Obesity: a case study

To illustrate the need to address both upstream and downstream issues and to support effective action by individuals, communities, health services and other organisations, the section below considers one health issue currently causing much concern – obesity. The Government has published a new cross-

departmental strategy which seeks to reverse the trend in rising obesity and overweight, particularly among children.

However, any number of health issues could have been chosen to demonstrate a similarly complex picture.

Obesity: a case study

Obesity is one of the most widely discussed public health issues of the moment, with varying views about the solutions. In recent years the proportion of people who are overweight or obese has increased significantly across the UK, and London is no exception. Of particular concern is the increase in childhood obesity. This case study attempts to demonstrate the complexity of this issue and highlights the need for more coordinated responses at a range of levels.

It is important to distinguish between ‘overweight’ and ‘obese’. These are clinical terms that refer to a person’s body mass. Adults with a body mass index (BMI)25

between 25 and 30 kg/m2 are described as overweight, while those with a BMI greater than 30kg/m2 are described as obese. For people with a BMI of over 25kg/m2 the risks of health problems increase as their BMI increases. Being overweight and obese is linked to a wide range of health problems including cardiovascular conditions, type 2 diabetes, cancers and mental illness. In 2003 obesity caused approx- imately 4000 deaths in London, seven per cent of all London deaths, including 600 from heart attacks, 450 from strokes and high blood pressure and over 300 from cancers26

.

The 2003 Health Survey for England shows that, in 2003, 18 per cent of men and 20 per cent of women in London were obese. This amounts to approximately 1.3 million obese adult Londoners27

. The proportion of young people that were obese was just as high, with 20 per cent of people between the ages of 2 and 15 (0.25 million young Londoners) obese in the same year28

. In 1975 only around eight per cent of children were overweight.

Diet and levels of physical activity are the direct determinants of body mass for the vast majority of people. High calorie, high fat diets are closely linked to being overweight and obese. Similarly people who are regularly physically active are much less likely to be overweight or obese than those who are more sedentary. The 2006 Active People survey by Sport England found that approximately 50 per cent of Londoners were ‘sedentary’ – meaning that they had done no 30 minute bouts of moderate intensity physical activity in the preceding three months29

. There are a wide range of social, economic and environmental factors that affect Londoners’ diets and levels of physical activity. These factors do not wholly account for, but have a significant influence on individual choices. Therefore to get people to change their behaviour action is needed to create conditions that make healthy choices easier.

Thinking firstly about social factors, the different diets of various groups of Londoners partly reflect social trends such as longer working hours. Reduced time for food purchasing and preparation has led to the consumption of more ready-made snacks and meals30

. This has a negative impact on food

knowledge and cooking skills and their transfer from one generation to the next. Significantly, national evidence shows that children of obese parents are much more likely to be obese themselves31

. Increasing the flexibility of work should help to address this issue. More specific responses should focus on education to improve nutritional knowledge and food preparation skills for people of all ages.

Cultural traditions and preferences are also important. For example, national data shows that Chinese men and women consume fruit and vegetables more frequently than other ethnic groups, whereas Irish and Bangladeshi men and women consume high fat foods more frequently than other groups32

. Changing the kinds of fats used and developing lower fat versions of some traditional foods is one way of addressing these issues.

Similarly there are social and cultural reasons why some groups have low levels of participation in sport and physical activity. For example, levels of physical activity among disabled Londoners are very low33

. Disabled people face physical and social barriers because sports centres and open spaces are not designed in a way that is accessible to them, and because activities themselves are often structured around the needs and skills of able-bodied people. Participation is also lower among women than men, and particularly low among women who belong to certain faith groups due to requirements around privacy and the need for gender specific spaces. Promoting sport and physical activity among groups that currently have low levels of participation and tailoring services to their needs such as by providing women only

sessions has been shown to improve participation levels among these groups. In terms of economic factors, income is hugely important. People on lower incomes tend to consume relatively low amounts of fresh fruit and

vegetables, and relatively high amounts of refined sugars, saturated fats, and salt. This is partly due to cost. High fat, high sugar foods often cost less than fruit, vegetables and lean meats, particularly when considered in terms of cost per unit of energy34

. However, direct cost is not the only consideration. Parents living on low incomes often comment that they regularly buy highly processed foods (such as burgers, pizzas and chips) for their families because they are confident that these foods will be eaten and they cannot afford to buy foods that their families might reject and waste. Clearly action to improve the availability of affordable healthy food is important here. Education about budgeting and preparing low cost healthy meals can also support people on small budgets to make good food choices.

Low-income groups also have lower levels of physical activity. The 2006 Sport England Active People Survey found that only 15 per cent of people in the lowest socio-economic groups reported regular participation in sport and active recreation, compared to 26 per cent of the highest socio-economic group35

(see map on page 66). In London the costs of participating in many forms of sport and physical activity (both in terms of facilities and

equipment) are not affordable for people living on low incomes. Increasing low cost access to sporting facilities, and raising awareness about low cost options would be one way to address this. Promoting and supporting low cost physical activities such as walking and cycling also has potential to make a difference, especially as there is evidence that people living in low-income areas are more likely to travel as pedestrians36

.

While cost does not limit participation in walking, environmental factors such as urban design, and perceptions of safety do. Environmental equity is an important issue in London. Londoners living in deprived areas often breathe poorer quality air, have less access to high quality green space, and face higher perceived and actual levels of crime. Pedestrian injury rates are also higher among more deprived Londoners, with the rate amongst the most deprived tenth nearly three times that among the least deprived, for both adults and children37

. All of these factors can have a negative impact on levels of physical activity among deprived groups. The introduction of traffic calming measures and safe play zones can help to make local neigh- bourhoods safer for pedestrians and cyclists, as can the work of safer

neighbourhood teams. At the strategic level environmental equity issues need to be considered when planning new developments and in regeneration initiatives.

Local environments affect diet too. Deprived areas often have fewer local food suppliers that stock fresh healthy foods. These areas are described as ‘food deserts’. For example in Newham more than two thirds of residents live more than 500 metres from a shop selling fresh fruit and vegetables38

. Work to improve the availability of healthy food options in deprived areas is therefore important. Other potential ways of improving the environments for healthy eating include increasing the provision of allotments so that local people are able to grow their own food. This would also help to increase physical activity.

In summary, this case study shows that reducing levels of obesity in London is a complex task. Action to address structural factors such as poverty or a degraded physical environment in a deprived area must be co-ordinated with programmes that support and persuade individual Londoners to eat a