New government initiatives to tackle obesity— but will they work?

In 2004, the UK government published a public health White Paper making obesity a key priority. It pledged to halt the year on year rise of obesity in children under 11 years of age by 2010.1 It is already clear that this target will not be met. Indeed, current forecasts suggest that, by 2010, 33% of men, 28% of women and about a fifth of children will have passed the clinical threshold of obesity.2 The current projection of some one million obese children by 2010 is a disgrace, according to Tam Fry, spokesman for the National Obesity Forum. As he has pointed out, the major flaw in dealing with obesity so far is that the government has concentrated more on cure than prevention. If current levels continue, the consequences for the future health and wellbeing of the present generation of children will undoubtedly be disastrous. It is predicted that this will be the first generation for over a century where children die before their parents.3 The most common and serious consequences of childhood obesity are cardiovascular disease and the premature onset of type 2 diabetes. In 1986, a Canadian research group began to record cases of type 2 diabetes occurring under the age of 17 years.4 By 2002, they had collected 86 cases. There had been two deaths aged 28 and 31 years and three girls were on dialysis for end-stage renal failure, one of whom was blind. Of 56 pregnancies only 35 had resulted in live births. Type 2 diabetes, a disorder of middle age just a generation ago, now ranks among the fastest growing disorders of paediatric practice across the industrialised world.5 These data starkly indicate what the future holds for generations of children unless we halt and reverse the relentless rise in the prevalence of childhood obesity. In October 2007, ‘ Tackling Obesities: Future Choices', the largest ever UK study into obesity, was published.6 Compiled by the government’ s Foresight think-tank, this is an in-depth two-year study by almost 250 experts and scientists to examine the causes of obesity and map future trends. The aim is to help government plan effective policies both now and in the future. The report recognises that excess weight is now the norm in our ‘ obesogenic’ society. Importantly, it also acknowledges that individuals can no longer be held responsible for obesity and that the government must act to stop Britain ‘ sleepwalking’ into a crisis— welcome recognition at last that healthy lifestyle choices are not always available, affordable or even understood. The report goes on to say that dramatic and comprehensive action is required to stop the majority of us becoming obese. If current levels continue, it claims, around 60% of men, 50% of women and 25% of children in the UK will be obese by 2050. The Foresight report makes clear that proof of any anti-obesity policies actually working is ‘ scant’, and that evidence for effective preventative measures is ‘ weak’. Nevertheless, yet another policy document, this one entitled ‘ Healthy Weight, Healthy Lives’, appeared in January 2008.7 In the foreword, the Prime Minister sets out an ‘ ambitious goal’ of not only reversing the trend in rising obesity, but reducing it ‘ back to the 2000 levels by 2020’. As the British Heart Foundation points out, this is a ‘softer, more distant’ target than one originally proposed— to halt childhood obesity rates by 2010— and it accuses the government of backtracking on its promises. A £75 million marketing campaign to persuade parents to improve their children's diet and encourage physical activity. A code of practice to be agreed with the food and drink industry. £30 million invested in ‘ healthy towns’ to encourage walking, cycling and other activities. Increased funding over three years for personalised weight-loss programmes and competitions in workplaces and the community. Cookery lessons compulsory in all secondary schools by 2011. Ofcom, the independent regulator for the UK advertising industry, to bring forward a review into junk-food advertising to children. While any new initiatives are to be welcomed, there remains a frustrating lack of evidence to justify the seemingly endless raft of government initiatives to tackle obesity. The story, to date, has been one of unfulfilled pledges and unrealistic targets. As Shadow Health Secretary Andrew Lansley commented recently, the present government has been ‘serially incompetent’ in dealing with the obesity crisis. This may be unduly harsh, however, as government finds itself between a rock and a hard place. The political pressure to act is immense, while the evidence base on which to do so is meagre. The Department of Health may want evidence-based solutions, but there is virtually no evidence base at present in childhood, where the problem almost certainly begins. How, for example do the various factors that determine obesity interact, what is their relative importance and how do they change as a child grows and matures? Crucially, at what age do children gain the excess weight that puts them at risk? If we already know the answers to these questions, all well and good, but in reality we do not. The benefits of providing a piece of fruit at school or two hours of physical education (PE) a week, while intuitively good, are in reality unknown and will remain so until the underlying mechanisms for childhood obesity are clearly understood. Only then will it become clear when, where and towards whom scarce resources should be targeted. This has to be a key issue. There should be a needs-driven, not a supply-driven strategy to tackle obesity. Some of the supply initiatives that have been suggested, even if accomplished, may offer little benefit to health because their relationships to health remain unknown. If we are to succeed in halting the year on year rise in childhood obesity and limit the damage to the health of future generations, we need to know more about how the risks associated with obesity develop. To this end it is necessary to establish trends and associations, in order to attempt predictions. This means a cohort of contemporary children, and repeated measurement throughout their childhood of anthropometry, body composition, energy expenditure, physical activity, dietary choice, blood pressure, insulin resistance and its metabolic correlates. Only then will it be possible to characterise, from an early age, those who are at high risk in order to take preventative action. Such a study is underway. The EarlyBird Study based at the Peninsula Medical School at Plymouth is an innovative non-intervention cohort study that seeks to characterise which children are at risk.8 The study, now in its ninth year, is distinctive in combining criterion measures of body composition with physical activity, energy expenditure, arterial health and fasting blood samples, and has made some novel, if sometimes challenging, observations. Physical activity is an example. Crucially, the activity undertaken by young children bears little relationship to opportunity or facilities offered, which might help explain the lack of success to date of certain initiatives. In one report, less than 1% of the four-fold variation in physical activity among young children could be explained by the five-fold variation in PE opportunity at school.9 Being driven to school may not be eco-friendly, but it does not appear to reduce a child's overall activity— the children make up for it elsewhere in the day.10 It seems that children may be genetically ‘programmed’ to be physically active or inactive. EarlyBird's ‘activitystat’ hypothesis proposes that a child's activity is regulated in the brain, rather than the environment.11 There is certainly little evidence that better facilities or opportunities for recreation will increase physical activity in free-living children. Less active children tend to be overweight, and our prejudice assumes that inactivity is the cause of the overweight. Only a longitudinal study can test which comes first— which is cause, and which is effect. Some recent analyses of the EarlyBird data suggest that overweight may be the cause of inactivity— a fundamentally important finding when so much effort and money are being put into increasing provision for sporting facilities. Indeed, there is no real evidence that children exercise less overall now than they did a generation ago, because there were previously no objective means of measuring physical activity. Children may simply have exchanged one ‘ sedentary’ pursuit for another. All children gain weight as they grow, but the EarlyBird data suggest that 90% of the excess weight gained by girls up to the age of nine (almost 70% in boys) is gained before the age of five years. Strategies that target school-age activities— school meals, school PE, ‘ screen time’, after-school clubs and so on— may be too little and too late, especially if excess calorie consumption in the early years, rather than underactivity, proves to be the key determinant of the current obesity crisis. Halting obesity among pre-school children should be seen as a priority. While countless millions continue to be spent on obesity management, there is little financial support to create the evidence base that is key to obesity prevention. Politicians must acknowledge the importance of investing now, rather than later, in the future health of our children. I am grateful to Professor Colin Waine OBE, Chair of the National Obesity Forum, for kindly reading through the draft manuscript.

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