According to the WHO, overweight and obesity are defined as abnormal or excessive fat accumulation that presents a risk to health. In adults, a body mass index (BMI) of 25 kg/m² or higher indicates overweight, while a BMI of 30 kg/m² or higher indicates obesity. Among children and adolescents, age- and sex-specific body mass index thresholds are used. Overweight and obesity arise from complex interactions between obesogenic environments, behavioural and psychosocial factors, and genetic susceptibility. These conditions substantially increase the risk of non-communicable diseases (NCDs), including type 2 diabetes and cardiovascular disease, and contribute to premature mortality. In children, overweight and obesity are also associated with psychosocial consequences that negatively affect quality of life and educational performance [15]. The economic burden of overweight and obesity is considerable and is projected to increase substantially in the coming decades [16].

Between 2019 and 2025, the prevalence of overweight and obesity in Africa has continued to rise, posing a growing public health challenge. WHO estimates indicate that adult obesity prevalence in the African Region reached 12% in 2022, increasing from 9% in 2010 [15]. Obesity prevalence was higher among women, at approximately 17%, compared with about 7% among men in 2022 [15]. However, substantial variation exists across countries. Among adult women, the prevalence of overweight and obesity was lower in Ethiopia at around 20% and markedly higher in Cape Verde at approximately 57% [17,18,19,20]. Among adult men, combined overweight and obesity prevalence ranged from about 21% in Ghana to 41% in Cape Verde, although several studies did not report separate estimates for overweight and obesity [19, 21].

Urban residence is consistently associated with higher levels of overnutrition. In Cape Verde, 51% of adults living in urban areas were overweight or obese by 2020, compared with 47% in rural areas [19]. Similar patterns have been observed in Ghana, where 27% of men in urban areas were overweight or obese compared with 12% in rural areas, and among women, where prevalence reached 44% in urban settings compared with 26% in rural settings during the period 2019 to 2023 [17, 21]. These disparities reflect differential exposure to energy-dense diets, sedentary lifestyles, and urban food environments.

Among children and adolescents younger than 19 years, the prevalence of overweight and obesity remains lower than in adults but is increasing. Studies published between 2019 and 2025 report prevalence estimates ranging from 3% in Ethiopia to 18% in Zambia. Across these studies, overweight prevalence ranged from 9% to 13%, while obesity ranged from 5% to 6% [22,23,24,25,26,27]. WHO estimates indicate that approximately three million children in Africa were overweight or obese in 2022, representing an increase of nearly 12% since 2000 [15]. This upward trend suggests a growing future burden of adult obesity and related NCDs.

Projections from the World Obesity Federation World Obesity Atlas 2022 indicate that, without effective intervention, the prevalence of overweight and obesity among African adults is expected to increase sharply by 2030. These projections underscore the urgency of implementing preventive strategies to avert further escalation of obesity-related morbidity, mortality, and health system strain across the continent [28].

Undernutrition comprises four main forms: wasting, defined as low weight for height; stunting, defined as low height for age; underweight, defined as low weight for age; and micronutrient deficiencies, reflecting inadequate intake of essential vitamins and minerals. Wasting substantially increases the risk of mortality through heightened susceptibility to infections, while stunting impairs physical growth and cognitive development in children. Micronutrient deficiencies further compromise growth, development, and physiological function by limiting the body’s capacity to produce enzymes, hormones, and other essential compounds [29]. Undernutrition most commonly arises in the context of food insecurity, defined as a lack of regular access to sufficient, safe, and nutritious food for normal growth, development, and an active and healthy life. Food insecurity is shaped by food availability, access, utilisation, and stability [30].

According to estimates from the WHO and UNICEF, undernutrition in Africa remains high relative to global averages. Although prevalence declined between 2012 and 2024, recent data suggest that these gains are stalling or reversing in several settings [31]. Across studies published between 2019 and 2025 that focused on children and adolescents younger than 19 years, the overall prevalence of undernutrition ranged widely, from 10.4% to 58.4%. Wasting prevalence reported in ten studies ranged from 3.8% in Tanzania to 42.9% in Ethiopia [20, 27, 32,33,34,35,36,37,38,39]. Stunting prevalence reported in thirteen studies ranged from 9.1% in South Africa to 45.8% in Ethiopia [20, 26, 27, 32, 34,35,36, 39,40,41,42,43,44]. Underweight prevalence reported in six studies ranged from 12% in Ghana to 23.3% in Ethiopia [20, 26, 34,35,36, 44]. Anaemia prevalence reported in five studies ranged from 19.2% in South Africa to 60.5% in Tanzania [26, 32, 43, 45, 46]. These estimates are broadly consistent with findings from studies published before 2019, indicating limited overall progress in reducing undernutrition over time [47,48,49,50]. Notably, none of the reviewed studies examined adult undernutrition, highlighting an important gap in current evidence.

Micronutrient deficiencies remain widespread across the region. More than half of all children and approximately two-thirds of non-pregnant women of reproductive age in Eastern and Southern Africa are deficient in one or more essential vitamins and minerals, reflecting persistently low dietary diversity [51,52,53]. However, population-level data on micronutrient status remain sparse. Among studies published between 2019 and 2025, one South African study reported vitamin D deficiency in 28.5% of adults, while a study from Uganda reported vitamin A deficiency in 8.9% of children younger than five years [36, 54]. These findings indicate substantial micronutrient gaps that remain poorly characterised at the population level.

Food insecurity has increased across Africa in recent years. The 2025 State of Food Security and Nutrition in the World report documented a rise in food insecurity prevalence from 17% in 2019 to 19% in 2022, reaching approximately 20% in 2025. If current trends persist, Africa is projected to account for around 60% of the global food-insecure population and nearly half of all undernourished people by 2030 [55,56,57]. Considerable heterogeneity exists across countries. Between 2019 and 2025, food insecurity prevalence ranged from 17% in Burkina Faso to as high as 88% in Sierra Leone, reflecting differences in food systems, economic conditions, governance, and climate vulnerability [58,59,60,61,62,63,64,65].

Armed conflict further exacerbates food insecurity and undernutrition in many parts of Africa. Evidence indicates that prolonged conflict substantially increases the likelihood of child undernutrition, with odds rising up to threefold in some settings, particularly in Central Africa [66]. As a result, undernutrition increasingly coexists with rising overweight and obesity. Between 2019 and 2025, studies reported a community-level double burden prevalence of approximately 12% in Tanzania and household-level prevalence ranging from 9% in Senegal to 17% in Ethiopia [20, 26, 67]. These patterns highlight a rapidly evolving nutrition landscape in which persistent undernutrition overlaps with increasing overweight and obesity across populations.

Climate change refers to long-term shifts in temperature and weather patterns, primarily driven by increased concentrations of greenhouse gases such as carbon dioxide and methane, largely originating from agriculture, energy production, and industrial activities [68]. In addition to greenhouse gases, particulate matter generated from biomass burning, agricultural practices, and household energy use acts as a short-lived climate forcer that accelerates climate change and directly affects human health [7]. Together, these environmental changes disrupt ecosystems that underpin clean air, safe drinking water, nutritious food supplies, and adequate shelter, posing growing risks to global health. Under current trajectories, climate change is projected to cause approximately 250,000 additional deaths annually between 2030 and 2050 from malnutrition, malaria, diarrhoeal disease, and heat stress alone [69].

According to assessments by the Intergovernmental Panel on Climate Change, Africa contributes only 2 to 3% of global greenhouse gas emissions but is already experiencing disproportionately severe impacts of climate change [7]. These impacts are amplified by low adaptive capacity in many African countries, including limited climate-resilient infrastructure, inadequate early warning systems, constrained financing for adaptation, and heavy reliance on rain-fed agriculture. As a result, climate risks increasingly threaten livelihoods, food security, health systems, and long-term economic development across the continent.

The scale of climate-related impacts has intensified in recent years. Between 2022 and 2023, the number of people affected by extreme weather events in Africa increased from 19 million to 34 million [70]. In 2023 alone, floods affected 23 countries, cyclones struck three countries, and five countries experienced heatwaves with temperatures exceeding seasonal averages by more than 20 °C [70]. Extreme heat in parts of northern Africa triggered wildfires, while severe drought and famine affected countries including Djibouti, Ethiopia, Kenya, Mauritania, Niger, and Somalia. These crises left approximately 23 million people food insecure and contributed to acute malnutrition among an estimated four million children [70, 71]. The true scale of these impacts is likely underestimated, as Africa has the lowest density of meteorological monitoring stations globally [70].

Urbanisation further interacts with climate and nutritional risks. Over the past two decades, Africa has experienced rapid urban growth, with an average annual increase of approximately 3.5% [72]. The proportion of the population living in urban areas rose from 36% in 2010 to 45% in 2024 and is projected to reach 50% by 2030 and 60% by 2050 [72]. Rapid and often unplanned urban expansion has strained infrastructure and services, widened social inequalities, and increased environmental pressures [72]. Concurrently, a nutrition transition has occurred, characterised by shifts away from traditional diets toward energy-dense, processed, and animal-source foods [73]. This tran