By: Dr. Fidelis Nwachukwu, Lecturer of Microbiology
WHO, the World Health Organization, defines obesity as “abnormal or excessive fat accumulation that present a risk to health”. It is difficult to obtain one simple index for the measurements of overweight and obesity in children and adolescents because their bodies undergo a number of physiological changes as they grow. Therefore, for children, age needs to be considered when defining overweight and obesity.
Hence, for children under 5 years of age: overweight is weight-for-height greater than 2 standard deviations above the WHO Child Growth Standards median; and obesity is weight-for-height greater than 3 standard deviation above the WHO Child Growth Standards median.
Whereas, for children aged between 5-19 years: overweight is BMI–for-age greater than 1 standard deviation above the WHO Growth Reference median; and obesity is greater than 2 standard deviation above the WHO Growth Reference median.
Consensus committees have also recommended that children and adolescents be considered obese if the BMI exceeds 30kg/m2 at any age.
Pediatric obesity is currently one of the most important global public health challenges. WHO describes pediatric obesity as “one of the most serious public health challenges of the 21st century”. Today, about one in three American kids and teens is overweight or obese. The prevalence of obesity in children more than tripled from 1971 to 2011.
Globally, in 2016, over 41 million children under the age of 5 were overweight or obese and over 340 million children and adolescents aged 5-19 were either overweight or obese (WHO, 2016). Once considered a high-income country problem, overweight and obesity are now on the rise in low- and middle-income countries, particularly in urban settings.
Overweight and obesity are linked to more deaths worldwide than underweight. Globally, there are more people who are obese than underweight – this occurs in every region except in a few parts of sub-Saharan Africa and Asia.
CAUSES: The fundamental cause of obesity and overweight is an energy imbalance between calories consumed and calories expended. Changes in dietary and physical activity patterns are largely responsible for this imbalance. This includes increase in snacks and portion size of meals with concomitant decrease in physical activity, social policies such as easy access to vending machines and fast food restaurants, advertising of unhealthy foods such as candy, increased use of technology, and socioeconomic status.
In addition genetic syndromes associated with childhood obesity play a role. For example, Prader-Willi syndrome, pseudohypoparathyroidism, Laurence-Moon-Beidl (Bardet-Beidl) syndrome, Cohen syndrome, Down syndrome, Turner syndrome; hormonal disorders (growth hormone deficiency, growth hormone resistance), hypothyroidism, leptin deficiency or resistance to leptin action, glucocorticoid excess (Cushing’s syndrome), precocious puberty, polycystic ovarian syndrome (PCOS) all contribute to childhood obesity and overweight.
There are also medications that may cause weight gain in children and adolescents. Such medications include the corticosteroids, oral hypoglycemics – sulphonylureas and thiazolidinediones, monoamine oxidase inhibitors (MAOIs), such as phenelzine, oral contraceptives, insulin (in excessive doses), antipsychotics, such as risperidone, and clozapine.
COMPLICATIONS: Childhood obesity is associated with a higher chance of obesity, premature death, and disability in adulthood. In addition to increased future risks, obese children experience breathing difficulties, psychosocial dysfunction, and increased risk of fractures, hypertension, and early markers of cardiovascular disease, insulin resistance, and psychological effects.
PREVENTION: Childhood overweight and obesity is preventable. Prevention is a collective responsibility of individuals, communities, schools, physicians, food industries and the government.
Management at the individual level involves limiting energy intake from total fats and sugars, increasing the consumption of fruits and vegetables, legumes, whole grains and nuts, and engaging in regular physical activity (60 minutes a day for children). Food industries can play a role by reducing the fat, sugar, and salt content of processed foods, while the government can implement policies that make regular physical activity and healthier dietary choices available, affordable, and easily accessible to everyone, particularly to the poorest of individuals.
In conclusion, despite the continuous battle with infectious diseases and undernutrition in middle- and low-income countries, the increase in overweight and obesity among children is a cause for worry and appropriate measures need to be taken to prevent its rise in prevalence. Management of childhood obesity is multi-disciplinary, requiring the efforts of nurse educators, nutritionists, exercise physiologists, counsellors and doctors. Support from family is also key as any intervention without it is likely to fail. Management strategies include lifestyle modification, psychotherapy, and/or surgical intervention (bariatric surgical procedures) when indicated in the most severe cases that are resistant to other forms of therapy.