Childhood Obesity

Childhood Obesity Is it a growing problem? Dr Gerry McCartney Public Health Specialist Registrar NHS Greater Glasgow and Clyde

What is obesity? • Defined in adults using the ‘body mass index’ (BMI) – which is a function of weight and height • Obesity in adults is a BMI of greater than 30 (normal range is 20-25) • Children’s BMIs vary through the normal processes of growth, therefore a BMI cut-off at 30 is less relevant

Source: Scottish Health Survey; as presented on the Scottish Public Health Observatory website

How is obesity defined in childhood? • Current consensus is that obesity should be defined by comparing the distribution of BMI of today’s children with historic BMI distributions (from 1990) as the best proxy measurement • Using this measure, children who would have been amongst the 5% highest BMIs in the 1990 BMI distribution are considered obese

Source: ISD 2006; data extracted from child health systems project which takes data from 10 health boards (includes Greater Glasgow for preschool, but does not include Greater Glasgow for schoolchildren)

Source: CHSP: PS, ISD 2006

Proportion of pre-school children who are overweight by area Source: CHSP; PS – ISD 2006

Proportion of pre-school children who are obese by area Source: CHSP; PS – ISD 2006

Summary of the problem of childhood obesity • Prevalence of obesity is rising, both in the very youngest age groups and in adulthood • 21% of Scottish preschool children are overweight or obese and 31% of 3rd year secondary children • Obesity is associated with numerous health problems including diabetes, depression and cardiovascular disease • Obesity is a universal problem with slightly higher rates in more deprivation populations • Measuring trends in obesity is problematic as data is not routinely collected and obesity can be defined in a variety of ways

Causes of Obesity • Obesogenic environment • Readily available, cheap and heavily marketed energy rich foods • Increase in labour saving devices (lifts, remote controls etc) • Increase in passive and motorised personal transport (cars as opposed to walking, cycling or walking to public transport hubs) • Possible decrease in participation in active leisure pursuits in favour of passive activities (computers, television, reading)

Prevention or Treatment? • There are few evidence-based interventions which have been shown to be effective in the treatment of obesity, particularly in children • Primary prevention of obesity is therefore the preferable option if an epidemic of obesity and its resultant diseases is to be avoided

Current situation • A large amount of activity is ongoing both within the NHS and our partner agencies which aim to reduce obesity, but this work has not reversed the increasing obesity trend, although it may be tempering the rise • It is currently unclear where there may be gaps or overlaps in activity across the ‘obesogenic environment’

Evidence for obesity monitoring[NICE 2006] • No definitive method to monitor obesity in childhood • Current consensus is that BMI (combination of weight and height measures) compared with historic BMI distributions (from 1990) is the best proxy measurement • There is no evidence to support routine screening for obesity in children (or adults) • With the introduction of Hall4, there is now no routine monitoring of childhood obesity for NHS Greater Glasgow and Clyde

Evidence of obesity prevention[NICE 2006] • There is evidence that ‘upstream’ activities in the broad context of food policy, transport policy and urban planning is necessary to reverse the obesity epidemic (tackling the ‘obesogenic environment’) • There is a substantial body of evidence available to suggest that traditional health education techniques are ineffective in preventing obesity. • There is some evidence that pre-school interventions to improve diet or increase physical activity can be effective, but the evidence is weak and the effect small • The evidence to support ‘whole school approaches’ and ‘multi-component’ interventions is equivocal with some studies showing small positive effects and others showing no effect

There is some evidence that school meals policy could be a useful locus for intervention (eg Hull’s free school meals and Glasgow’s big breakfast), but that there is a current decreasing trend in school meal uptake in favour of cheaper ‘fast food’ options outwith the school gates • There is some limited evidence that interventions by health care professionals may have a role in the prevention of obesity, but this is largely based on studies in adults. • Interventions in the wider community have some evidence of positive effect, including measures to encourage active transport and public transport (eg. enhancing urban space for walking and cycling, reducing road space for cars, increasing subsidises for public transport and addressing safety concerns) • Health-orientated urban planning and architecture outwith the field of transport is also said to assist in reducing the ‘obesogenic environment’, such as housing built with high connectivity and building design that prioritises stairs and public transport use

Evidence for obesity ‘treatment’[NICE 2006] • The recommendations for children who present with obesity are based largely on expert opinion rather than robust evidence • The latest guidance suggests that obese children should be assessed for co-morbid features, and if these are found they should be referred to a specialist clinic for assessment and possible medical or surgical treatment • Patient pathways for childhood obesity are not clearly defined nor established in NHS Greater Glasgow and Clyde

Conclusions We are facing a growing problem with obesity in Scotland. ‘Treatment’ of obesity is fraught with difficulty Our priority should be to have comprehensive planning, policy and initiatives to reduce calorific intake and increase physical activity NHS Greater Glasgow and Clyde are developing a framework with our partners through the CH(C)Ps to create changes in the obesogenic environment

Childhood Obesity