Childhood Overweight and Obesity in Nigeria: A 20-year Systematic Review and Meta-analysis of Prevalence, Sex Differences and Temporal Trends

For centuries, the word malnutrition brought to mind images of hunger and starvation, a lack of food that left children thin and weak. This was the primary nutritional struggle for much of the world. But as economies grew and societies shifted away from simple farming, a different problem began to take hold in wealthier nations: too much food, leading to children carrying extra weight. In many developed places, the old problem of hunger has largely faded, replaced by this new challenge. Yet, in many parts of Africa and Asia, the old problem of hunger has not disappeared; it still affects millions. Now, these same regions are seeing a steady rise in the number of children who are overweight or obese. This creates a difficult double burden where a population must fight against both hunger and excess weight at the same time.

Carrying too much weight as a child is not just about appearance. It is a powerful warning sign for serious health issues that can last a lifetime. Children who are overweight are at a much higher risk of developing high blood pressure, heart disease, and diabetes later in life. These conditions, known as non-communicable diseases, are now the leading cause of death in many countries, surpassing infectious diseases. Because the body tends to carry these health risks from childhood into adulthood, stopping the trend early is the most effective way to protect future generations. In Nigeria, a country with a large population of young people, understanding how widespread this issue is, and how it is changing, is critical for planning the health of the nation.

A team of researchers set out to map this changing landscape in Nigeria. They did not conduct a single new experiment but instead gathered and analyzed sixty-seven existing studies published over a twenty-year period, from 2005 to 2024. These studies involved more than 67,000 children and teenagers across the country. The researchers looked for studies that measured height and weight to calculate a body mass index, a standard way to determine if a person is at a healthy weight for their age. They focused only on research that used clear, consistent methods to define overweight and obesity, ensuring that the data they combined was reliable. Their goal was to find out how common the problem is, whether it affects boys and girls differently, and if the situation is getting better or worse over time.

When the researchers combined the data from these fifty-two high-quality studies that met their strict criteria, they found that roughly 7.7 percent of Nigerian children and adolescents are overweight or obese. While this number might seem small at first glance, the researchers noted that the situation is far from uniform. The studies they reviewed varied wildly in their findings, with some reporting no cases at all and others finding rates as high as 33 percent. This huge variation suggests that the problem is not the same everywhere; it depends heavily on where a child lives, their age, and their background. The data showed that the studies were not evenly spread across the country. Most research came from the southern regions, particularly the southwest, while very few studies came from the north. This gap in information means the current picture is incomplete, but it is the best summary available from the existing evidence.

One of the most consistent patterns the researchers found was a difference between boys and girls. Girls were significantly more likely to be overweight or obese than boys. In the studies that provided a breakdown by gender, about 9.4 percent of girls fell into this category, compared to 5.8 percent of boys. This finding is notable because it runs counter to trends seen in some other parts of the world, where boys often have higher rates. The researchers suggest this difference in Nigeria could be linked to biological changes during puberty, differences in how boys and girls are raised regarding physical activity, or cultural ideas about body size that might limit outdoor play for girls.

Perhaps the most urgent finding of the review is the direction the trend is taking. The researchers analyzed the data year by year and found a clear, steady increase in the prevalence of childhood overweight and obesity over the two decades they studied. For every year that passed, the likelihood of a child being overweight or obese increased slightly but significantly. This upward trajectory indicates that the problem is not static; it is growing. The researchers attribute this rise to the rapid changes happening in Nigeria, including faster urbanization, a shift toward more energy-dense foods, and more sedentary lifestyles where children spend less time moving and more time sitting.

The study also challenged some common assumptions about where this problem exists. It is often believed that childhood obesity is strictly an urban issue, affecting only children in big cities with access to fast food and less space to play. However, the data showed that children in rural areas might face an even higher risk, though the researchers cautioned that there were very few studies from rural settings to confirm this with certainty. The few rural studies they did find showed higher rates than the urban ones, suggesting that the problem is spreading beyond the cities. Similarly, while the South-South region showed the highest rates in the data, the lack of studies from the North makes it difficult to say for sure if the problem is truly worse in the south or if it is simply that the north has been studied less.

The researchers concluded that childhood overweight and obesity is a significant and growing public health challenge in Nigeria. The evidence points to a need for new strategies that are sensitive to gender differences and that reach children in schools and communities, not just in cities. Because the problem is increasing, the authors argue that Nigeria needs to integrate the monitoring of children's weight into its national health plans. They suggest that schools are a practical place to screen children, teach nutrition, and encourage physical activity. Without targeted efforts to screen and support children now, the country risks facing a much heavier burden of heart disease and other chronic conditions in the future. The review serves as a clear signal that while the country still battles hunger, it must also act quickly to address the rising tide of excess weight before it becomes an even larger crisis.