A recent report showed that half the UK is heading to be obese by 2050. How did we get so fat and what is being done about it? Peta Bee says it times to get off our butts

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What we thought was an obesity nightmare is turning into what experts say is worse than the “doomsday scenario” it was set out to be. Last week, a report by the National Obesity Forum (NOF) suggested that the prediction that half the UK population will be obese by 2050 "underestimates" the problem. The lobbying group said Britain was in danger of surpassing the prediction contained in a 2007 paper called the Foresight Report.

So serious is the problem, that the NOF is calling for programmes that attempt to tackle fatness in the way that smoking has been targeted in recent years. "We've seen hard-hitting campaigns against smoking and it's time to back up the work that's already being done with a similar approach for obesity," says Professor David Haslam, chair of the NOF.

How on earth did we get so fat? Of course, it’s much to do with the ingredients that lurk in the food we eat. For years we were told that high fat foods were the enemy of the waistline. Now advice has swung full circle and obesity campaigners are now piling the pressure on manufacturers and the government to cut sugar levels in food by up to 30 per cent. It is a move that is long overdue and that sort of reduction could cut our calorie intake by about 100 kcal a day, resulting in considerably fewer poundage gained in a year. “Historically, fat was believed to be the villain,” says Tam Fry, spokesperson for the NOF. “Now sugar is known to play a substantial role in weight gain.”

Sugar is hidden in the most unlikely places. Apparently healthy breakfast cereals, smoothies and even soups and sauces are loaded with the stuff. There are nine teaspoons of sugar in a standard 330ml can of Coke and six teaspoons in a 375g portion of Sharwood's sweet and sour chicken with rice. A serving of Kellogg's Frosties contains four teaspoons and Heinz classic tomato soup has four teaspoons in 300g. “There has to be some sugar, fat and salt in certain foods, but currently the levels of them are astronomic in too many products,” says Fry.

“Colossal portion sizes served in restaurants and cafes are not helping.” Neither, he says, is the culture of grazing, of coffee shop stops where calories are unwittingly consumed by the 100 in drinks and snacks and by the trend for takeaway meals and lunches.

But while the proposed gradual sugar cuts will help, they will be mostly in ready meals, sweets and soft drinks - precisely the foods we would be better off not buying at all. It hardly takes a rocket scientist to work out that were we to minimise our intake of foods to which sugar can be added during manufacturing processes, then we instantly cut our consumption. “Like fat, sugar is only going to cause problems when it is eaten to excess,” Fry says. “If we eat more plants, more naturally-derived foods and less ready made produce, then levels will be cut dramatically.” The very broad bottom line is that we eat the wrong things and we eat way too much of them. While the food industry is wrong for plying foods with unhealthy ingredients, we are also at fault for eating them.

MORE GLOSS: Why low-fat isn't better for you

It doesn’t help that our unimpressive diet habits are coupled with a woeful decline in activity levels. As Fry points out, “It is not so much sugar or fat, but the fact that we are not burning off the calories that they provide that is resulting in obesity”. We are more deskbound than ever before, do less housework, less shopping, less of everything that involves muscular and cardiovascular effort. A survey of more than 8,000 people by Saga attributed the expansion of women’s waistlines by six inches over the past 60 years to them not doing as much cleaning, sweeping, gardening and other household chores as their forebears.

Two years ago scientists outlined in the Lancet medical journal labelled us one of the most sedentary populations in the world. We are more slothful even than the Americans, a nation with a reputation for having an aversion to walking. Anywhere. The report showed we were twice as inactive as the French. We sit down for eight hours or more a day. And we drive rather than walk; figures from the RAC show that total mileage driven is up nearly 20 per cent in the last two decades.

We join gyms in droves, but then fail to use them. Fitness First’s new US owners have just announced they are investing almost £270m in a strategy based on “behavioural psychology” to ensure members get more support and encouragement to stick to their fitness goals after the initial January burst. Even those who do complete a daily workout are not immune to the side effects of sedentary lifestyles. Last year, researchers at the School of Public Health at the University of Texas got in touch with more than 200 male and female runners taking part in the local half or full marathon race to ask them about their training. As expected, they found that the runners were putting in up to seven hours of training a week to prepare for their challenge. What was shocking, however, was that they were inactive for much of the rest of their time. On an average workday, the runners reported sitting for more than 10 hours a day at work and at home, higher than the US and UK national average. Even at the weekend, the runners spent about eight hours sitting down.

And the consequences of such chronic sitting habits are frightening. An Australian study in the British Journal of Sports Medicine recently revealed that an hour of TV a day can steal 22 minutes of your life. A man who watches no TV during his adulthood might live 1.8 years longer and a non-TV watching woman 1.5 years longer than someone who sits in front of the box every night.

Are things set to improve? It looks unlikely. Findings from a new survey commissioned by Nike, ‘Designed to Move’, suggest that UK activity levels have already plummeted by one fifth in fewer than two generations and it is anticipated we will be 35 per cent less active than our grandparents were by 2030. Inactive children are twice as likely to become obese adults and their generation is predicted to suffer 5.3 million premature deaths worldwide as a result of them not moving. It makes today’s schoolchildren the first generation in centuries who are increasingly unlikely to outlive their own parents.

With both diet and exercise we are too easily lulled into a false sense of security. We can apportion blame to the food industry and to our time crunched lives for allowing little time to exercise, but ultimately the key to cutting the risk of obesity lies in our own hands.  “Part of the problem is that being called fat is viewed as an insult and that no one likes to be told that they are overweight, even by a healthcare professional who has the best interests of the patient's health at heart," says the latest NOF document.

We need to deal with fatness head on. “Tackle it by reading labels, avoiding foods with high levels of sugar and fat, but crucially by moving as much as possible,” says Fry. “The overriding message we want to send to the nation is: get off your butt!”