion sizes and advise the public on healthy eating.

Instead, the academy's vice-president, Professor Terence Stephenson, says the government must take on the major brands, some of which he likens to the tobacco giants of the last century that stalled radical measures designed to save lives in order to protect their profits.

According to the latest research, 48% of men and 43% of women in the UK will be obese by 2030, a trend that will significantly increase the prevalence of strokes, heart disease and cancer, and lead to higher costs for the NHS. The academy, an umbrella organisation for the medical royal colleges and their 200,000 members, demands:

■ A ban on firms such as McDonald's and Coca-Cola from sponsoring major sports events such as the Olympics.

■ A safe area around schools where fast-food outlets are not allowed.

■ A prohibition on the use of celebrities or cartoon figures to sell unhealthy food and drink to children.

■ A legal obligation on all food and drink manufacturers to publish on their products clear guidelines about the amount of calories, sugar, fat and salt.

■ Consideration of "fat taxes" similar to those being implemented in Scandinavia, designed to penalise the buyers of food and drink high in salt, sugar and fat.

Stephenson said the academy was speaking out as it launched an investigation into what can be done to curb the rise in obesity. It will spend six months researching the causes and effects of obesity, and in the autumn will produce a report that will contain far-reaching recommendations for action.

Charlie Powell, campaigns director of the Children's Food Campaign, applauded the academy's intervention. He said: "Andrew Lansley should act on this excellent set of robust recommendations, but his track record suggests that he will once again ignore the advice of our best medical experts."

Speaking to the Observer, Stephenson said urgent action, similar to that undertaken to reduce smoking over the past two decades, was necessary to deal with a society that he defined as "obesegenic" – an environment that positively encourages the gaining of weight.

Stephenson, who is also president of the Royal College of Paediatrics and Child Health, which represents the UK's 11,000 children's doctors, said: "What can you do about this obesegenic environment we live in? The fact that Coca-Cola and McDonald's are two of the big corporate sponsors of the Olympic Games is most unhelpful. One of the biggest events we're ever going to see in the UK, all those people watching TV and going through the doors will be seeing this. People must be influenced by it, or why would Coca-Cola spend a lot of money to be at the Olympics?"

A major part of the government's strategy to deal with obesity and drink-related problems has until now been "responsibility deals" in which the major food and drink brands have been asked to voluntarily curb their excesses and use their influence to encourage healthier living.

The health secretary has been a strong supporter of the policy, but Stephenson said it was a mistake. "I think a lot of people would draw analogies with smoking, where the smoking industry for many years seemed to actually fight what was to doctors clearly a growing, important public health issue for individuals. And that's where their profits come from and they sometimes, by appearing to go along with these ideas, they actually stall or prevent more aggressive measures.

"Doctors think it's inherently unlikely that huge companies that make money from selling high-calorie foods and drinks, like McDonald's and Coca-Cola, are going to persuade their customers [to eat more healthily]. It's like asking the petrol companies to say to people, 'why not go on your bicycle?'. It just does not seem likely that's going to happen."

Stephenson also voiced concern that Carling, the beer company, is the title sponsor of the English Football League's Carling Cup. He said: "For adults, beer is a source of calories. I like going to a football match and drinking beer, but it's the high-profile sponsorship that means that every time we mention this trophy, we mention in the same words Carling Cup."

In criticism of other promotional tactics, Stephenson said he was "concerned" that characters from children's films are used to help sell fast food.

Barbara Gallani, director of food safety and science at the Food and Drink Federation, the body that represents the interests of the UK's food and non-alcoholic drinks manufacturers, said the academy was wrong to dismiss the benefits of partnerships between food and drink brands and sports events, although she agreed some action was needed.

She said: "Food manufacturers have a good track record of making positive contributions to improving public health through a wide range of actions, whether it's developing healthy choices, reformulating recipes of some of the nation's favourite foods, or working to improve the food literacy of consumers."

A spokesman for Coca-Cola said: "Without the support of sponsors such as Coca-Cola as many as 170 of the 200 national Olympic committees would be unable to send athletes to compete."

A Department of Health spokesman said the government was committed to identifying the best possible evidence of what works in tackling obesity.