Presentation on theme: "Challenges to tacking the obesity epidemic: Why public health approaches do not work Joe Proietto University of Melbourne Department of Medicine Repatriation."— Presentation transcript:
Challenges to tacking the obesity epidemic: Why public health approaches do not work Joe Proietto University of Melbourne Department of Medicine Repatriation Hospital Austin Health Heidelberg Victoria
“Common sense” tells us that obesity is caused by eating too much and not exercising enough. If so, the solution is clear and easy. To stem the obesity epidemic, we must simply educate the public about their eating and lifestyle behaviours.
From the “NorthEast & Region” Wednesday March 10 2004
The Minnesota Heart Health Program A 13 year research and demonstration program Included 3 demonstration communities and 3 matched control communities Primary end-point was reduction in cardiovascular risk achieved mainly by lifestyle modification leading to weight loss.
The Minnesota Heart Health Program Mass media campaigns were conducted for the duration of the program These media campaigns educated the people on: * the link between obesity and cardiovascular risk * behaviours that could contribute to the development of obesity * Services available to assist them with weight loss
Impact of education on body weight Cohort Study Jeffery RW et al. Int J Obes Relat Metab Disord 19:30-39 1995
Why did the public health measures in the Minnesota Heart Health Program fail to influence the weight gain? The Authors concluded that there were too many “negative” messages and that these overwhelmed the healthy messages.
What negative messages do we have? Australian children watch an average of 2.5 hours of television per day. Advertisements can occur at the rate of 30 per hour Food ads, as a percentage of total ads on television, range from 25%-48% (average 34%). (Hill and Radimer, 1997). Young Media Australia
A junk food advertising audit conducted by the Australian Divisions of General Practice National Divisions Youth Alliance in January 2003 analysed 50 hours of child targeted TV on commercial stations. Dr Andrew Binns Medicine Australia
Children watching two and a half hours of TV a day during the holiday period would have been exposed to 406 advertising messages encouraging them to eat junk food. Dr Andrew Binns Medicine Australia
What do you think the chances are of reducing this exposure to negative messages ?
Controlling food intake Can we reduce the exposure to negative messages? Probably over time Can we reduce the exposure of the population to energy dense food available in abundance all year round? Probably not
The World Today - Tuesday, 29 June, 2004 12:30:00 PM promises to spend on childhood obesity solutions Reporter: Alexandra Kirk The Prime Minister has promised to spend $116 million to tackle the problem of childhood obesity. Mr Howard said the plan was built on "common sense", as he called for support from the whole community to get children moving and eating well. Mr Howard has already rejected Labor's plan to ban fast food advertising during children's television programs, saying that would take responsibility away from parents.
Contribution of timetabled physical education to total physical activity in primary school children: cross sectional study Katie M Mallam,et al. BMJ 327:592-593 2003 Monitored physical activity during waking hours for 7 days using accelerometers in 3 schools. Studied 120 boys and 95 girls aged 7.5-10.5 years.
School 1 was wealthy with extensive facilities and 9.0 a week timetabled physical activity. School 2 was and award winning village school with 2.2 hours per week of timetabled physical education sessions. School 3 was an inner city school with limited or no sporting facilities and 1.8 hours timetabled physical education per week.
Conclusion “The total amount of physical activity done by primary school children does not depend on how much physical education is timetabled at school because children compensate out of school.”
Moodie ML, Carter RC, Swinburn BA, Haby MM. The cost-effectiveness of Australia's Active After-School Communities program. Obesity (Silver Spring). 2010 Aug;18(8):1585-92. Epub 2009 Nov 5. “For 1 year, the intervention cost is Australian dollars (AUD) 40.3 million (95% uncertainty interval AUD 28.6 million; AUD 56.2 million), and resulted in an incremental saving of 450 (250; 770) DALYs. The resultant cost-offsets were AUD 3.7 million, producing a net cost per DALY saved of AUD 82,000 (95% uncertainty interval AUD 40,000; AUD 165,000). Although the program has intuitive appeal, it was not cost- effective under base-case modeling assumptions.”
Reduced Physical Activity: 3 types of activity PastNow (5,000,000 BC -1800) (1800-2010) a) Obligatory + + + + - b) Voluntary + + c) Spontaneous + +
Long term effects of weight loss – diet therapy DietWeight loss 1-2 years Weight loss > 2 years Ad lib low fat-3.9 kg-2.7 kg Low energy-6.7 kg-1.1 kg Very low energy -11.8 kg-4.1 kg Meal replacement -5.5 kg-6.5 kg ‘Popular’ dietsNot known
Long term effects of weight loss – Physical activity Weight loss 1-2 years Weight loss > 2 years Physical activity - 1.8 kg- 1.3 kg Diet plus activity -7.5 kg- 3.1 kg
Long term effects of weight loss – Behaviour therapy Weight loss 1-2 years Weight loss > 2 years Behaviour therapy - 4.7 kg-2.8 kg
Long term effects of weight loss –Surgery Weight loss 1-2 years Weight loss > 2 years Gastric bypass - 46 kg- 42 kg Biliopancreatic bypass - 53 kg- 54 kg Non-adjustable gastroplasty - 41 kg- 25 kg Adjustable gastroplasty - 31 kg- 34 kg
WHY THESE RESULTS? Why is it that for most, the only therapy that works long term is the one that removes choice?
BMI- Intrapair Correlations TypeCorrelation Men Correlation Women Monozygotic Reared apart Reared Together 0.70 0.74 0.66 Dizygotic Reared Apart Reared Together 0.15 0.33 0.25 0.27 Stunkard AJ et al New Engl J Med 322:1483-7 1990
Twin A Twin B Abdominal Fat gain Effect of 100 days of overfeeding in 12 pairs of identical twins Bouchard C et al New Engl J Med 322:1477-82 1990
Prevalence (cont) 19802000 Obese BMI > 30 kg/m 2 7.1%18.4% Cameron AJ et al. MJA 178: 427-432 2003
Obesity is more prevalent among lower socioeconomic groups
How can these contradictory results be explained?
Obesity is more prevalent among lower socioeconomic groups
The current explanations are that: 1.There are more junk food outlets in underprivileged areas. 2.There is an inverse relation between energy density and energy cost. 3.The high energy density and palatability of sweets and fats are associated with higher energy intakes. However all of this ignores the intrinsic regulation of body weight
CONCLUSION 1 The Pessimistic view To overcome the powerful biological mechanisms causing and maintaining obesity we would need to recreate an environment where food is limited and physical activity is obligatory. Such a society is unthinkable in a free democratic country.
CONCLUSION 2 The optimistic view We will limit the obesity epidemic by identifying and avoiding the environmental (dietary) triggers to genetic obesity
UniMelb Obesity Austin Health –Weight Control ClinicPhysiotherapy Austin Health – Department of Respiratory MedicineRMH– Metabolic Disorders Clinic Australian Centre for Science, Innovation and Society Royal Women’s Hospital Bariatric Surgery (AH/ WH)School of Population Health - Key Centre Women's Health/Public Health Centre for Adolescent HealthSchool of Behavioural Science Centre for Meolecular, environmental, genetic and analytical epidemiology Centre for Community Child Health School of Nursing Centre for Health, Exercise and Sports Medicine SVH Hospital CSIRO Molecular & Health TechnologiesSt Vincents Institute Department of Economics Victorian Centre of Excellence for Eating Disorders Eating Disorders FoundationWalter and Eliza Hall Institute Faculty of Land and Food ResourcesWestern Hospital Obesity Clinic Mercy Hospital For Women Lymphoedema Clinic Metabolic Disorders Centre (A/H) Northern Hospital Healthy Eating Clinic Paediatric Obesity (RCH) Physiology