There has been a steady rise in the prevalence of overweight and obese children in all regions of the world. In very extreme cases, researchers are reporting prevalence rates for overweight/obesity in the range of 10 – 40% in developed nations. In actual numbers, 50 million girls and 74 million boys were obese in 2016. The global burden of diseases project found that the prevalence of overweight/obesity among adolescents nearly doubled from 1990 to 2016, with a current prevalence of 18%. It is more disturbing that this rise in the prevalence of overweight and obesity is faster in low and middle income countries (LMIC) compared to the developed countries. There are studies in Africa which are already reporting prevalence of overweight/obesity higher than this global average.
Rising prevalence of Adolescent Obesity in Nigeria
In the past few decades, Nigerian studies on the nutritional status of children hardly reported childhood obesity, but this is changing in recent times. Some Nigerian studies are reporting prevalence of childhood or adolescent overweight/obesity close to the global average. It is more worrisome that studies are showing an alarming rise in the prevalence of adolescent obesity. For example, a study we carried out in a Nigerian state in 2011 reported a prevalence rate less than 1% for adolescent obesity, whereas another study we did, in the same state and among a similar population of adolescents, reported a prevalence greater than 10% eight years later. In another graphic example, the prevalence of childhood overweight/obesity reported by UNICEF for Nigeria increased from 2% to 8% within 2 years (2017 to 2019).
Reason for the rising prevalence of Adolescent Obesity in Nigeria
The increasing prevalence of overweight and obesity have been attributed to nutrition transition. According to Popkin, nutrition transition depicts the change from the traditional food patterns rich in fruits, vegetables and fibre, to what has been called the western food pattern. This western food pattern describes food rich in sugar, refined foods, saturated fats with little or low fibre. Nutrition transition also involves the reduction in energy expenditure and the more sedentary lifestyles brought about by technological improvements. Nigeria is experiencing nutrition transition, with rapid urbanization and associated adoption of western diets and reducing energy expenditure among children and adolescents. The increasing pattern of westernized diets and reduced physical activity including excessive consumption of media has been reported among Nigerian Children.
Implication of the rising prevalence of Adolescent Obesity in Nigeria
The major challenge with the increasing prevalence of overweight/obesity among adolescents is the morbidity and mortality that has been associated with these nutritional states. Overweight/obesity among children and adolescents has been associated with an increased risk for cardiovascular and metabolic diseases, which have been termed cardio-metabolic diseases. Increasing number of studies are reporting significant relationships between rising body mass index and high blood pressure, glucose intolerance and metabolic risks.
Findings from a recent Nigerian Study
We carried out a study recently among Nigerian adolescents living in the South-western part of the country, and the study aimed to estimate the prevalence of obesity and its relationship with the cardiometabolic health of the adolescents.
The overall prevalence of overweight/obesity that we found among the adolescents was 10.2%. This prevalence is higher than the country specific estimate, the regional estimate for West Africa and the global estimate by the joint child malnutrition estimates by WHO and UNICEF. We also found the prevalence of systolic and diastolic pre-hypertension to be 10.9% and 11.5% respectively, while the prevalence for systolic and diastolic hypertension were 14.4 and 8.6% respectively. Overall, nearly a third of the adolescents had either elevated systolic and/or diastolic blood pressure. Similar findings, but with higher prevalence of pre-hypertension have been reported by another author in Nigeria, also working among Nigerian adolescents. After controlling for all independent variables using binary logistic regression analysis, those that were overweight/obese were six times more likely to have raised blood pressure than others.
The Government at all levels in Nigeria, Non-governmental organizations and other stakeholders in Adolescent health need to show more interest in the issue of adolescent obesity and its attendant health risks.
Adeleye is a Lecturer at the Obafemi Awolowo University, Ile-Ife, Nigeria. His area of specialty is in Nutrition Epidemiology. He is currently pursuing his PhD in Public Health at the University of the Witwatersrand, Johannesburg, South Africa.