- One in six children is overweight or obese.
- One in five adults is obese.
- Overweight and obesity increase the risk for type 2 diabetes and a number of other chronic diseases.
- Overweight and obesity have increased in the Norwegian population in recent decades but there are signs that this trend has levelled off among children.
About overweight and obesity
Body mass index (BMI) is a good indicator of overweight and obesity in a population. It can be misleading on an individual level because people with a lot of muscle or who have shrunk in height may have a too high BMI.
The positioning of body fat plays a role and abdominal obesity seems to have a stronger association with type 2 diabetes and cardiovascular disease than general obesity.
Status of overweight and obesity
One in six children is overweight or obese
Results of the various health studies among children in Norway show that
- Between 15 and 20 per cent of children are overweight / obese (Dvergsnes 2009, Juliusson 2007, Kolle 2009, Norwegian Child Growth Study)
- Eight per cent of third-graders have abdominal obesity Norwegian Child Growth Study)
One in four adolescents is overweight
Results from the Health Study in Nord-Trøndelag (HUNT) in 2006 to 2008 (Krokstad, 2011) show that
- 22 per cent of boys and 20 per cent of girls in high school are overweight
- 27 per cent of boys and 25 per cent of girls in further education are overweight
One in five adults is obese
Health studies in Norway (Figure 1) since 2000 which measured height and weight show that
- approximately 20 per cent of men and 17 per cent of women aged 40-45 years are obese (BMI ≥ 30 kg / m2).
- overall, there are more men than women who are obese, but the percentage with grade 2 or grade 3 obesity (BMI ≥ 35 kg / m2) is higher among women than men (5 per cent among women and 3.5 per cent among men)
- if this percentage is applied to the total population in the age group 40-49 years, it can be estimated that 32,500 people have BMI ≥ 35 kg / m2 (grade 2 or grade 3 obesity).
Data from the HUNT study indicate that among adults with BMI ≥ 35 kg / m2 almost half (40-50 per cent) are morbidly obese (defined as a follow-on disease or BMI ≥ 40 kg / m2) (personal communication, Kristian Midthjell).
| Figure 1: Percentage (%) of men and women (kvinner) 40-45 years with obesity in seven counties. Green = grade 1 obesity (BMI 30 - 34.9), and orange = percentage of grade 2 or 3 obesity (BMI ≥ 35). Sources: Health Studies in Oslo (2000/01), Hedmark (2000/01), Oppland (2001), Troms (2001/3), Finnmark (2002/3), Tromsø (2007/8, Jacobsen, unpublished data) and North Trøndelag (2008 Midthjell, unpublished data). |
Development over time
Figures from the Medical Birth Registry show that the average birth weight has increased, with a peak around the year 2000, but this has since declined and is now back to 1990 levels (see figure 2).
| Figure 2: Average birth weight (in grams) 1990-2012. Data source: Medical Birth Registry of Norway|
The percentage of overweight children appeared to greatly increase in Norway towards the beginning of the 2000s (Juliusson, 2007). However, over the last decade it seems that the percentage of school children with overweight and obesity has changed little, and results from the Norwegian Child Growth Study at the Norwegian Institute of Public Health show these results for the period 2008-2012:
- The percentage of third graders with overweight, including obesity, has remained stable, with an average of 16 per cent (see Figure 3).
- The percentage of third graders with abdominal obesity has changed little, with an average of eight per cent.
New national measurements taken as part of the Norwegian Child Growth Study in 2015 will provide more data about the development of overweight and abdominal obesity among Norwegian children.
Abdominal obesity is considered together with an increased risk of metabolic disease, also in children (Maffeis, 2008) and research suggests that the average waist circumference and abdominal obesity has increased to a greater extent than the average BMI over a longer period (McCarthy, 2005), also in Norway (Kolle, 2009).
|Figure 3: Percentage (%) boys and girls in the third grade (8-9 year-olds) who are overweight or obese (IOTF, International Obesity Task Force - Cole, 2000). Source: Norwegian Child Growth Study 2008, 2010 and 2012, NIPH.|
We do not have systematic national measurements that show the development of obesity among adolescents over time. Data from the Health Study in Nord-Trøndelag (HUNT) report a worrying development of obesity, including obesity among young people in the 13-18 year age group in the period 1968 to 2008.
By the end of the 1960s, only about five per cent of Norwegian middle-aged men were obese. After this, the average weight increased continuously until the millennium. The increase was particularly strong at the end of the 1990s. In women, the percentage with obesity decreased from 13 to 7 per cent in the period from the 1960s to the end of the 1970s but then the weight increased in the same way as for men (Meyer & Tverdal, 2005).
There have been few health studies among adults in recent years so it is therefore difficult to comment on weight development during this period. Based on data from the Tromsø Study it appears that the increase in the prevalence of obesity in men, but not in women, has been more moderate in the period 2001 to 2008 compared with the previous years (see figure 4).
| Figure 4: Percentage with obesity (BMI ≥ 30 kg / m2) in the Tromsø studies. Men and women (kvinner) aged 30-69 years. Age-adjusted figures. Source: Koster Jacobsen, unpublished data. |
Differences among people
Less obesity in urban areas
The prevalence of obesity in adults is lower in towns than in rural areas, especially among women.
Data from the Norwegian Child Growth Study show that the prevalence of obesity is 50 per cent higher among children in rural areas compared with children in towns. The percentage of abdominal obesity follows the same pattern (Biehl 2013). In addition, the prevalence of overweight (including obesity) is highest in the northern health region and lowest in the south east health region (Norwegian Child Growth Study).
Differences among the immigrant population
The prevalence of obesity is high among immigrants from Pakistan and Turkey, but low among immigrants from Vietnam. Women from Sri Lanka and Pakistan have most abdominal obesity and the highest incidence of diabetes (Jenum, 2012).
There are socioeconomic differences in the incidence of obesity and overweight. Previous Norwegian studies showed that the percentage of obesity was lower among 40-year-olds with a high level of education than among 40-year-olds with a lower education (Meyer & Tverdal, 2005). In Oslo, the adult population is heavier in the eastern than in western districts, especially women (Oslo Health Study 2000-2001).
Data from the Norwegian Child Growth Study show that there are also socioeconomic differences for overweight and obesity among children. Data analyses from the Norwegian Child Growth Study 2010 show that the percentage of overweight is 30 per cent higher among children of mothers with lower education than among children of mothers with a higher education. The percentage of abdominal obesity follows the same pattern (Biehl 2013).
North-south gradient of obesity among children in Europe
The Norwegian Child Growth Study at the Norwegian Institute of Public Health is a part of the WHO European Childhood Obesity Surveillance Initiative (Wijnhoven, 2013).
Results from different European countries show that there is a clear north-south gradient where countries in southern parts of Europe have a much larger percentage of children with overweight (including obesity) compared to children in Norway and other Nordic countries (see Table 1).
Table 1: Proportion of boys and girls with overweight (incl. obesity) by age and country. (1) Based on limit values set by IOTF. Source: (Wijnhoven, 2013)
Proportion with overweight (incl. obesity) 1
Proportion with overweight
(incl. obesity) 1
Difficult to compare countries
The increase in weight that we have seen among adults in Norway is part of an international trend. However, a new report shows a stabilisation of weight in the period 2003 to 2012 in the USA (Ogden, 2014).
It is difficult to accurately rank Norway internationally due to the different methods and quality of the studies used for comparison. However, it appears that the prevalence of obesity among adults is lower in Norway than in many other countries (OECD, 2012).
Inactivity and high energy intake increases the risk of overweight and obesity
At the population level, the changes in environmental conditions rather than the genetic changes may explain the major changes we have seen in weight in the Norwegian population in recent decades. We live in a society that encourages physical inactivity and offers a broad and tempting range of food.
These are two of the conditions that contribute to increased risk for overweight and obesity:
- It is well-documented that inactivity increases the risk of overweight and obesity, and that the risks are reduced by regular physical activity (NNR5, 2014).
- While foods with low energy density are often rich in fibre and water (such as vegetables and many types of fruit), foods with a high energy-density often contain a lot of fat and added sugar.
To maintain a stable weight, the intake of food and drink must be in balance with energy expenditure through physical activity. There are many personal factors that may affect the energy balance, including heredity. Therefore, some people have more trouble maintaining a healthy weight than others.
Breastfeeding reduces the risk of overweight and obesity in children and adolescents, while the relationship between breastfeeding and overweight and obesity in adults is less certain (NNR5).
Associations between psychological problems and obesity
Literature reviews of large population studies show an over-representation of psychological problems such as anxiety and depression in the group with obesity (de Wit, 2010). Longitudinal studies have shown that anxiety and depression influence the risk of subsequent obesity, and that obesity can lead to anxiety and depression (Berkowitz & Fabricatore, 2011).
Psychological problems may affect the appetite, will and self-control, which are all important factors in the development of obesity. Individuals with anxiety, depression and psychoses are more vulnerable to experiencing stress and helplessness when they face difficulties. This may lead to comfort eating, particularly of food that is rich in fat, sugar or salt.
Taking medicine can explain a part of the relationship between obesity and mental health problems. A common side effect of the medication for serious psychological disorders involves changes in the brain mechanisms that control appetite and metabolism, which in turn can lead to weight increases (Carlat, 2012; Ferno, 2011).
Health risks related to obesity
Obesity in adults increases the risk of a range of diseases and complaints (Norwegian Directorate of Health):
- type 2 diabetes
- cardiovascular diseases
- certain types of cancer (oesophageal, pancreatic, colon, rectal, breast (post-menopausal), uterine, renal)
- sleep apnea
- osteoarthritis of the hips and knees
- stigma, psychological distress and unhappiness
The risk of osteoporosis and fracture is lower among obese people than in thin people. Among the elderly we find the lowest mortality with a somewhat higher BMI than in younger people and among the eldest, low body weight is a major health challenge (Kvamme, 2011).
A number of other factors than weight and weight development will play a role in how health will develop in the Norwegian population in the future. A healthy diet and physical activity are preventive, while smoking constitutes an additional risk.
Despite the increase in weight among the population, the prevalence of cardiovascular diseases has decreased. One reason may be that we also have had positive trends with regards to blood lipids, a decrease in blood pressure and fewer smokers. Recent figures indicate that the decline in cardiovascular disease might turn among the youngest (Sulo, 2013). This may indicate that the positive trends among the other risk factors have tailed off so that the total risk has increased in this group.
Prevention on a population level
Making a difference to overweight and obesity at the population level requires both population-oriented and individual-oriented interventions from the public sector, the food industry, providers of food and drink, etc. Children and adolescents are particularly exposed and are influenced by family, childcare, school and their community.
Internationally, we see an increasing discussion about which public health interventions can and should be used to encourage weight loss in a society. Population-oriented interventions that are being discussed in Norway are more organized physical activity in schools and the community and limiting the availability of high-energy, nutrient-poor foods, such as sweet drinks. Interventions at the community level can reach more people and be more effective than just focusing on individual-oriented interventions to control weight.
- Berkowitz, R. I. and A. N. Fabricatore (2011). Obesity, psychiatric status, and psychiatric medications. Psychiatr Clin North Am 34(4): 747-764.
- Biehl, A., R. Hovengen, E. K. Groholt, J. Hjelmesaeth, B. H. Strand and H. E. Meyer (2013). Adiposity among children in Norway by urbanity and maternal education: a nationally representative study. BMC Public Health 13: 842.
- Carlat, D. (2012). Evidence-based somatic treatment of depression in adults. Psychiatr Clin North Am 35(1): 131-142.
- Cole, T. J., M. C. Bellizzi, K. M. Flegal and W. H. Dietz (2000). Establishing a standard definition for child overweight and obesity worldwide: international survey. Bmj 320(7244): 1240-1243.
- de Wit, L., F. Luppino, A. van Straten, B. Penninx, F. Zitman and P. Cuijpers (2010). Depression and obesity: a meta-analysis of community-based studies. Psychiatry Res 178(2): 230-235.
- Dvergsnes, K. and G. Skeie (2009). Utviklingen i kroppsmasseindeks hos fireåringer i Tromsø 1980 – 2005. Tidsskr Nor Laegeforen 129(1): 13-16.
- Ferno, J., S. Skrede, A. O. Vik-Mo, G. Jassim, S. Le Hellard and V. M. Steen (2011). Lipogenic effects of psychotropic drugs: focus on the SREBP system. Front Biosci (Landmark Ed) 16: 49-60.
- Jenum, A. K., L. M. Diep, G. Holmboe-Ottesen, I. M. Holme, B. N. Kumar and K. I. Birkeland (2012). Diabetes susceptibility in ethnic minority groups from Turkey, Vietnam, Sri Lanka and Pakistan compared with Norwegians - the association with adiposity is strongest for ethnic minority women. BMC Public Health 12: 150. Pubmed.
- Juliusson, P. B., M. Roelants, G. E. Eide, R. Hauspie, P. E. Waaler and R. Bjerknes (2007). Overweight and obesity in Norwegian children: secular trends in weight-for-height and skinfolds. Acta Paediatr 96(9): 1333-1337.
- Kolle, E., J. Steene-Johannessen, I. Holme, L. B. Andersen and S. A. Anderssen (2009). Secular trends in adiposity in Norwegian 9-year-olds from 1999-2000 to 2005. BMC Public Health 9: 389.
- Krokstad, S. and M. S. Knudtsen Folkehelse i endring: helseundersøkelsen Nord-Trøndelag : HUNT 1 (1984-86) - HUNT 2 (1995-97) - HUNT 3 (2006-08). Levanger, HUNT forskningssenter. (2011).
- Kvamme, J. M., J. Holmen, T. Wilsgaard, J. Florholmen, K. Midthjell and B. K. Jacobsen (2012). Body mass index and mortality in elderly men and women: the Tromso and HUNT studies. J Epidemiol Community Health 66(7): 611-617. Pubmed.
- Maffeis, C., C. Banzato and G. Talamini (2008). Waist-to-height ratio, a useful index to identify high metabolic risk in overweight children. J Pediatr 152(2): 207-213.
- McCarthy, H. D., K. V. Jarrett, P. M. Emmett and I. Rogers (2005). Trends in waist circumferences in young British children: a comparative study. Int J Obes (Lond) 29(2): 157-162.
- Meyer, H. E. and A. Tverdal (2005). Development of body weight in the Norwegian population. Prostaglandines, Leukotrienes and Essential Fatty Acids 73(1): 3-7.
NNR5. Nordic nutrition recommendations 2012: integrating nutrition and physical activity. [København], Nordisk Ministerråd: 627 s. : fig. (2014).
- Norwegian Directorate of Health. National guidelines for prevention and treatment of obesity among adults (2011).
- Norwegian Institute of Public Health. Child Growth Study in Norway (Barnevekststudien).
- OECD. Health at a Glance: Europe 2012. Overweight and obesity among adults. Hentet: juni 2014. OECD iLibrary
- Ogden, C. L., M. D. Carroll, B. K. Kit and K. M. Flegal (2014). Prevalence of childhood and adult obesity in the United States, 2011-2012. JAMA 311(8): 806-814.
- Sulo, G., J. Igland, O. Nygard, S. E. Vollset, M. Ebbing and G. S. Tell (2013). Favourable trends in incidence of AMI in Norway during 2001-2009 do not include younger adults: a CVDNOR project. Eur J Prev Cardiol. Pubmed.
- Wijnhoven, T. M., J. M. van Raaij, A. Spinelli, A. I. Rito, R. Hovengen, M. Kunesova, G. Starc, H. Rutter, A. Sjoberg, A. Petrauskiene, U. O'Dwyer, S. Petrova, V. Farrugia Sant'angelo, M. Wauters, A. Yngve, I. M. Rubana and J. Breda (2013). WHO European Childhood Obesity Surveillance Initiative 2008: weight, height and body mass index in 6-9-year-old children. Pediatr Obes 8(2): 79-97.