School-based healthy lifestyle interventions alone are not effective in the fight against childhood obesity, researchers at the University of Birmingham have warned.
The warning comes after one of the largest childhood obesity prevention trials undertaken to date has found that a healthy lifestyle intervention carried out in dozens of schools did not lead to significant changes in pupils' weight.
Led by the University of Birmingham, the West Midlands ActiVe lifestyle and healthy Eating in School children (WAVES) study was a trial funded by the National Institute for Health Research (NIHR). It aimed to assess the clinical and cost-effectiveness of a programme of activities designed to support children aged six and seven in keeping their weight at a healthy level by promoting healthy eating and physical activity.
Excess weight in childhood is a global problem, affecting around 41 million children under the age of 5 years1. In addition to physical and psychosocial health consequences in these early years, childhood excess weight is an important predictor of obesity in adulthood2, with additional adverse health and economic3 effects. In the UK around a quarter of children have excess weight at school entry (age four to five years)4. The proportion of very overweight children doubles during the subsequent six years (from approximately 9% to 19%)4, highlighting this time period as critical for preventive action.
The 12-month WAVES study intervention included a daily additional 30 minute school-time physical activity opportunity, and a six-week interactive skill based programme in conjunction with a premiership football club. It also included signposting of local family physical activity opportunities through six-monthly mail-outs and termly school led family healthy cooking skills workshops.
Almost 1,500 pupils from 54 state primary schools in the West Midlands took part in the trial. Their measurements - including weight, height, percentage body fat, waist circumference, skinfold thickness, and blood pressure - were taken when they started the trial. They also wore an activity tracker for five days, recorded their dietary intake and took part in assessments to establish their perceived quality of life, social acceptance and body image. These measurements were taken again 15 months and 30 months later and were compared among pupils who were or were not taking part in the intervention.
The results of the randomised controlled trial, published today in The BMJ, found that the intervention did not result in a significant difference in participants' weight status.
Professor Peymané Adab, of the University of Birmingham's Institute of Applied Health Research, said: "Our research, combined with wider evidence, suggests that schools cannot lead on the childhood obesity prevention agenda."
Dr Miranda Pallan, also of the University of Birmingham's Institute of Applied Health Research, added: "Whilst school is an important setting for influencing children's health behaviour, and delivery of knowledge and skills to support healthy lifestyles is one of their mandatory functions, widespread policy change and broader influences from the family, community, media and the food industry is also needed."
The research team added: "although wider implementation of this WAVES study intervention cannot be recommended for obesity prevention, the lower cost components could in the future be considered by schools to fulfil their mandated responsibilities for health and wellbeing education."
For further information or interviews contact Emma McKinney, Press Office, University of Birmingham, at +44 (0)121 414 6681 or contact the Press Office out of hours on +44 (0)7789 921165.
1. World Health Organization. Commission on Ending Childhood Obesity. Report of the Commission on Ending Childhood Obesity. Geneva, 2016.
2. Serdula MK, Ivery D, Coates RJ, et al. Do obese children become obese adults? A review of the literature. Prev Med 1993;22(2):167-77.
3. Withrow D, Alter DA. The economic burden of obesity worldwide: a systematic review of the direct costs of obesity. Obes Rev 2011;12(2):131-41. doi: 10.1111/j.1467-789X.2009.00712.x [published Online First: 2010/02/04]
4. Lifestyles Statistics Team HaSCIC. National Child Measurement Programme: England, 2014/15 school year, 2015.
NOTES TO EDITORS
The University of Birmingham is ranked amongst the world's top 100 institutions. Its work brings people from across the world to Birmingham, including researchers, teachers and more than 5,000 international students from over 150 countries.
Adab et al (2018). 'Effectiveness of a childhood obesity prevention programme delivered through schools, targeting 6-7 year old children: the WAVES study; a cluster-randomised controlled trial'. BMJ.
WAVES study trial investigators:
University of Birmingham: Peymane Adab (Professor of Public Health and Chief Investigator), Tim Barrett (Professor of Paediatrics), KK Cheng (Professor of Public Health and Primary Care) Amanda Daley (Reader in Behavioural Medicine), Jonathan J Deeks (Professor of Biostatistics), Joan L Duda (Professor of Sport and Exercise Psychology), Emma Frew (Reader in Health Economics), Karla Hemming (Senior Lecturer in Medical Statistics), Miranda J Pallan (Senior Clinical Lecturer), Jayne Parry (Professor of Policy and Public Health).
University of Warwick: Paramjit Gill (Clinical Reader in Primary Care Research).
University of Cambridge, Cambridge MRC Epidemiology Unit / Norwegian School of Sport Sciences: Ulf Ekelund (Professor of Physical Activity Epidemiology and Public Health/Senior Investigator Scientist).
University of Leeds: Janet E Cade (Professor of Nutritional Epidemiology and Public Health).
The University of Edinburgh: Raj Bhopal (Bruce and John Usher Chair in Public Health).
Birmingham Community Healthcare NHS Trust: Eleanor McGee (Public Health Nutrition Lead).
Birmingham Services for Education: Sandra Passmore (Education Advisor).
The WAVE study comprised of four overlapping components:
- 1. 30 minutes of additional moderate to vigorous physical activity on each school day - at least 15 minutes to be outside of break.
2. Termly school-time cooking workshops which parents were invited to attend to participate alongside their child and that were preceded by short classroom sessions for the children.
3. A six-week programme (Villa Vitality (VV)) developed to encourage healthy eating and increase physical activity and delivered by staff from Aston Villa Football Club. School classes spent two days undertaking activities (indoor based movement routines and dance mats, ball skills-session, interactive nutritional sessions and opportunity to practice cooking skills) at the Club, separated by a six-week period during which class teachers were asked to spend curriculum time working on a class project and involving children and their parents with weekly health challenges.
4. Information sheets signposting children and their families to ways to be active over the summer and physical activity opportunities in their local area.
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