Childhood obesity, a scourge to fight

January 10 is the National Childhood Obesity Screening Day. Obesity is defined as an abnormal buildup of body fat in an individual that can lead to serious health problems. The number of children suffering from it increases year after year. The World Health Organization (WHO) has made it one of the major public health challenges of the 21st century.

Where are we today?
The latest WHO 2021 report on childhood obesity covers four successive studies of children aged 6 to 9 around the world. Thirty-eight countries participated, making it easier to identify the influencing factors. The results presented in this report show an alarming trend in childhood overweight and obesity worldwide.
Based on all the data collected, the WHO declares globally a proportion of obesity of 13% in boys and 9% in girls among 7-9 year old children. The French obesity league also surveyed in 2020 specifically the French population that is broader in terms of age. Researchers estimate that 18% of children aged of 2 to 7 and 6% of children aged of 8 to 17 are obese, which would appear consistent with WHO report.
There is a geographic disparity in the prevalence of obesity. For example, Central Asian countries like Turkmenistan have fewer obese children, while countries like Italy and Spain have the highest rates in the WHO report. Likewise, this difference also exists within the same country between cities and countryside, the former being more affected.

A pathology under the influence
This leads us to discuss about the factors that facilitate the onset and deepening of obesity in children. One of the first influencing factors is dietary imbalance. Junk food is increasingly present in developed, but also in emerging countries. It is a real brake on the health and physical well-being of children and adolescents. Eating disorders, especially bulimia and hyperphagia, can also lead to the development of obesity if care is not adapted and the root cause not considered and treated.

The current sedentary and screen-oriented lifestyle often allows excess weight to settle in over a prolonged period of time. Physical activity, from the age of 2, can even predict the future onset of obesity: children who spend less time actively playing at the age of 2 years will hasten a phenomenon called rebound of adiposity (designates the increase in the body mass index -BMI- of the child around 6 years after having reached its lowest point), presaging a future obesity.

Figure 1 : Child’s body mass index-for-age percentiles

Finally, the geographic difference in obesity prevalence is partly explained by these two elements:, there is less direct access to unhealthy food in less developed countries and in rural areas, just as physical activity is more important due to obligation and / or to greater access to a healthy outdoor area.
These two factors have also raised concerns among health authorities of a drastic increase in obesity prevalence since the start of the Covid-19 pandemic. Among the closure of schools and the lockdowns, the conditions have been met to promote an aggravation of these elements.
The educational and social environment in which the child evolves can also be predisposing to obesity. Children with obese parents will be more likely to develop obesity. The parents' socio-professional category also seems to have an impact. Regardless of the child's age, they are more at risk of developing obesity if they grow up in a family of the so-called popular or inactive category.

Programmed obesity
It is now known that genetic factors can predispose to a risk of developing obesity in both adults and children. It has recently been identified that these genetic factors are different depending on age. Researchers evaluated the impact on BMI of two different panels of genes at risk of obesity and they were able to show that one of the panels is correlated with BMI in children up to the age of about 16 years old, after which the risk becomes associated with the second panel of genes. This opens up a field of work for understanding mechanisms of predisposition for better care and prevention of obesity in different age groups.
In the same way that certain genes confer a predisposition, there are factors known as programmers which act from the conception of the child, in the womb of its mother. Too much weight gain during pregnancy, poorly balanced gestational diabetes, smoking, insufficient intake of omega-3 or even exposure to pollutants are all factors contributing to obesity in children.

What are the main risks for these children?
Unfortunately, childhood obesity has been shown to increase the risk of premature death. This increase is explained in particular by the increased risk of developing cardiovascular diseases such as high blood pressure, which is normally rare in young people, or by an increased risk of severe diabetes with severe insulin resistance. Obesity also leads to a high number of depressions as well as social isolation which can be truly destructive for children who seek to build their identity and find their place in society. The most tragic outcomes, sometimes considered by these children, being suicide.

Figure 2: Childhood mortality with or without obesity.

The tools to fight it
Prevention and awareness are the first tools in fighting childhood obesity. It is essential that all children have access to them. Play-based training in schools and adapted brochures are part of these strategies. The ban on vending machines in French schools since 2005 is also a preventive act.
To screen for childhood obesity, the fundamental point is the systematic monitoring of the weight curve and BMI of each child. If an abnormality is detected, then multidisciplinary follow-up should be instituted. It is important to explore diet, physical activity, psycho-social factors, sleep pattern, etc. RéPPOP networks (Pediatric Obesity Prevention and Support Networks) are gradually developing throughout France and are providing support which also allows parents to be more involved in helping their children. The follow-up in these networks is done over two years and should help to lower obesity levels and put the child and his family back on the right track.
Two words should be remembered after this article: prevent and detect. These are the two actions that will gradually limit the scourge that is childhood obesity. It is essential to allow each child to live in good health and to grow serenely. Care is more and more appropriate, but it is not yet sufficiently accessible everywhere. The development of these networks is therefore decisive in the years to come for equal access to care for all children and a reversal of the trend of development of obesity in children.

Sources
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