Scottish Health Survey - topic report: UK comparisons

3 DIET, PHYSICAL ACTIVITY AND OBESITY

3.1 INTRODUCTION

This chapter presents findings for three important, and related, risk factors for poor health. Comparable figures exist for Scotland and England for physical activity and fruit and vegetable consumption. ¹ In addition, Northern Ireland also has comparable height and weight data from which the body mass index ( BMI) can be calculated. The Welsh Health Survey includes measures of all these aspects, however its data collection methods are very different (for example, height and weight is self-reported rather than measured directly). Because of these differences, Welsh figures are not reported in this chapter.

Physical inactivity, poor diet and obesity are all significant individual risk factors for numerous chronic diseases and mortality. For example, physical inactivity is associated with ischaemic heart disease, ² diabetes, ³ osteoporosis, ⁴ and certain types of cancer. ⁵, ⁶ Obesity is associated with other serious chronic diseases such as hyperlipidaemia (high levels of fats in the blood that can lead to narrowing and blockages of blood vessels), which is a major risk factor for cardiovascular disease ⁷ and also with cancer, disability, reduced quality of life, and can lead to premature death. ⁸, ⁹, ¹⁰, ¹¹ Obesity has also been shown to be associated with, but not necessarily a direct cause of, respiratory conditions, sleep disturbance, infertility and mental ill-health. ¹², ¹³ Of the many factors associated with the development of obesity, physical inactivity and poor diet are seen as the biggest causes and the two factors for which the evidence is most robust, hence this chapter addresses all three of these together. ¹⁴, ¹⁵

The estimated costs to society of the burdens associated with each risk factor run to billions (based on both the direct costs of treatment and lost productivity). For example, it was estimated that the cost of treating food-related ill health in England in 2007 was £7.7 billion; ¹⁶ the cost to the NHS in Scotland of obesity and obesity-related illnesses was estimated to be in excess of £175 million in 2007/8. ¹⁷

As noted in the Introduction, the recommendations to eat 5 or more portions of fruit and vegetables a day, ¹⁸ and to be moderately physically active for at least 30 minutes on most days a week, apply UK wide. Similarly, the thresholds for classifying people's body mass index ( BMI) as underweight, normal, overweight or obese are internationally defined (by the WHO) and are therefore used throughout the UK. The responsibility for these aspects of public health and sport policy are all devolved, so each country has developed its own specific approaches to improving diet, increasing activity and reducing obesity levels. Unlike the actions to tackle smoking and drinking discussed in the previous chapter, most of the actions to address poor diet, inactivity and obesity have been based on a public health promotion approach rather than legislation. While diet, activity and obesity have at times each been treated as distinct areas requiring policy responses, most of the countries now tend to integrate their policies in these three areas. For this reason, the following discussion highlights key policies and actions relating to diet, physical activity, obesity, or any combination of them, for each country in turn.

3.1.1 Scotland

Scotland's unhealthy eating habits have been the subject of concern for many years. The Scottish Office's 1993 working party on diet ¹⁹ led to the publication of the Scottish Diet Action Plan ²⁰ in 1996. This outlined a series of targets for dietary improvement (the Scottish Dietary Targets). Originally intended to be achieved by 2005, the targets were reviewed in 2003 and a further commitment was made to seeing tangible outcomes by 2010. ²¹ A number of white papers and strategy documents throughout the years have outlined their support for the Scottish Diet Action Plan. ²², ²³ More recently, the Scottish Government's overall diet, physical activity and obesity strategy was set out in the 2008 publication Healthy Eating, Active Living: An action plan to improve diet, increase physical activity and tackle obesity (2008-2011). ²⁴ The document contains a commitment to the underlying principles of the original Diet Action Plan, but suggests that a more pragmatic set of longer term dietary goals to replace the existing ones that expire in 2010 should be considered. This was further reflected in the publication of the Government's National Food and Drink policy in 2009 (Recipe for Success).

Scotland's Physical Activity Task Force ( PATF) was launched in 2001. The 2003 PATF publication Let's Make Scotland More Active: A strategy for physical activity²⁵ set out the following target, which still stands today:

50% of adults should be meeting the current recommended levels of physical activity by the year 2022

A number of the Scottish Government's National Performance Framework national indicators ²⁶ aim to increase physical activity, for example:

Increase the proportion of journeys to work made by public or active transport

Increase the proportion of adults making one or more visits to the outdoors per week

The Better Health, Better Care Action Plan (2007), ²⁷ the Scottish Government's strategy for a healthier Scotland, also outlines how funding will be allocated to help address obesity through dietary and physical activity programmes. Although they were not in place at the time these data were collected, two key documents were published in 2010 - the new SIGN guidelines for management of obesity, ²⁸ and the Scottish Government obesity route map. ²⁹ This route map set out a commitment to developing a population-wide indicator of healthy weight, and a programme of investment across multiple sectors to reduce high calorie food and drink consumption and sedentary behaviour; increase physical activity in everyday life, including walking and cycling; to instill healthy habits in the early years; and encourage employers to promote their employees' health.

3.1.2 England

The public health white paper in England Choosing Health: Making healthy choices easier³⁰ set out the then government's commitments for action on obesity, increasing physical activity and improving diet. Two related action plans, Choosing a Better Diet³¹ and Choosing Activity³² specified the steps that needed to be taken at national, regional and local level to combat obesity and improve people's health through better diet and nutrition and increasing physical activity. The 2008 cross-governmental obesity strategy for England highlighted the need for individuals to know more about healthy eating, lifestyle factors, and the causes and consequences of the rise in unhealthy weight. ³³

In 2006, the National Institute for Health and Clinical Excellence ( NICE) published guidance about physical activity ³⁴ and about obesity. ³⁵ The first of these highlights the contribution of regular physical activity to promoting the health of communities. The second provides guidance for healthcare organisations (both within and external to the NHS in England) on the prevention, identification, assessment and management of overweight and obesity.

While the recommended level of physical activity for adults is the same in Scotland and England, the 2002 sport strategy Game Plan³⁶ set out more ambitious interim and long-term physical activity targets for England. These were for 50% of adults to meet the recommendations by 2011 and 70% to do so by 2020. These targets were replaced in 2009 by three new ones with a slightly different focus, ³⁷ though the new coalition government elected in May 2010 has yet to publish any detailed strategies on these areas.

3.1.3 Northern Ireland

The 2002 Investing for Health Strategy set out the commitment of 'working for a healthier people' in Northern Ireland. ³⁸ The Fit Futures Taskforce was subsequently established in 2004 to examine options for preventing overweight and obesity in children and young people. The Taskforce reported in 2005. ³⁹ It identified six priorities for action which included tackling barriers to eating healthy food, a nutritional signposting system and systematic surveillance of obesity levels, nutrition and activity levels.

A Fit Futures Implementation Plan was developed and published for consultation in 2007 ⁴⁰ and a Fit Futures Programme Board was established to oversee its implementation. A cross-sectoral Obesity Prevention Steering Group was established in 2008 ⁴¹ to oversee the progress against the Fit Futures recommendations, and lead the development of an overarching policy to prevent obesity across the life course. To support the work of the Obesity Prevention Steering Group four policy advisory sub-groups were set up to deal with food and nutrition; physical activity; education, prevention and public information; and data and research. ⁴¹

A Public Health Agency was established in 2009 which now has responsibility for public health initiatives in Northern Ireland. It incorporates the role of the former Health Promotion Agency including, Fit Futures. ⁴² A 10-year obesity prevention strategic framework has been developed and is due to be launched in 2010.

3.2 FRUIT AND VEGETABLE CONSUMPTION

3.2.1 Number of portions consumed in Scotland and England

The questionnaires in both countries were identical with one small exception that the question about fruit juice in Scotland referred to "pure fruit juice" rather than just "fruit juice".

Most adults in Scotland and England did not consume enough fruit and vegetables to meet the recommended five portions a day. However, consumption was lower in Scotland than in England for both men and women; all differences between the countries were statistically significant. The mean number of portions consumed per day by men in Scotland was 3.1 compared with 3.5 in England. The corresponding figures for women were 3.4 and 3.8 portions, respectively. The proportion consuming five or more portions was also significantly lower in Scotland than in England. 20% of men in Scotland met the recommendation compared with 25% of men in England. The equivalent figures for women were 24% and 29%, respectively.

Fruit and vegetable consumption was also lower in Scotland than in England in 2003. The 1995 surveys measured weekly rather than daily fruit consumption, this was also found to be lower in Scotland than in England. Table 3.1, Table A1

3.3 PHYSICAL ACTIVITY

3.3.1 Data collection

Self-reported physical activity measures are well known to have limitations. ⁴³ For example, sports and exercise are typically carried out in a planned and organised manner and therefore are relatively easy to recall. However, routine activities such as domestic activity (housework, gardening, etc) and walking or cycling for travel rather than leisure, are more difficult to recall and report. As a result, there are a number of areas where error may be introduced in subjectively measured activities: ⁴⁴

Participants may experience difficulty in recalling all activities. This can lead to either under-reporting, if they omit activities, or over reporting, if they include activities beyond the recall period or over estimate their duration or intensity.

The kinds of physical activity included in this report are not limited to participation in sports and structured exercise, but also cover other forms of activity which people may engage in as part of their daily lives, for example walking, housework or a physical job. Full details of the questions asked in Scotland and England are provided in Appendix 1. The questions themselves are comparable, however it should be noted that, for historic reasons, Scotland and England use different methods to convert reported activities into minutes of participation. To make the estimates comparable the English data has been re-analysed using the Scottish method. Further details of this are given in the Appendix.

3.3.2 Proportions meeting the physical activity recommendations in Scotland and England

People who had participated in 30 minutes or more of at least moderate activity on five or more days a week were classified as meeting the physical activity recommendations. Activities were counted if they lasted at least 10 minutes. The proportion who met the recommendations was the same in both countries: 45% for men and 33% for women. Table 3.2

Before 2008 the physical activity questionnaires in Scotland did not ask about activities under 15 minutes, and in some years the questions in England set a lower limit of 30 minutes. As a result of this, the trend data use a different definition of meeting the recommendations. However, the validity of the difference between the countries would only be affected if the prevalence of participating in short bouts of activity was different. This is unknown, so the following needs to bear this caveat in mind. Previous comparisons of physical activity in Scotland and England have found inconsistent patterns. In 2003 activity levels were higher in Scotland than England, in 1998 they were the same (as they are now), whereas in 1995 activity was lower in Scotland than England.

3.4 overweight and obesity

3.4.1 Measuring body mass index ( BMI)

Interviewers took direct measurements of height and weight in all three surveys using the same measurement protocols (details of these can be found in each of their corresponding technical reports). ⁴⁵, ⁴⁶, ⁴⁷

The Body Mass Index ( BMI), defined as weight (kg)/height (m ²), is a widely accepted measure that allows for differences in weight due to height. It has been measured in each of the Scottish and English surveys to date, and in the recent Northern Irish surveys. BMI has some limitations because it does not distinguish between mass due to body fat and mass due to muscular physique, nor does it not take account of the distribution of fat. ⁴⁸, ⁴⁹ However, as these limitations apply equally to all surveys they do not affect the comparability of the estimates presented here.

Based on their BMI, adults were classified as being in one of the following groups:

BMI (kg/m 2)	Description
Less than 18.5	Underweight
18.5 to less than 25	Normal
25 to less than 30	Overweight
30 to less than 40	Obese, excluding morbidly obese
40+	Morbidly obese

The findings below compare mean BMI, the proportion classified as overweight or obese ( BMI of 25 kg/m ² or more), and the proportion who were obese ( BMI of 30 kg/m ² or more).

3.4.2 BMI in Scotland, England and Northern Ireland

Mean BMI in Scotland was not significantly different to that in England or Northern Ireland for either sex. However, the patterns in the prevalence of overweight including obesity, and obesity were a little more complex. Among men, the prevalence of overweight including obesity ( BMI >25) was significantly higher in Scotland (68.5%) than in Northern Ireland (64.1%). The difference between men in Scotland and England (65.9%) was not significant. The prevalence of obesity ( BMI >30) in men in Scotland (26.0%) did not differ significantly to that in England (24.1%) or Northern Ireland (24.4%).

The picture was slightly clearer for women. Overweight including obesity prevalence was 61.8% in Scotland, this was significantly higher than in England (56.9%) and Northern Ireland (54.0%). The prevalence of obesity in women followed a similar pattern, though the difference between Scotland and England was only marginally significant in this instance. 27.5% of women in Scotland were obese compared with 24.9% in England and 23.5% in Northern Ireland. Table 3.3, Table A1

Trends over time have not followed a uniform pattern. In 2003, mean BMI was similar in Scotland and England in both men and women. Rates of overweight including obesity, and obesity were also similar for men in both countries. Women in Scotland had higher rates of both overweight including obesity, and obesity, than women in England. The 1998 and 1995 surveys found higher rates of obesity among men in Scotland than England, but rates for women were similar.