According to the graphic:

While these figures illustrate the incredible size of modern megacities, recent population data shows that the actual numbers are often even larger..

The global significance of megacities

Megacities are more than just population centres. They are hubs of economic power, cultural exchange, and innovation. Yet, their rapid expansion also creates pressing challenges:

As a result, regions closer to the poles, like Europe and North America, appear far bigger than they actually are, while equatorial continents, including Africa and South America , are dramatically shrunken.

Africa is about 30.3 million square kilometres, making it the second-largest continent on Earth.

It is three times bigger than Europe , yet many maps make it look nearly the same size.

The United States , China, India, and most of Western Europe could all fit inside Africa’s landmass at once.

“One such scholar is the renowned philosopher and social theorist Joseph-Achille Mbembe… he's been in South Africa for over 20 years, and even at that level, he still struggles with visa issues. Something as archaic as visa issues,” she told host Ismail Akwei.

“There is one particular scholar, she is at UCT [University of Cape Town]. She said the discrimination is so subtle that you even start to question your own sanity and asking what is exactly happening? But she said that what she has learned over time is not to ruffle any feathers but to take on an extra working load. So when everybody else is going home, it's the weekend, they're relaxing, you'll find the foreign academics, they're working overtime. They are teaching extra classes. They are working out of their minds to publish more to contribute so that they don't feel like a burden. 

“It's almost like being a child that has been adopted into a family but never accepted, and so you're made to feel that you need to work for the grace of being in this household. You need to prove that you are thankful,” she added.

Dr Simba said the research team had to hire a psychologist as support for the project because of the emotions that came from just talking about these issues. 

Watch the attached video for the full interview with Dr Precious Simba.

In general, the recommended daily intake can range from 2,100 to 4,800 calories for adult men and from 1,750 to 3,400 calories for women. In food terms, that ranges from the equivalent of 35 McDonald's chicken nuggets per day at the low end to 96 at the top end. 

In 2022, the average American consumed the calorie equivalent of 10.6 McNuggets a day. In contrast, the average person in Burundi, Somalia, Lesotho, and Yemen consumed only around five nuggets' worth of calories each day. 

Over time, the amount of food available to most people, and therefore the amount they eat, has been rising. This is a result of poverty reduction as well as improvements in the way we produce and transport food. In most cases, this is a benefit, although in some wealthy countries, a surplus of food has led to serious health problems.

The inequality across the globe is not a recent trend, but a long-term challenge. According to the FAO's 2023 State of Food Security and Nutrition report , over 3.1 billion people, which is nearly 40% of the global population, cannot afford a healthy diet. Even more concerning is that this number has risen by 134 million since 2019, driven by overlapping crises: COVID-19 pandemic fallout, climate-induced harvest failures, inflation, and economic slowdowns.

These figures expose a multi-layered nutritional inequality, where calories are not just unequally distributed, but also increasingly inaccessible for the low-income group. A 2023 World Bank analysis revealed that in some low-income countries, households allocate up to 60% of their income to food.  

However, progress in some parts of the world has been rapid. The chart comparing calorie intake in 1980 vs. 2022 shows Vietnam and Ghana making significant gains, with Ghana's per-person calorie consumption more than doubling. This success is rooted in long-term agricultural investment, better food distribution, and poverty reduction strategies. Ghana, for example, has expanded public agricultural extension services and promoted farmer cooperatives.

Kenya saw a 10.2% decrease in average calorie intake, despite GDP growth and urbanisation. This reflects deeper structural problems, including rising food import dependency, regional inequality, and stagnant rural incomes. According to the report , rural communities have seen stagnation in dietary diversity and food availability.

Meanwhile, another graph shows China's dramatic rise in calorie intake over the past four decades, which closely aligns with its GDP growth. In the 1980s, China implemented market-oriented agricultural reforms, lifting millions out of hunger. Today, China also strategically uses international trade agreements and grain reserves to stabilise food prices. Other countries, including Mali, which has suffered from widespread violent conflict, and Indonesia, have seen less dramatic progress. Today, Indonesia is rolling out the world’s most ambitious free meals programme to close its nutritional gap. More than 80 million people are expected to benefit by 2029.

While undernutrition remains a critical issue in parts of the Global South, a different concern arises in high-income countries: overnutrition and obesity. The WHO warns that the worldwide prevalence of obesity more than doubled between 1990 and 2022. In the UK, for example, over one-third of adults are obese, driven in part by ultra-processed diets.

However, despite the concerns of unhealthy overeating, the biggest problem currently facing the world remains undernourishment. The success stories of the past thirty years demonstrate that it is a problem that can be conquered, but the failures indicate that its demise is far from guaranteed.

*Obviously consuming all your calories in the form of chicken nuggets does not represent a healthy diet. McDonald’s nuggets are used only as an example, other brands have similar nutritional profiles.