The food industry must act to help bring about a major transformation in diet and activity needed to halt the rise in obesity and type two diabetes worldwide, the International Obesity TaskForce urged today (Monday August 25.)
Welcoming the publication of a new Atlas of Diabetes - for the first time incorporating an IOTF assessment of global levels of obesity - IOTF chairman Prof Philip James said the case for action to prevent the linked epidemics of overweight and diabetes was now irrefutable.
The Atlas, published by the International Diabetes Federation and launched at the International Diabetes Congress in Paris, provides a graphic demonstration of the significant global challenge which threatens to devastate the health of many people in the developing world at a time when their countries were set to see major economic advances, he added.
"The case for action on diet and activity is irrefutable and the recommendations made in the World Health Organization's recent report on nutrition and the prevention of chronic diseases should be incorporated into a robust global strategy aimed at turning back the tide of non-communicable diseases. Governments throughout the world should be making this a top priority," he said.
He said that the food and drinks industries were beginning to recognise the signficance of the global challenge but had yet to face up to their responsibility to improve nutritional health. "They must do a lot more than just form advisory councils to do a PR job on their image. They must sit down seriously to work out how they can help meet the urgent need to reduce the high fat, sugar and salt content in a lot of the every day processed foods we consume so we can transform the dietary health of the world and in doing so help stem the increasing burden of weight-related disease such as type 2 diabetes."
The WHO 916 report on diet, nutrition and the prevention of chronic diseases was published in April after opposition from some elements within the food industry. It recommends that no more than 30% of calories should come from fat, no more than 10% from sugar and salt should be reduced to achieve a maximum intake for adults of 5 gms per day.
The IOTF estimates that more than 1.1 billion people are overweight or obese, but overall almost 1.7 billion are at risk of a range of weight-related illnesses which include type 2 diabetes, heart disease and some common cancers. The International Diabetes Federation estimates that there are 190 million people with diabetes and this is forecast to increase to 330 million by 2025.
Note - The Atlas of Diabetes is being launched at the 18th IDF Congress on Diabetes in Paris on Monday August 25. See http://www.idfparis2003.org/
For media inquiries regarding obesity contact:
Neville J Rigby, Director of Policy and Public Affairs
IASO/International Obesity TaskForce
mobile +44 7939250347web: www.iotf.org/media
Obesity is the principal risk factor for type 2 diabetes. It involves an excess of body fat, which, especially when concentrated within the abdomen, has a range of potentially harmful consequences. Classified as a disease, obesity diminishes both quality of life and life expectancy, but it is also a common risk factor for a number of other diseases from osteo-arthritis to heart disease and some types of cancer.
The World Health Organization defines overweight as a body mass index (BMI) of at least 25 kg/m2 and obesity as a BMI of at least 30 kg/m2. However the health risks of increased body fat rise progressively above BMI levels of 20-22 kg/m2 in all populations.(1)
The conclusions of a WHO expert group, which considered the evidence for lower BMI action points in different Asian populations, are at present under review. The WHO recommends a limit for waist circumference of 102cms and 88cms in men and women, but more appropriate waist circumference action levels are now being
sought to specify risk levels relating to diabetes and other factors in Asian countries to help alert those with lower BMIs to their increased risks. (2)
Over recent years rates of overweight and obesity have escalated rapidly to epidemic proportions in many parts of the world, reflecting increasing consumption of energy dense diets high in fats and sugars, compounded by declining levels of physical activity. Using the standard classification, more than 1.1 billion are estimated to be overweight, of whom around 320 million are now calclulated to be obese. The IOTF estimates that up to 1.7 billion people may be exposed to weight-related health risks, taking into account varied Asian populations with a BMI of 23 or more. Average BMI levels across Africa and Asia have been estimated at between 20-23 kg/m2, but in Europe and North America mean levels are much higher at 25-27 kg/m2, indicating that a substantial part of the population may be exposed to the health risks of higher BMIs.(3)
Regional trends
Across the world the epidemic of obesity has been gathering momentum affecting both developed and developing countries.
Europe - Few countries report obesity rates below 10%. Prevalence rates, particularly among women, rise to more than 20% in countries such as the United Kingdom, Germany, Finland and Greece. The most rapid increase is noted in England where
that obesity rates have risen three-fold from 1980 to 2001, with levels of morbid obesity (BMI>40) also increasing three-fold among men and almost double among women during the 1990s.(4)
North America - In the United States obesity is a marked phenomenon affecting one in three adults, more than double the rate of 20 years ago. Ethnic minorities are affected disproportionately with 40% of Mexican American women and 50% of
black American women having a body mass index above 30 kg/m2. Extreme obesity rates, classified as morbid obesity of BMI>40, are as high as 15% among black American women.(5)
Neighbouring Canada experienced an increase of 150% in its overall adult obesity rate from 1985 to 1998 reaching 14.8%. (6)
Latin America and Caribbean - Evidence of the impact of the nutritition transition is clear in the growing levels of obesity throughout this region. Obesity rates are reported to vary for men from 7% in Peru and Brazil to more than 20% in
Paraguay, but among women rates rise as high as 36% in Paraguay.(7)
In the Caribbean, obesity is a significant problem, particularly among women, with correspondingly high rates of type 2 diabetes. Abdominal obesity, using WHO waist
circumference limits, ranged from 3% of men in St Lucia to 8% in Barbados, but among women was found to be as high as 34% in Jamaica, 41% in St. Lucia, and 45% in Barbados.(8)
Diabetes studies in Jamaica have demonstrated markedly high risks
associated with overweight and central obesity.(9)
Africa - Wide disparities in levels of obesity are found with the highest rates in South Africa, where mean BMI values for men and women are 22.9 kg/m2 and 27.1 kg/m2 respectively, but levels of central obesity among women have been assessed at 42%.(10) The South Africa Health Review 2000 indicated obesity rates from 8% among black men to 20% among white men, but among women the rates range from 20% for Indian/Asians to 30.5% for black women. In North Africa the prevalence of obesity among women is high. Half of all women are overweight (BMI>25) with rates of 50.9% in Tunisia and 51.3% in Morocco, and obesity rates (BMI>30) in women of 23% in Tunisia and 18% in Morocco, a three fold increase over 20 years.(11)
In parts of sub Saharan Africa obesity often exists alongside undernutrition.(12)
Middle East - High levels of obesity exist particularly among women, but often men too, in many countries as diverse as Egypt, the Gulf states including Saudi Arabia. Obesity rates of 25-30% and even higher are not untypical in Kuwait, the United Arab Emirates, Bahrain. In Iran obesity rates vary from rural to urban populations rising to 30% among women in Tehran.
Asia - Various Asian populations may be particularly susceptible to the health risks of central obesity, regardless of BMI.(13) Consequently there is an increasing focus on measuring waist circumferences, which can predict individual risk more accurately than body mass index. However in Japan experts have agreed independently to redefine the obesity cut-off at BMI>25 and have suggested this apply in the Asian Region. Using this standard, adult obesity in Japan would average 20%, rising to 30% in men over 30 years old, and in women over 40 years old, representing a three to four fold increase over the last 40 years.(14)
China has adopted its own standards defining overweight at a BMI of 24 or more, and obesity and BMI of 28 or more. However abdominal obesity is defined by a waist circumference of 85 cm in men and 80 cm in women.(15)
Pacific - The link between obesity and type 2 diabetes is most manifest in this region which has some of the highest levels of adult obesity. Obesity prevalence rates of between 60 to 80 % can be found among men and women in some islands including Samoa and Nauru. In Tonga 60% of the adult population is obese and recently 12% of men and nearly 18% of women were identified with type 2 diabetes, a doubling of the rate over 25 years. A further 20% were found to be at risk due to elevated blood sugar levels. (16)
Obesity and type 2 diabetes are causally linked. Weight gain leads to insulin resistance, through several mechanisms. Insulin resistance places a greater demand on the variable pancreatic capacity to produce insulin, which itself declines with age, leading to the development of clinical diabetes.
Fat accumulation itself induces insulin resistance through changes in its hormonal and other secretions. Metabolically toxic secretions increase while protective hormones such as adiponectin decline as fat cells increase, particularly where concentrated in the abdomen. Physical inactivity, both a cause and consequence of weight gain, also contributes to insulin resistance.
The IOTF analyses, undertaken for the World Health Report 2002,and associated WHO Global Burden of Disease research, indicate that approximately 58% of diabetes mellitius globally (as well as 21 % of ischaemic heart disease and 8-42% of
certain cancers) can be attributed to BMI above 21 kg/m2. However in Western countries, around 90% of type 2 diabetes cases are attributable to weight gain, (see Figure 1) and childhood overweight and obesity now leading to an unusual pattern of premature type 2 diabetes, which is particularly difficult to manage once established.(17)
Among adults, clear evidence exists that weight loss can reverse the type 2 diabetic state and surprisingly modest weight reductions can markedly reduce the development of diabetes if not prevent it completely in susceptible individuals. The remarkable effect of weight loss through diet and increased activity has been demonstrated in the USA's National Institute of Diabetes and Digestive and Kidney Diseases Diabetes Prevention Programme to benefit particularly the over 60s, in whom nearly three quarters of new cases of diabetes were prevented.(18)
This and other studies provide hope to those with impaired glucose tolerance and a susceptibility to diabetes. Dietary and activity changes to produce a 5-7 % weight loss can successfully reduce the incidence of type 2 diabetes; reductions in fat and calorie intake accompanied by half an hour's extra walking or other exercise each day lowered the incidence by 58 %. Great success has been achieved among people over 60 years, reducing the development of diabetes in that high risk age group by 71%. Similar data have emerged from China, Scandinavia and other European studies.
The cost of obesity can be identified both in economic terms, but also in terms of years of disability which reduces the quality of life as well as lowering life expectancy. Higher body mass index has been shown to account for up to 16% of
the burden of disease, expressed as a percentage of disability-adjusted life years (DALYs).(19)
In several developed countries obesity has been estimated to account for 2-7% of the total health care costs. (20)
Recently the combined direct and indirect costs to the USA have been re-assessed at $123 billion in 2001.(21)
This expenditure may overshadow the costs in smaller countries such as England where the Parliamentary National Audit Office assessed the cost at around £2.5 bn (£3bn when adjusted to 2003 figures). In the Pacific Islands, the economic consequences of non-communicable diseases, chiefly obesity and type 2 diabetes, have been dramatic, consuming US$1.95m - almost 60% - of the health budget of Tonga, and US$13.6m - 39% - of the health budget of Fiji.(22)
Childhood obesity is a relatively recent phenomenon, which poses a critical global health crisis. Significant prevalences have been identified in developing countries as well as in industrially developed economies. An IOTF analysis has shown that overweight and obesity affects one in 10 children worldwide, but the rate is double in Europe and three times as great across the entire Americas.(23)
The emergence of type 2 diabetes in childhood is a serious development. In the USA it has been noted that up to 45% of children with newly diagnosed diabetes have type 2 diabetes and most are overweight or obese at diagnosis.(24)
CONCLUSION
The most recent WHO recommendations for dietary improvements and increased levels of exercise across entire populations provide the basis for the development of global strategies to challenge the rise in obesity along with other diet and activity related chronic diseases, including type 2 diabetes.(25)
However were the WHO recommendations, including those to
reduce fat, sugar and salt consumption, to be implemented, it would be some
considerable time before the benefits were reflected in a reduction of obesity
and co-morbidity rates. A new generation is entering adulthood with
unprecedented levels of obesity. This, in addition to the existing burden of
adult obesity, and the continuing rapid escalation of childhood obesity and
earlier onset of type 2 diabetes, reinforces the concern that weight-related
chronic diseases will be the most significant public health concern throughout
the 21st century. The provision of effective obesity therapies, which can
prevent or delay the onset of type 2 diabetes, and the development of coherent
strategies to halt the progressive weight gain in evidence in most populations,
is lacking. Weighing the clear benefit
of interventions against the significant costs in both human and financial
terms of inaction, it is surprising, if not alarming, that so little has been
done worldwide to attack the root causes of the twin epidemics of obesity and
type 2 diabetes.
© IOTF,
London. 2003
References:
1
Obesity: Preventing and Managing the Global Epidemic WHO TRS 894 2000
2
WHO Expert Consultation on Asian Anthropometric Measurements Singapore June
2002 - see Lancet Lancet Vol 360 July 20 2002
3
IOTF analysis of data gathered for the WHO Global Burden of Disease 2003
4
IOTF database/England: 6% men 8% women 1980: 21% men 23.5% women 2001. Health
Survey for England
5
NHANES 1999-2000
6
Katzmarzyk PT The Canadian Obesity
Epidemic 1985-1998 JAMC 16 Apr 2002 1 66 (8)
7
Filozof et al Obesity prevalence and trends in Latin-American countries Obesity
Reviews Volume 2 Issue 2 Page 99 - May 2001
8
Okosun et al. Abdominal adiposity in six populations of West African descent:
prevalence and population attributable fraction of hypertension.Obes Res 1999 Sep;7(5):453-62
9
Wilks R et al Diabetes in the Caribbean: results of a population survey from
Spanish Town,Jamaica Diabet Med 1999
Oct;16(10):875-83
10
Puoane et alObesity in South Africa: the South African demographic and health
survey. Obes Res 2002
Oct;10(10):1038-48
11 Mokhtar N et al Diet Culture and Obesity in Northern Africa Journal of Nutrition.
2001;131:887S-892S. Supplement
12
Maire B et al Urbanization and nutritional transition in sub-saharan Africa:
exemplified by Congo and Senegal - Rev Epidemiol Sante Publique
1992;40(4):252-8
13
James et al Appropriate Asian body mass indices? Obes Rev 2002 Aug
14
Kanazawa et al Criteria and classification of obesity in Japan and
Asia-Oceania. Asia Pac J Clin Nutr 2002
Dec;11 Suppl 8:S732-S737
15
Zhou BF; Cooperative Meta-Analysis
Group of the Working Group on Obesity in China. Predictive values of body mass
index and waist circumference for risk factors of certain related diseases in
Chinese adults--study on optimal cut-off points of body mass index and waist
circumference in Chinese adults. Biomed
Environ Sci 2002 Mar;15(1):83-96
16
Colagiuri et al The prevalence of diabetes in the kingdom of Tonga.Diabetes
Care 2002 Aug;25(8):1378-83
17
James et al. Chapter: Overweight and obesity in Ezzati M, Lopez AD, Rodgers A,
Murray CJL. Comparative Quantification of Health Risks: Global and Regional
Burden of Disease Attributable to Selected Major Risk Factors. Geneva: World
Health Organization, 2003 in press
18
Knowler et al Diabetes Prevention Program Research Group. Reduction in the incidence of type 2
diabetes with lifestyle intervention or metformin. N Engl J Med 2002 Feb 7;346(6):393-403
19
WHO World Health Report 2002/ IOTF research see for the WHO Global Burden of
Disease programme. See Ref 16
20
Obesity: Preventing and Managing the Global Epidemic WHO TRS 894 2000
21
Wolf A. Revised estimate. University of Virginia 2003
22
Dalton A and Crowley S. Economic impact of NCD in the Pacific Islands in Obesity
in the Pacific: Too Big To Ignore. Secretariat of the Pacific Community 2002
23
IOTF - Childhood Obesity - The New Crisis In Public Health. International
Obesity TaskForce, London 2003 (in press)
24
Type 2 diabetes in children and adolescents. American Diabetes Association
Diabetes Care Vol 23, No 3, 2000
25
WHO/FAO: Diet, Nutrition and the Prevention of Chronic Diseases WHO TRS 916
Geneva 2003
(http://www.who.int/hpr/NPH/docs/who_fao_expert_report.pdf)