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  • Overweight

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      This EUphact has been peer reviewed by two reviewers.

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      Authors, editors and reviewers

      19 March 2007
      Overweight
      Summary

      Overweight and obesity are important health risks

      Overweight and its more serious form, obesity, refer to the condition in which excess fat has accumulated in the body. This is caused by consuming more calories than the body needs. The problem is largely due to our ‘obesogenic’ environment. Overweight and obesity are important risk factors for a range of diseases and disorders. Obesity is an important risk factor for cardiovascular disease, type 2 diabetes mellitus, certain cancers and osteoarthritis. Other conditions associated with obesity are infertility among women, mental problems such as depression and low self-esteem and sleep apnoea. Due to the growing problem of obesity, an increase in obesity-related morbidity and mortality is expected in the future.

      Considerable variations in overweight prevalence among adults

      The proportion of adults who are obese in the EU-25 ranges from less than 10% in Italy to more than 20% in Cyprus, Czech Republic, England, Germany, Hungary, Scotland (UK) and Slovakia. The proportion of adults who are overweight (including those who are obese) ranges from 36% of French women to more than 75% of German men. In all countries the prevalence of overweight is higher among men than among women, but obesity is generally higher among women than in men. There is clear evidence of increasing trends in overweight and obesity in the EU.

      Childhood obesity is accelerating in many EU-countries

      Childhood obesity is an epidemic in some EU-countries. Some southern European countries report overweight (including obesity) levels exceeding 30% among children aged 7-11. Rates of increase vary, with England and Poland showing the steepest increases. The epidemic of childhood obesity and overweight is accelerating in the EU.

      An inverse association between obesity and socio-ecomic status

      In many EU-countries there is a clear inverse association between obesity and socio-economic status. Especially in women, the prevalence of obesity is higher among low educated than among high educated people.

      Some interventions have proven to be effective

      Some prevention strategies linked to behaviour, diet and exercise have proven to be effective to a certain extent. However, maintenance of interventions is necessary to sustain weight loss. Surgery may help people with severe obesity.

      Environmental interventions attempt to affect behavioural changes by modifying the external surroundings. The aim of such interventions is to prevent weight gain, without exclusive reliance on an individual’s knowledge or motivation. Many environmental factors have been cited as contributing to obesity. Still, there have been few controlled studies showing that changes in these factors will prevent weight gain.


      11 April 2008
      Overweight
      Definition and scope

      Overweight and obesity can be measured in different ways

      Overweight and obesity refer to the condition in which excess fat has accumulated in the body. This condition is a risk factor for a range of diseases and disorders. The extent of overweight is determined in various ways.

      The most common method of determining weight status is Body Mass Index (BMI). This measure relates an individual’s weight to his or her height. According to the WHO classification, individuals with a BMI between 25 and 30 are defined as overweight and those with a BMI equal to or over 30 as obese (see Table 1).

      Abdominal skinfold measures, Waist-to-Hip ratio (WHR) and waist circumference are considered to be markers of central obesity or intra-abdominal fat. Waist circumference in combination with BMI has shown to be the best descriptor of obesity and predictor of health risks. A waist size greater than 102 cm for men and 88 cm for women increases the risk for most weight-related illnesses.

      Other methods for measuring body fat include using electronic impulses, water tank submersion, scanning techniques such as computed tomography (CT) or magnetic resonance imaging (MRI) and special scales. These newer techniques, although providing more precise measures of body fat, are costly and impractical for use in large epidemiological studies or in population surveys (WHO, 2000d; Kuller, 1999).

      In this EUphact, overweight and obesity are described in terms of BMI.

      Table 1: Classification of Overweight and Obesity by BMI (WHO, 2000).

      Obesity class

      BMI (kg/m2)

      Underweight

      <18.5

      Normal

      18.5 - 24.9

      Overweight

      25.0 - 29.9

      Obesity

      I

      30.0 - 34.9

      II

      35.0 - 39.9

      Extreme Obesity

      III

      ≥40

      Limitations of BMI as a measure of overweight

      BMI is considered to be the most appropriate measure of overweight and obesity prevalence on a population level. Read here about the detailsLimitations of BMI as a measure of overweight and obesity.


      8 June 2009
      Overweight
      Occurrence

      Prevalence of overweight and obesity varies widely within the EU

      The proportion of adults who are obese in the EU-25 ranges from less than 10% in Italian women to more than 25% in Czech women. The proportion of adults who are overweight ranges from 23.3% of French women to 53% of German men (see TablePrevalence of overweight and obesity in European countries). In all EU-countries the prevalence of overweight is higher among men than among women. In most countries obesity is more frequently present among women than among men. No gradient in the prevalence of overweight can be distinguished.

      Prevalence rates of overweight and obesity in populations are often obtained in samples with different age distributions and in different time periods. Precisely comparable prevalence rates are rare, and international comparisons should be interpreted with caution.

      The ISARE project has collected data on obesity at subnational level. These data ar shown in MapPrevalence of obesity in selected ISARE health regions.

      Number of overweight people has increased in the EU

      The percentage of people with overweight or obesity has increased in the EU, as well as in the rest of the world. The WHO talks of the "global epidemic of obesity" (WHO, 2003b). Trend data suggest an increase in obesity rates in almost all countries. Even in those countries with relatively low rates of obesity, such as France and Denmark, there is clear evidence of an increase. In France, obesity in women rose from 8% to 13% while in men it rose from 8.4% to 11.8% between 1997 and 2006 (self reported data). In the Netherlands obesity among men rose from 4.9% to 8.5%, while for women it went from 6.2% to 9.3% from the late 1970s to the mid-1990s (measured data). In the UK (England), the annual health survey has recorded dramatic increases in measured obesity from 13% to 22.7% in men and 16% to 23.8% in women, in just 10 years, until 2004. This compares with an obesity prevalence of 6-7% in 1980 (IOTF, 2005b).

      Childhood obesity is turning into an epidemic

      Childhood obesity is already an epidemic in some European countries and on the rise in others (WHO, 2003b). In 2004 it was estimated that 14 million school-age children in the EU were overweight, including three million obese children. These estimates were made using the IOTF standard definition for international data comparisons (IOTF, 2004).
      Recently, two papers on overweight and obesity prevalence in European children have been published, involving at least 10 countries (Lobstein & Frelut, 2003; Lissau et al., 2004). The findings of these studies and differences in data collection used are described in detailsPapers on childhood overweight.

      Childhood obesity epidemic is worsening

      Most publications on childhood obesity agree that the epidemic of childhood obesity and overweight is accelerating. An analysis of survey data conducted throughout Europe since the mid-1970s, reveals a rapid shift in the trend during the mid-1990s (IOTF, 2006). The number of children affected by overweight and obesity is now rising at more than 400,000 a year and already affects almost one in four across the entire EU. The new prevalence of 24% in 2002 is five points higher than had been expected based on original trends in the 1980s and is already higher than the predicted peak for 2010 (IOTF, 2006).

      There is a clear socio-economic gradient in most EU-countries

      In many EU-countries there is a clear socio-economic gradient in obesity (Rahkonen et al., 1998; Stam-Moraga et al., 1999; Hulshof et al., 2003; Molarius et al., 2000; Eurothine, 2007). Especially in women, a strong inverse association between obesity and socio-economic status, mostly assessed by educational level, has been reported in many EU countries. This means that obesity among women with lower education levels is more prevalent than among highly educated women.For the WHO-MONICA study, 26 mostly European populations were monitored over a 10-year period (Molarius et al., 2000). Lower education was associated with higher BMI in about half of the male and in almost all of the female populations, and the differences in relative body weight between educational levels increased over the study period (for both, men and women). For women in the MONICA project, the results of the final measures were similar to those in the initial survey (1979-1989). For men, the proportion of population having a significant inverse association increased from 23% in the initial survey to 50% in the final survey. Poland is the only EU country in which a significant positive association was found in one of its regions

      See also: EUphocus Health inequalities.


      28 April 2008
      Overweight
      Consequences for individual and society

      Obesity is a key risk factor for a number of diseases

      Although obesity could be considered a disease in its own right, it is also a key risk factor for a number of chronic diseases that constitute the principal causes of death in the EU. Obesity, especially central obesity, is an important risk factor for cardiovascular disease (CVD), type 2 diabetes mellitus and certain cancers. Overweight and obesity contribute significantly to osteoarthritis, a major cause of disability in adults.

      Other conditions associated with obesity are infertility among women, mental problems such as depression and low self-esteem and sleep apnoea.

      Obesity and type 2 diabetes mellitus: a close relationship

      One of the consequences of weight gain is insulin resistance, which can result in type 2 diabetes mellitus. Obesity, in particular abdominal obesity, is the most important risk factor for the onset of diabetes. Compared with the lowest BMI category, risks for developing type 2 diabetes mellitus are increased more than tenfold among women with BMIs higher than 29 kg/m2 and among men with BMIs higher than 31 kg/m2 (Carey et al., 1997; Visscher & Seidell, 2001). Being moderately overweight is also closely related to the onset of type 2 diabetes mellitus. About 64% of type 2 diabetes in North-American men and 74% in North American women could be avoided if there were no BMIs above 25 kg/m2 (WHO, 2000; Visscher & Seidell, 2001). See also the EUphocus Diabetes prevention and care.

      Overweight is related to several cancers

      Overweight, in particular obesity is related to the incidence of some cancers. The strongest evidence is for cancer of the endometrium. A BMI exceeding 30 kg/m2 is associated with a one and a half to three times higher risk of developing endometrial cancer than a BMI between 20 and 25 kg/m2 (WCRF, 1997; Visscher & Seidell, 2001). The WCRF classifies the relationship between high BMI and breast and kidney cancer as “probable”, with approximately 1.8-fold higher risk for those with a BMI exceeding 27 kg/m2 compared with those having a BMI below 17 kg/m2. Furthermore, there is evidence of a possible relationship between high BMI and colon cancer. This relationship is more consistent for men than for women. Gallbladder cancer is possibly associated with high BMI, particularly for women.

      A possible mechanism for the relationship between high body weight and cancer is based on the metabolic abnormalities (metabolic syndrome) that result from high BMI levels (Visscher & Seidell, 2001).

      Effects of overweight on cardiovascular health

      The effects of obesity on cardiovascular disease are manifold. Hypertension is probably one of the most common ones. Blood pressure increases with the increase of BMI, and people who are obese have been found to have a much higher prevalence of hypertension (AIHW, 2004).

      See also detailsEvidence for the relation between excess body weight and Cardiovascular Disease.

      Relative risk highest for women with obesity

      An overview of relative risks for diseases associated with obesity is presented in TableEstimated increased risk for the obese of developing associated diseases. The data are extracted from The National Audit Office (NAO) in England (NAO, 2001). A more extensive overview of relative risks for the different BMI levels is given in the report ‘Our food, our health - Healthy diet and safe food in the Netherlands’ (Kreijl et al., 2006). Based on international literature, risks have been estimated for different age classes, both sexes and different levels of overweight. From this overview it becomes clear that morbidity is elevated in overweight people and that it is higher in obese people than in overweight people. This is particularly true of type 2 diabetes, but also holds for cardiovascular diseases, gallbladder diseases, conditions which impaired mobility (such as osteoarthritis), and various forms of cancer.

      Indirect costs of obesity are far greater than direct costs

      The direct costs of obesity are now estimated to be around 1% - 5% of total health care costs in Europe, compared to 7% (or US$ 70 billion) in the United States (Colditz, 1999; Seidell, 1995).
      Indirect costs, which are far greater than direct costs, include work days lost, physician visits, disability pensions and premature mortality.

      Narbro calculated that approximately 10% of the total costs of the productivity losses due to sick leave and work disability may be attributable to obesity-related diseases (Narbro et al., 1996). Due to the increase in prevalence and costly consequences, obesity is now being recognised not only as a risk factor in the clinical setting but also as an important threat to public health. The public health impact of obesity should be measured by its combined effect on disability and mortality. Intangible costs such as impaired quality of life are also enormous.


      19 March 2007
      Overweight
      Causes and risk factors

      An imbalance between energy consumption and energy expenditure

      Weight gain, overweight and obesity are caused by consuming more calories than the body needs, usually by eating a diet high in fat and calories, living a sedentary lifestyle or both. The environments most people in the EU live in are increasingly obesity-favourable (“obesogenic”). There is often no need to be physically active and the availability of energy-rich food is overwhelming.

      It is impossible to establish a direct causal link between environmental/cultural factors and the rise in obesity levels, but there are obvious associations between changing environments and increasing waistlines (Royal College of Physicians, 2004).

      Evidence of factors that promote or protect against overweight

      Based on a comprehensive review of evidence for the dietary causes of obesity, Swinburg and colleagues pointed out a number of factors that might promote or protect against overweight or weight gain (Swinburn et al., 2004). The evidence was classified as: convincing, probable, possible and insufficient. The results of the review are presented in detailsEvidence of factors that might promote or protect against overweight or weight gain.

      Major shifts in eating and physical activity patterns

      The way in which work and leisure time are spent has changed, resulting in a major shift in eating and physical activity patterns:

      • Jobs are more sedentary;
      • Labour saving devices (lifts, remote controls) have reduced daily activity levels;
      • Screen based entertainment (TV, computer) has increased;
      • Less time is spent preparing meals and more processed food is consumed;
      • Eating out and snacking and grazing are more common;
      • Alcohol intake has increased, especially among young people.

      Food advertised to children often less healthy than recommended

      Food marketing and advertising reflect heavy investment and great sophistication, and permeate all levels of society. Research in the UK reveals that ninety per cent of food advertising screened during children’s broadcasts is for foods high in fat, salt and/or sugar (Royal College of Physicians, 2004). A review of the effects of food promotion to children concluded:

      • Food advertising to children is extensive;
      • The diet being advertised is less healthy than the recommended diet for children;
      • Children enjoy and engage with food promotion;
      • Food promotion is affecting preference, purchase behaviour and consumption;
      • The effect is independent of other factors and operates at both brand and food category level.

      Overweight is not only related to food intake and physical activity

      The imbalance between calories consumed and calories burned can also be caused by other obesity-related factors. For instance, metabolism, hormones that affect the way calories are processed, and other organ systems in the body can all affect appetite or the way in which the body stores the extra energy.

      As with many conditions, obesity is a result of combined influences of genetic and environmental factors. Some genetic abnormalities that predispose to obesity have been identified, but these are absent in most people with obesity.


      19 March 2007
      Overweight
      Interventions

      It is difficult to prevent and treat overweight and obesity

      Most population-based prevention programs that have been scientifically assessed have not demonstrated any favourable effects on the prevalence of obesity. However, there are examples of successful programs for both adults and children.

      According to the Swedish systematic review of interventions (Asp et al., 2002), scientific assessments of treatment methods for obesity show that:

      • Changes in dietary habits through counselling can lead to weight reduction in the range of 3 to 10 kg during the first year (or 10% of body weight in children). The long-term effects are uncertain.
      • Regular exercise contributes to weight reduction.
      • Behavioural therapy in conjunction with changes in diet and exercise can have further effects on weight if supportive interventions continue for a longer period.
      • Treatment based on the ‘Weight Watcher’ approach often results in a permanent weight loss of 10% or more of their original weight.
      • VLCD for 6 to 12 weeks yields a greater weight reduction than conventional low energy diets. In studies of VLCD for 1 to 2 years (often periodic), a retained weight loss of a few kilograms more than in treatment using a balanced diet alone was noted.
      • Pharmacological treatment using orlistat (Xenical®) or sibutramine (Reductil®) yields an average weight loss of 2 to 5 kg beyond what would be attained through diet and exercise alone. In clinical trials, one fourth to one fifth of those who started pharmacological treatment lost at least 10% in weight compared to half as many of those treated with placebo.
      • The scientific evidence for a wide range of alternative medicine methods is too weak to draw any conclusions concerning the possible effects these methods have on obesity.
      • Usually weight loss is not permanent. Within a few years most who had initially succeeded in losing weight had returned to their original weight. Therefore, it is particularly important to develop and assess long-term treatments that aim at permanent weight loss.
      • Surgical treatment is an option in severely obese patients. On average, it reduces weight by more than 25% (e.g., from 125 to 90 kg) up to 5 years after surgery. After 10 years, a weight loss of approximately 16% remains, on average slightly over 20 kg. This has substantial health and quality of life benefits for the patient. The intervention, however, carries risks of complications.

      Environmental interventions need to be developed

      Although many environmental factors have been cited as contributing to obesity, there have been few controlled studies showing that changes in these factors will prevent weight gain. Environmental interventions attempt to modify the external surroundings with a goal of affecting behavioural changes, such as improvement in diet, increased physical activity, and or decreased sedentary behaviours. The aim of such interventions is to prevent weight gain, without exclusive reliance on an individual’s knowledge or motivation.

      Examples of environmental interventions include:

      • Providing safe walking or cycling routes in the context of a “walk/cycle to school” campaign;
      • Offering smaller portion sizes, at lower prices, in restaurants, cafeterias and/or vending machines;
      • Providing access to bicycle racks, lockers, showers, and other incentives to encourage cycling to work or school and physical activity during the workday;
      • Making stairways more accessible and attractive, through lighting, signals and open access, while discouraging the use of elevators.

      An integrated approach is recommended

      In 2005, the Heart and Stroke Foundation of Canada made an inventory of interventions related to obesity (HSF, 2005). They concluded that public health approach to disease prevention should not focus solely on risk behaviour education and behavioural skill development. It should also incorporate environmental and policy measures, plus an understanding of the barriers preventing behaviour change. Efforts to develop the next generation of preventive interventions must focus on building relationships with communities and develop interventions that derive from the communities’ assessments of their needs and priorities (HSF, 2005).

      Several authoritative bodies have published a range of opportunities for intervention related to obesity. A short review is presented in detailsOpportunities for interventions.


      28 April 2008
      Overweight
      Related EUphacts and EUphoci

      4 June 2009
      Overweight
      Relevant databases, organisations and projects

      Databases

      Organisations and projects

      Health-EU Portal, other non-communicable diseases

      Diet, Physical Activity and Health - EU Platform for Action

      EPHA European Public Health Alliance

      EASO The European Association for the Study of Obesity

      ECOG European Childhood Obesity Group

      EUROCISS European Cardiovascular Indicators Surveillance Set

      IASO The international Association for the Study of Obesity

      WHO Global Strategy on diet, physical activity and health

      IOTF International Obesity Task Force

      Bold CHILD Child Health Indicators of Life and Development

      PANACEA Physical Activity, Nutrition, Alcohol, Cessation of Smoking, Eating out of home And obesity

      EUDIP Establishment of Indicators Monitoring Diabetes

      EHRM European Health Risk Monitoring Project

      PorGrow Policy Options for Responding to the Growing Challenge from Obesity


      7 April 2008
      Overweight
      Figures, underlying data and maps

      Figures and Underlying Data

      TablePrevalence of overweight (BMI 25-29.9) and obesity (BMI 30+) in a number of countries

      TableEstimated increased risk for the obese of developing associated diseases

      ChartInternational cut off points for body mass index by sex for overweight and obesity, ages 2-18 years

      Maps

      MapPrevalence of obesity (BMI 30+), both sexes, for selected Isare health regions, in 1999


      Obesity

      Obesity 1999

      Remarks

      • Data were gathered by the correspondents of the ISARE project in each of the participating countries by contacts with the national statistical offices.
      • The ISARE project (health indicators in the regions of Europe) aims at gathering useful information on health indicators in the regions of the European Union.
      • The ISARE project firstly defined "health regions" within European Member States and then tested the feasibility of gathering data at those regional levels. The list of data to be collected was defined taking into account the ECHI list and information on the availability of these data at the regional level. The report of the ISARE-1 and ISARE-2 projects are available on the ISARE website. The ISARE-3 project continues the work of the ISARE-1 and -2 and includes data of new Member States (EU-25).
      • Some of the data are coming from Health examination surveys, others from Health interview surveys. For the latter, an underestimation is a common phenomenon. The age range usually includes the population of 15 and over, but sometimes it is 20 and over or 20-64. Because of these variations, a proper assesment of differences is difficult to make, especially between countries.

      7 February 2008
      Overweight

      Prevalence (%) of overweight (BMI 25-29.9) and obesity (BMI 30+) for men and women in a number of countries

      (source: IOTF, global prevalence database, 2007).

      Male

      Female

      age

      overweight

      obesity

      overweight

      obesity

      Austria (1999)

      25-64

      40.0

      10.0

      27.0

      14.0

      Belgium (1994-1997)

      35-59

      49.0

      14.0

      28.0

      13.0

      Cyprus (1999-2000)

      25-64

      46.0

      26.6

      34.3

      23.7

      Czech Republic (1997-1998)

      25+

      48.5

      24.7

      31.4

      26.2

      Germany (2002)

      25+

      52.9

      22.5

      35.6

      23.3

      Denmark (2003)

      ?

      -

      13.0

      -

      15.0

      Estonia (2004)b

      16-64

      32.0

      13.7

      28.4

      14.9

      France (2006)b

      15+

      35.6

      11.8

      23.3

      13.0

      Finland (2003)

      25-64

      48.0

      19.8

      33.0

      19.4

      Greece ATTICA (2001-2002)

      20-89

      53.0

      20.0

      31.0

      15 

      Hungary (1992-94)

      18+

      41.9

      21.0

      27.9

      21.2

      Italy (2003)

      18+

      42.1

      9.3

      25.8

      8.7

      Ireland (1997-99)

      18-64

      46.3

      20.1

      32.5

      15.9

      Luxembourg (?)

      16+

      45.6

      15.3

      30.7

      13.9

      Lithuania (2002)b

      20-64

      41.2

      16.4

      26.6

      15.8

      Latvia (1997)

      19-64

      41.0

      9.5

      33.0

      17.4

      Malta (2003)b

      18+

      46.5

      22.9

      34.3

      16.9

      Netherlands (1998-2002)

      20-59

      43.5

      10.4

      28.5

      10.1

      Poland (2002)

      18-94

      39.0

      10.9

      29.0

      12.4

      Portugal (2003)

      18-64

      49.1

      14.5

      31.9

      14.6

      Slovakia (1998)a

      15-64

      57.0

      22.0

      56.0

      28.0

      Slovenia (2001)b

      25-64

      50.0

      16.5

      30.9

      13.8

      Spain (1990-2000)

      25-60

      45.0

      13.4

      32.2

      15.8

      Sweden (1996-1997)

      16-84

      41.2

      10.0

      29.8

      11.9

      UK-England (2004)

      16+

      43.9

      22.7

      34.7

      23.8

      UK-Scotland (2003)

      16+

      43.0

      22.4

      33.8

      26.0

      UK-Wales (2003)b

      16+

      44.0

      17.0

      30.0

      18.0

      - : data unavailable

      UK: United Kingdom

      a urban, b self reported

      Remarks

      The numbers presented in the table are based on measured data unless otherwise stated, and collected by IOTF (global prevalence database).


      13 March 2007
      Overweight

      A summary of the strength of evidence for the relation between excess body weight and Cardiovascular Disease

      (adapted from AIHW, 2004)

      Cardiovascular disease

      • Good evidence of an association between overweight and obesity and CVD incidence among young to middle-aged men and women but not among older people.
      • Moderate evidence of an association between the duration of obesity and CVD mortality among adults, which may mediate the protective effect of overweight in older age.
      • Moderate evidence of an association between obesity and CVD mortality among adults.
      • Moderate evidence of an association between abdominal obesity and risk of CVD, particularly among older men.

      Coronary heart disease

      • Good evidence of an association between overweight and obesity and increased risk of CHD in adults.
      • Moderate evidence of an association between abdominal obesity and risk of CHD in older men and younger women.
      • Little evidence of an association between childhood and adolescent obesity and risk of CHD (particularly among girls), unless the children become obese adults.

      Heart failure

      • Moderate evidence of an association between overweight and obesity and risk of heart failure.

      Stroke

      • Moderate evidence of an association between overweight and obesity and increased risk of ischaemic stroke among adults
      • Moderate evidence of an association between abdominal adiposity and risk of stroke in men and women.

      13 March 2007
      Overweight

      Estimated increased risk for the obese of developing associated diseases, taken from international studies (adapted from NAO, 2001)

      Disease

      Relative Risk - women

      Relative Risk - men

      Type 2 Diabetes

      12.7

      5.2

      Hypertension

      4.2

      2.6

      Myocardial infarction

      3.2

      1.5

      Cancer of the colon

      2.7

      3.0

      Angina

      1.8

      1.8

      Gall bladder disease

      1.8

      1.8

      Ovarian Cancer

      1.7

      -

      Osteoarthritis

      1.4

      1.9

      Stroke

      1.3

      1.3

      Remarks

      The BMI range for the obese and non-obese groups used to estimate relative risk varies between studies, which limits the comparability of these data.


      13 March 2007
      Overweight

      Evidence of factors that might promote or protect against overweight or weight gain (Swinburn et al., 2004)

      Evidence

      Decrease Risk

      No Relationship

      Increase Risk

      Convincing

      • Regular physical activity
      • High intake of dietary non-starch polysaccharides (NSP)/fibre

      • Sedentary lifestyles
      • A high intake of energy dense foods

      Probable

      • Home and school environments that support healthy food choices for children
      • Breastfeeding

      • Heavy marketing of energy dense foods and fast food outlets
      • Adverse social and economic conditions (developed countries, especially for women)
      • High sugar drinks

      Possible

      • Low glycemic index foods

      • Protein content of the diet

      • Large portion sizes
      • high proportion if food prepared outside the home (western countries)
      • 'Rigid restraint/periodic disinhibition' eating patterns

      Insufficient

      • Increased eating frequency

      • Alcohol


      19 March 2007
      Overweight

      International cut off points for body mass index by sex for ages 2-18 years (data from Brazil, Britain, Hong Kong, Netherlands, Singapore, and United States) (source: Cole et al., 2000)

      Overweight - Figure 1

      Remarks


      13 March 2007
      Overweight
      Limitations of BMI as a measure of overweight and obesity

      BMI is an appropriate measure in spite of limitations

      BMI as a measure of population prevalence of overweight and obesity has certain limitations. Although generally related to body fat, it does not measure fat itself. BMI does not take into account skeletal size, amount of body water or muscle mass and it is not gender specific. Nevertheless, on a population level BMI is considered to be the most appropriate measure. It is easily calculated on the basis of standard measures that generally show little interobserver variation. Evaluation of BMI is inexpensive, it requires minimal training, and results are immediately available.

      Self reported data tend to underestimate overweight

      BMI can be monitored by means of questionnaires (self reported) or actual measurements of height and weight. Since people with obesity tend to underreport their bodyweight, self reported data tend to underestimate the scale of the overweight problem. Furthermore, errors in self reported height and weight may vary with age and overweight status (Kuczmarski et al., 2001).

      Obesity in children differs from obesity in adults

      Obesity in children is different from obesity in adults in some important respects. The main difference is that children and adolescents are growing. So for example, during puberty, a child’s weight will double and its height will increase by 20%. Simple measures of obesity such as the body mass index (BMI) cannot be used directly because it underestimates the degree of overweight in short children and overestimates overweight in tall children (Asp et al., 2002). The IOTF’s international standard for analysing childhood overweight and obesity data has now been widely adopted (IOTF, 2005b; Cole et al., 2000). It provides growth curves which relate cut-off points for different age groups to the adult categories for overweight and obesity (BMI 25-29.9 and BMI≥30 respectively; see ChartInternational cut off points for BMI).

      Ethnic differences in percentage of fat and fat distribution

      Percentage of body fat and fat distribution vary between different population groups. Apart from age and sex, ethnicity and physical activity level affect the percentage of body fat. For example, endurance runners have less body fat than swimmers. People living near the North Pole generally have more body fat than people living in more moderate temperature zones. Ethnic differences in fat proportion and corresponding risk levels might also stem from differences in relative leg lengths and/or in frame size (Deurenberg et al., 2002).

      Debate on different BMI cut-off points for different ethnic groups

      Due to differences across populations, there has been a debate on whether different BMI cut-off points for different ethnic groups should be developed. For example, a BMI of 27.5 in an Asian person may be associated with comparable morbidities to those seen in a Caucasian person with a BMI of 30. However, available data indicate amplified risks for Asians below conventional overweight or obesity markers. Therefore, an action point of BMI>23 was proposed by a WHO expert group, which nevertheless agreed that existing international classifications should be retained. The consultation identified potential public health action points (23.0, 27.5, 32.5, and 37.5 kg/m2) along the continuum of BMI, and proposed methods by which countries could make decisions about the definitions of increased risk for their population (WHO Expert Consultation, 2004).


      13 March 2007
      Overweight
      Papers on childhood overweight

      Two recent papers on childhood overweight

      Recently, two papers on overweight and obesity prevalence in European children have been published, involving at least 10 countries (Lobstein & Frelut, 2003; Lissau et al., 2004).

      Lobstein & Frelut: highest levels of childhood overweight in southern countries

      According to Lobstein & Frelut (data presented on the
      IOTF website), southern European countries report the highest levels of childhood overweight, including obesity. Spain, Portugal and Italy report levels exceeding 30% among children aged 7-11. England, Ireland, Cyprus, Sweden and Greece report levels above 20%, while France, Switzerland, Poland, the Czech Republic, Hungary, Germany, Denmark and the Netherlands report overweight levels of 10-20% among this age group. For teenagers (aged 13-17) seven EU-countries indicate overweight (including obesity) levels above 20%, with Crete (Greece) peaking at 35%. Rates of increase vary, with England and Poland showing the steepest increases.

      Lissau et al.: no clear pattern of childhood overweight in European countries

      Lissau et al. found a more equal distribution of overweight in European children aged 13 and 15 years. They conclude that overweight was significantly higher among 13 year olds of both sexes in Finland, Ireland, and Greece, and in Portuguese girls. Among 15 year olds, the prevalence of overweight was higher in Greek boys and in Danish and Portuguese girls. On the contrary, in Lithuania, there was a relatively low prevalence of overweight in both 13 and 15 year olds in both sexes.

      Differences in data collection methods

      It must be noted that the two papers used different data collection methods. The one by Lobstein & Frelut is based on a country by country collection of measured data, whereas the Lissau paper is based on The Health Behaviour in School-aged Children study (HBSC) which uses self-reported data. In general, measured data is preferred over self reported data, but the HBSC survey data have the advantage that all data are obtained in the same way and country trends can be compared. Representativeness of samples and periods of data collection also differ (Lissau, 2004).


      13 March 2007
      Overweight
      Opportunities for interventions

      Intervention strategies often targeted at childhood obesity

      There are several authoritative bodies that have published a range of opportunities for intervention. Some of them are very general and some are more specific. Often, intervention strategies are directed towards children. Lifestyle factors, including diet, eating habits, levels of physical activity as well as inactivity, are often adopted during the early years of life they argue, so prevention should take place in this age group.

      The British Medical Association published a report on childhood obesity that addresses various ways to tackle the problem of childhood obesity (BMA, 2005). The report concludes: "The BMA agrees with the International Obesity TaskForce that in order to halt the obesity epidemic,


      "...interventions at the family or school level will need to be matched by changes in the social and cultural context so that the benefits can be sustained and enhanced. Such prevention strategies will require a coordinated effort between the medical community, health administrators, teachers, parents, food producers and processors, retailers and caterers, advertisers and the media, recreation and sport planners, urban architects, city planners, politicians and legislators."

      "Environments that encourage healthy eating and active living are vitally important. The focus of such strategies should be to make it easier for the public to make healthy choices. Such strategies require funding for implementation, but should ultimately lead to a reduction in the costs to the NHS from obesity related ill health."


      EU Platform for Action on Diet and Physical Activity

      In March 2005, the European Commission launched the EU Platform for Action on Diet and Physical Activity. The platform commits all its stakeholders to fight obesity in the EU. The Commission is also exploring the scope for an EU wide code of conduct to rein back the marketing of unhealthy food to children by European advertisers. It stresses that the fight against obesity needs to be considered in the range of EU policies, such as agriculture, education and transport, that can have an impact on the epidemic. These actions will form the basis of an overall EU strategy on diet and physical activity to be published later this year.

      WHO Global strategy on diet, physical activity and health

      The WHO Global strategy on diet, physical activity and health provides Member States with a variety of global policy options to address the problem of unhealthy diet and physical inactivity. It states that effective weight management for individuals and groups at risk of developing obesity involves a range of long-term strategies. These include prevention, weight maintenance, management of co-morbidities and weight loss. They should be part of an integrated, multi-sectoral, population-based approach, which includes environmental support for healthy diets and regular physical activity.

      Key elements include:

      • Creating supportive population-based environments through public policies that
        • promote the availability and accessibility of healthy food and
        • provide opportunities for physical activity.
      • Promoting healthy behaviour to encourage and enable individuals to lose weight by
        • moving from saturated animal-based fats to unsaturated vegetable-oil based fats,
        • eating more fruit and vegetables, as well as nuts and whole grains,
        • engaging in daily moderate physical activity for at least 30 minutes.
      • Cutting the amount of fatty, sugary foods in the diet,
      • Develop a clinical response to the existing burden of obesity and associated conditions through
        • clinical programmes and
        • staff training to ensure effective support for those affected to lose weight or avoid further weight gain.

      19 March 2007
      Overweight
      Authors, editors and reviewers Overweight EUphact

      Author: Wilk EA van der (RIVM, Bilthoven, the Netherlands)

      Editor: Kramers PGN (RIVM, Bilthoven, the Netherlands)

      Reviewers: Oyen H van (IPH, Brussels, Belgium), Rigby N (IOTF, London, UK)


      Literature and data sources

      Literature and data sources

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      Rahkonen O, Lundberg O, Lahelma E, Huuhka M Body mass and social class: A comparison of Finland and Sweden in the 1990s  J Public Health Policy 1998; 19: 88-105.
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      Seidell JC. Obesity in Europe: scaling an epidemic.  Int J Obes 1995; 19 (suppl. 3): S1-S4.
      Stam-Moraga MC, Kolanowski J, Dramaix M, De Backer G, Kornitzer MD Sociodemographic and nutritional determinants of obesity in Belgium.  Int J Obes Relat, 1999; 23: S1-9.
      Swinburn BA, Caterson I, Seidell JC, James WPT. Diet, Nutrition and the Prevention of Excess Weight Gain and Obesity.  Public Health Nutrition, 2004; 7(1A): 123–146.
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      Data sources

      IOTF. IOTF global prevalence database