Childhood obesity
- an important challenge

Obesity defined as BMI over 30 is a complex and chronic disease. A child or young person living with obesity has an increased risk of developing comorbidities both during childhood and in the long term. Even children or young people who are overweight and have a BMI between 25 and 30 have an increased risk of developing diseases in the future (1). According to the NHS Constitution, the Children Act 1989, and the Health and Social Care Act 2012, all children in the UK have the right to receive treatment for the condition of obesity based on clinical need.

Prevalence and risks

Prevalence
There are approximately 160 million children and adolescents with obesity in the world today (aged 5-19). This number is expected to increase to roughly 250 million by the year 2030. Obesity among children is common in Sweden today. The documentation is incomplete, but existing data indicate that between 4-10% of children in Sweden suffer from obesity (2,3).

Obesity in childhood and premature death
Childhood obesity leads to shortened life expectancy (4,5,6,7). Obesity leads to shortened lifespan at all ages, but the effect is more obvious if obesity develops at a young age (8). Research shows that basically all organ systems in the body are affected in childhood obesity (9).

Figure 1. Diseases and conditions caused or aggravated by obesity during childhood and adolescence. Obesity in children is a chronic disease where almost every organ system in the body can be affected (9).

Disturbed glucose homeostasis
Children with obesity already develop insulin resistance before school age. Early stages of type 2 diabetes are common among obese children in Sweden, significantly more common than in other countries such as Germany (10). Type 2 diabetes is also occurring to an increasing degree, but many are first affected as young adults. In Sweden, the risk of developing type 2 diabetes as a young adult is more than 20 times greater if you suffer from obesity as a child (11). Type 2 diabetes affecting young people is a serious disease with a poor prognosis. It is a significantly more dangerous disease to get as a young adult than in middle age. Compared to type 1 diabetes, type 2 diabetes has an alarmingly high mortality and rapid development of sequelae such as kidney and eye complications (12,13). This also applies in Sweden and it is not due to social factors. Children with type 2 diabetes have better sugar control than children with type 1 diabetes, but despite this, the development of secondary diseases is faster (14).

Blood lipids, vascular effects and blood pressure
Childhood obesity is linked to an increased risk of developing vascular involvement. Several factors influence this, including the fact that obesity leads to increased inflammation and elevated values of LDL cholesterol and triglycerides. Children with obesity therefore have increased intima-media thickness in the carotid vessels and also a disturbed vessel functionality (15). Children with obesity have an increased risk of hypertension (16). This is also common in Sweden (17) which is documented in the national quality register BORIS. High blood pressure also occurs at the age of 5-10 years. Children and young people with obesity relatively often have disturbed diurnal variation in their blood pressure (18,19) which is considered predisposing to heart muscle damage. Childhood obesity leads to an increased risk of heart attack as an adult (20).

Fatty liver, asthma and joint problems
Fatty liver is relatively common among children with obesity and this is associated with later risk of liver fibrosis (21). Obesity leads to reduced lung volume, but obesity also leads to an increased risk of asthma among children (22), likely linked to the increased general inflammatory activity.

Cognitive impairments

Childhood obesity leads to a greatly increased risk of school problems (23). To what extent this is due to discriminatory behavior from the environment and how much is due to a direct effect of obesity on cognition is unclear, but it is independent of socioeconomic status. Children with obesity have morphological changes in the central nervous system (24). Animal studies show that obesity and excess consumption of fatty foods lead to cognitive disorders (26). Weight reduction among adults leads to improved memory (26,27) and improved sugar regulation. Improved sugar regulation among type 2 diabetics quickly leads to improved cognitive functions (28). These studies indicate that the connection between cognition and obesity is causal and reversible, ie that obesity leads to cognitive disorders and that treatment.

Treatment of childhood obesity

Effect of treatment on weight development

Childhood obesity is mainly treated with behavioral support that should lead to lifestyle changes, which in turn should lead to weight loss. The more frequent support is offered, the better results can be achieved (6,29). In the annual report for the national quality register for childhood obesity treatment, BORIS, the results achieved in Sweden are described. There are several scientific articles that also confirm the effect of treatment. Treatment should be started early, younger children have a significantly better effect than older ones and the effect is also better if you treat before the degree of obesity becomes too high (30,31,32). Bariatric surgery is also used for young people with relatively good results (33). The effect of obesity and the diabetes drug liraglutide has also recently been evaluated in young people with relatively good results (34). The application for approval for the treatment of adolescent obesity has been submitted in both the US and the EU.

Effect of treatment on school performance

There is a direct relationship between weight development and school performance that is not related to

socio-economic standard. The children who reduce their degree of obesity perform significantly better in school.

46% of obese children who do not lose weight do not graduate from high school with passing grades, but this number drops to 33% for those who are effectively treated and lose 0.25 BMI SDS units in weight (23).

Effect of treatment on future morbidity
A sharp weight loss drastically reduces almost all risk markers for future morbidity (33). Anyone who was obese as a child but enters adulthood without obesity has the same risk of future cardiovascular morbidity as someone who was not obese as a child. Metabolic syndrome during adolescence that disappears before adulthood leads to normalized blood vessels and normalized risk of type 2 diabetes (35). Even a moderate weight loss leads to a reduced risk of early onset of type 2 diabetes (11). A relatively strong weight loss is required to normalize blood pressure, which is not often achieved with conventional lifestyle treatment (17).

Behavioral support conventional childhood obesity treatment is time-consuming and expensive
As mentioned above, childhood obesity treatment is time consuming. If it is not allowed to be so, the efficiency drops, which it has done in Sweden in recent years (36) and then care tends to become pointless for those who need it most. In a larger literature review, the United States Preventive Services Task Force has calculated that families need 26 hours of contact with healthcare for a treatment with reasonable safety to lead to a clinically significant reduction in obesity (29). Such treatment is not always possible. Many families cannot be away from work for that much time and the travel time to the treating unit can also make it impossible to carry out such intensive treatment. In addition, the healthcare system does not always have the resources to allocate to the extent required, despite the long-term socio-economic gain of an effective treatment of childhood obesity being indisputable and despite the great suffering that the disease obesity entails for many children and young people. New innovative treatment supports are under development which, together with mediction and surgery, will create opportunities to help more children with obesity to a healthier life.

Societal cost

The cost increase for a child with obesity, compared to a child of normal weight, has been calculated in Sweden at 780,000 SEK per individual up to the age of 65 (37,38). This means that it is a long-term financial gain for society if treatment is started in time, even if only a small part of the children would get a good effect from the treatment. The cognitive and psychosocial effects of obesity on societal costs are also large. Half of the young people who do not graduate from high school with passing grades end up in exclusion, and the cost of exclusion is approximately SEK 20 million per individual (39). Based on the improved school results (see above), the social gain can be calculated at SEK 1.4 million per effectively treated child with obesity in reduced costs for exclusion.