A woman eats her meal inside a McDonald's fast food restaurant in London, England, on April 30, 2012. British doctors have slammed the sponsorship of the London Olympics by companies like McDonalds, saying it sends the wrong message amid the country's ballooning obesity crisis. (Alastair Grant/AP)

Only a few Tube stops away from the glittering new Olympic Park, a cluster of British swimmers took to a training pool for the start of an intensive session this week. But rather than going for the gold, the swishing mob doing water aerobics to the warbling sounds of disco was engaged in a national fight of a different kind — the battle of the bulge.

As Britain prepares to begin hosting the 2012 Summer Olympics next week, the nation finds itself in the grip of what health advocates describe as an obesity “epidemic,” with the most recent figures showing that 26 percent of English adults are obese, compared with 15 percent in 1993. The rapidly expanding waistlines here underscore what critics call a failure by organizers to live up to one of their top pledges for the London Games: to whip the fattest country in Western Europe into shape.

Britons have one of the most sedentary lifestyles on earth, according to a major study released Wednesday, with more than 63.3 percent of the population defined as inactive — compared with 40.5 percent in the United States and 32.5 percent in France. Though the United States retains the world heavyweight title among major nations — with 35.7 percent of American adults classified as obese — England is catching up, with about a third of its adults projected to be obese by 2015.

Britain is running well short of a stated Olympic goal to get 1 million Brits “off their bums” by the end of 2013, with the government officially dropping that target last December. Opposition lawmakers, meanwhile, are deriding deep cuts made to sports programs in British schools just as the Olympics could have been harnessed to inspire children at risk of becoming overweight.

Yet a number of U.S.-style programs aimed at reducing waistlines in a country that cherishes its pint-in-the-pub culture are nevertheless popping up, such as a new public-pool-based initiative in East London subsidized by the National Health Service. London, meanwhile, is studying some of the radical steps — such as a ban on “supersize” sodas — proposed by New York City to curb calorie intake, with new major measures due out by April to combat what Mayor Boris Johnson has called “a fatness plague” in the capital.

“But let’s face it, it’s going to be a challenge to get Britain athletic again,” said Melissa Gawler, 22, a beaming young woman who described herself as “overweight” and who recently joined the experimental swimming class in London’s Islington neighborhood. “Even with the Olympics coming, we’re still British, and people are always going to like a nice night out with pies and mash and fish and chips.”

Sedentary mind-set

On a recent rainy day in central London, hundreds of British “anti-athletes” gathered in a park for the Chap Olympics — an event of “genteel inactivity” meant to punctuate a point ahead of the Olympic Games. Recent polls have shown that two out of every 10 Britons feel motivated by the Olympics to play more sports, a number that seems logical to the likes of Cathy Wigley, a 37-year-old documentary filmmaker “competing” in the Chap Olympics. She insisted that despite the “Chariots of Fire” image, athletics simply isn’t a strong part of British culture.

In recent years, experts say, Britons have grown more overweight because of sedentary lifestyles and higher consumption of fast food and alcohol. Without doubt, Britain tends to punch above its weight in Olympic medal counts, placing fourth in Beijing in 2008 and besting more-populous nations such as Germany and Japan. Yet for the average Brit, say Wigley and many others here, working out “L.A. style” isn’t part of the mind-set. Wigley, for instance, entered a Chap Olympics event titled “Not Playing Tennis” — in which contestants sat in lawn chairs sipping cocktails while languidly (and only occasionally) hitting at a ball on a string. Like most satire, the event contained what many here call more than a drop of truth.

“No one wants to be caught sweating in Britain,” said Wigley, flashing a wry smile. “Exercise is just too exhausting, isn’t it?”

But to a growing number of health advocates, British inactivity is no laughing matter. The study released Wednesday in the British medical journal the Lancet suggests that global mortality rates from a lack of exercise are now as high as those from smoking. In Britain, health professionals are at least partly blaming increasing levels of obesity for heart disease and other health conditions that are costing the country more than $15 billion a year.

The Olympics were seen by many in Britain as a catalyst for change. Tessa Jowell, who was Olympics minister in a Labor government that lost to a Conservative-led coalition in 2010, was key to establishing the goal of getting 1 million Britons physically active at least three times a week by the end of 2013 — a goal abandoned seven months ago by the new government, which called the target “artificial.” It also seemed unattainable: Overall, new national surveys show that about 500,000 more Britons are exercising three times a week, a figure well short of where organizers hoped they’d be. In addition, the number of young adults exercising has actually declined.

Too little, too late?

During the 2000s, the Labor Party also rolled out a School Sports Partnership that earmarked more than $250 million per year to physical education in schools and set targets to provide British children with two to five hours of physical activity each week. The program allowed schools to bring in specialist instructors, teaching not only popular sports such as soccer but also fencing, golf and cricket.

But the new government abandoned those weekly targets in schools and slashed funding for the School Sports Partnership. Though physical education is still mandatory in British schools, how much and what kind of sports are provided remain largely the purview of the schools.

“It is very easy to make promises, but they are complex to deliver and require a long-term commitment in order for change to be realized,” Jowell said. “I think you’d have to accept that there was a setback by getting rid of the School Sports Partnership.”

Hugh Robertson, Britain’s current Olympics minister, defended the Conservative-led government’s response. It is, for instance, trying to bring competitive sports back to schools after years of liberal policies that saw them as potentially damaging to children who underperformed. At the same time, he defended the government cuts: “To just pretend that you can blithely sail along throwing money at everything in exactly the same way post the global recession as you did before it, is frankly living in Wonderland.”

Critics also decry the response to rising obesity rates as too little, too late. But programs are being launched to fight the British bulge — with several tied to the Olympic Games. They include a push by supermarkets to stock more lower-calorie foods and a national ad campaign pleading with Britons to change their lifestyles.

Yet a study published Wednesday by a House of Lords committee suggested that would be an uphill battle, showing that even British doctors appear largely unaware of government guidelines calling for 21 / 2 hours of exercise per week.

“It’s not like we don’t want to be healthy,” said Gawler, the 22-year-old who joined the new National Health Service swimming program in March. “But it’s hard to change, especially with the economy not doing well. Even in London, it’s just cheaper, and easier, to go to McDonald’s or Burger King.”

Karla Adam and Eliza Mackintosh contributed to this report.