The Rise of Obesity in Latin America and Its Complex Determinants
Obesity has escalated into a pressing public health crisis in Latin America, propelled by a complex interplay of systemic factors. Grasping and tackling these factors is crucial to combatting this burgeoning epidemic. This article sheds light on this urgent issue by drawing from the study’ Determinants of Obesity in Latin America,’ featured in the Nature Metabolism journal.
Obesity (body mass index (BMI) ≥ 30 kg/m²) is a significant global public health concern, leading to a range of comorbidities and premature death. The straightforward definition of obesity as a disease characterized by excessive body fat fails to fully capture the severe health implications it poses for individuals or the substantial financial burden it places on societies. Obesity is responsible for heightened rates of type 2 diabetes mellitus (DM), hypertension, dyslipidemia, steatohepatitis, polycystic ovary syndrome, depression, certain types of cancer, and several other disorders. According to the 2023 World Obesity Atlas, the prevalence of obesity is set to surge across the globe in the next decade, particularly among children and adolescents. As a result, obesity has emerged as a critical focus of the global public health agenda, prompting investments from various sectors to devise strategies to curb this devastating health crisis.
Differences in Obesity Demographics Worldwide
However, the increase in obesity rates varies when comparing populations from high-income and low- or middle-income countries (developed and developing countries, respectively). Historically, increases in obesity rates in developing countries occurred later, but recently, these countries have experienced the sharpest rise in obesity prevalence, especially among the youngest. This rapid increase cannot be explained by genetic factors or individual choices but rather by a combination of structural and contextual factors called systemic determinants.
Despite efforts and significant advances in understanding what influences the onset of obesity and how to prevent and treat it, obesity rates continue to proliferate, with some lower-income countries showing the highest increase and no country showing a decrease in obesity prevalence. Why is this happening? Is it because we do not know enough about obesity, or is the way we apply this knowledge ineffective or insufficiently diffused? Are we neglecting specific populations of solutions that could locally or globally slow down the obesity epidemics? These are essential questions that scientists working on obesity in developing countries frequently ask.
The Burden of Obesity in Latin America
The role of the environment and other systemic factors influencing body fat gain throughout life is well-documented, with dietary practices and a sedentary lifestyle being only part of the underlying determinants. International organizations and individual countries have made significant efforts to promote changes to counteract obesity. However, these efforts have not been sufficient to overcome the increases in obesity prevalence in socially disadvantaged populations. To address this, we must redefine the main determinants of obesity in countries with high inequality rates and diverse cultural and ethnic backgrounds, identify these determinants, propose strategies to decrease health disparities and anticipate ways to lead to more effective prevention and treatment. This requires the commitment of multiple sectors of society and collaboration between developed and developing countries. Tailored, realistic actions should be coordinated locally with scientists, politicians, investors, and public opinion, highlighting the need for collective efforts in this battle against obesity.
In 2020, it was estimated that 14% of the world’s population lived with obesity, projected to rise to 24% by 2035, including children, adolescents, and adults. Historically, higher rates of obesity in children and adults have been reported in developed countries compared to developing ones. However, recent trends show a steeper rise in developing countries. The historical scenario of obesity has changed in this century in a manner strongly related to socioeconomic status and sex distribution. In the developing world, a shift towards obesity within the lower socioeconomic strata has been observed as a country’s gross national product increases, suggesting that inequality is an underlying contributor to the obesity trend in these countries.
Obesity Demographics in Latin American Countries
Concerns about the rapid increase in obesity rates in developing countries extend beyond the disease’s prevalence. Suboptimal access to healthcare by many individuals living in economically disadvantaged countries is expected further to reduce their quality of life and life expectancy. The long-term costs of treating comorbidities also limit patient compliance and burden public health systems, contributing to lethal outcomes. Ineffectiveness in preventing and managing obesity has been widely reported, regardless of economic development, but in the developing world, this scenario is worse for numerous reasons.
Latin American countries like Mexico, Brazil, Colombia, Argentina, and Chile serve as reasonable proxies to understand obesity in developing countries, not only because of the increasing trends of obesity in these countries but also because of their most recent attempts to adopt measures to counteract these trends. All except Chile are upper-middle-income economies and among the most unequal countries in the world. They have extensive territories and large populations with diverse racial and ethnic backgrounds. A significant proportion of the population is overweight or obese: 75% of adults in Mexico, 55% in Brazil, 57% in Colombia, 68% in Argentina, and 74% in Chile. The prevalence among children and adolescents is also high: 39% in Mexico, 30% in Brazil, 22% in Colombia, 41% in Argentina, and 53% in Chile. While using these countries as proxies, other Latin American countries are expected to behave similarly, although regional differences are likely to occur. In 2016, except for Haiti, Paraguay, and Nicaragua, all other countries in Latin America and the Caribbean had at least 50% of their population living with overweight.
Mexico: A Case Study in Obesity
Among developing countries, Mexico has one of the highest rates of adult obesity. The geographical proximity and frequent migration between Mexico and the United States allow studies comparing populations of similar ethnic and racial backgrounds living in different environments. One study revealed that migration to a developed environment is associated with a lower BMI in children born and raised in Mexico versus those who moved to the United States. The north of Mexico, neighboring the United States, is wealthier, while the south is the poorest region. Interestingly, the areas with the highest adult obesity rates are the northwest (Pacific North) and the southeast (Peninsula), with the southeast also experiencing the highest rates of food insecurity. Although these regions are ethnically and economically diverse, similar obesity rates have been attributed to the omnipresent obesogenic environment, with widespread exposure to low-cost sugar-sweetened beverages (SSBs) and calorie-dense products. Obesity is more prevalent in adult women (41%) than in adult men (32%), particularly in urban populations.
Additionally, 88% of adult women and 74% of adult men have abdominal obesity, reflecting central rather than general adiposity, which is more strongly associated with cardiometabolic risk. Overweight/obesity is also high in children (39% in boys and 35% in girls) and adolescents (41% in both sexes). Notably, obesity is more prevalent in boys (22%) than in girls (14%) among children, and adolescent boys showed a significant increase in overweight/obesity from 2018 to 2022, while the prevalence remained relatively constant in other groups. Moreover, adolescents from rural areas had a steep rise in obesity burden over the last decade, although higher rates were registered in urban areas. This drastic change in obesity prevalence will have devastating consequences on developing obesity-associated diseases in the following decades, particularly among the least-privileged individuals.
Brazil: Diversity and Disparities
Brazil is a large and economically heterogeneous country with an ethnically diverse population, providing a scenario for comparative evaluations of factors influencing obesity rates. The current prevalence of obesity in Brazil is similar between adult men and women (20%); however, when considering both overweight and obesity, the prevalence is slightly higher in men (57%) than in women (54%). Education level strongly correlates with obesity prevalence, with those in the lower-education group showing a higher rate than those in the higher-education group. Also, a higher prevalence of obesity was observed in people from ethnic minorities and Black people compared to White people. Among teenagers, the prevalence of overweight and obesity is similar in boys and girls, but boys have a slightly higher prevalence of obesity. Considering that the southern part of Brazil is more developed and prosperous than the northern part, data stratification according to the geographical region allows hypothesizing on systemic determinants of weight gain. Obesity and overweight are more prevalent in teenagers in the south than in the north. In children, the prevalence of obesity is higher in boys than in girls, with significant regional differences.
Brazil has also been exposed to multiple waves of immigration in the past century, providing an opportunity to study how environmental changes affect obesity predisposition in genetically similar populations. For example, cohort studies of Japanese migrants in Brazil have highlighted the impact of a Western environment on increasing body adiposity, contributing to metabolic disturbances, cardiovascular disease, and increased mortality. Continuous monitoring of this Japanese-Brazilian population revealed the expected role of dietary factors in the incidence of metabolic disorders and the benefits of lifestyle intervention. However, other factors likely contribute to the outcomes.
Colombia and Argentina: Similarities and Challenges
Colombia and Argentina are the third and fourth most populated countries in Latin America, respectively. National surveys in Colombia showed that excess BMI increased by 10% in adults over a decade, reaching 57% in 2015. The burden of overweight and obesity is more severe in women than in men and middle- and high-income citizens compared to low-income ones. Regardless of their ethnic origin, overweight and obesity are prevalent in more than 50% of the population identified as Afro-descendant, Indigenous, or those without a self-identified ethnic belonging, supporting systemic rather than genetic factors as disease drivers. Obesity determinants in Colombia had a more substantial impact on children than adolescents. Similarly, excess weight increased significantly in children but less steeply in adolescents, showing a solid sex difference.
In Argentina, excess body weight is slightly more prevalent in adult men than women; however, obesity is more prevalent in women than men. A higher education level is associated with protection from obesity in Argentina, as people with a middle-school degree had lower obesity prevalence than less-educated individuals. Household income is also associated with obesity, with higher prevalence in the lowest income quintile. The scenario is more concerning in the age group between 5 and 17 years, where overweight is high in both sexes. Obesity is more prevalent in boys than girls, and unlike adults, household income was not inversely associated with obesity prevalence in this age group.
Chile: A Stark Contrast
According to the 2016-2017 health survey in Chile, 74% of the adult population is overweight or obese, with similar rates in women and men. When considering only obesity, prevalence is higher in women than in men. Among adults aged 30 to 64 years, the prevalence of overweight/obesity reached 84%. Higher obesity rates were observed in people with less education compared to those with higher education. Among children and adolescents, Chile has the most dramatic situation in Latin America, with high rates of overweight and obesity, particularly in boys. Regional differences also impact prevalence, with higher rates of obesity in children from rural areas.
Higher prevalence rates of obesity in boys were detected in Chile, Argentina, Mexico, and Brazil, while Colombia showed the opposite among adolescents. Among adults, obesity is more prevalent in disadvantaged groups, especially women. These findings suggest that the factors determining obesity may vary or impact individuals differently depending on age group and country, with boys, women, and underprivileged individuals usually at higher risk of developing obesity in Latin America.
Determinants of Obesity and Their Impact in Latin America
Despite evidence of genetically determined cases of obesity, monogenic disease is uncommon and does not explain the rapid increases in obesity rates worldwide. Similarly, the global trend towards increased obesity cannot be simplistically attributed to individual preferences for an energy-dense diet or reduced energy expenditure related to modern occupations and passive leisure activities. This fallacious argument disproportionately puts all the burden of obesity on individuals rather than systemic factors, which inevitably place these individuals in inequitable obesogenic conditions. Latin American countries feature characteristics that make individuals particularly exposed to these factors, which in turn appear to explain the dramatic rise in obesity burden in these countries.
Physical Environment and Obesity
Over the past 50 years, the world’s prevalence of obesity has almost tripled, and by 2035, most of the population will live with overweight or obesity. Such a dramatic change in the human phenotype can only be attributed to equally abrupt modifications in our living conditions. Among the many factors influencing the obesogenic environment, there is plenty of research supporting the role of changes in the physical environment in contributing to the obesity epidemic.
Latin America has faced unique and interconnected challenges related to pollution, water and food contamination with endocrine-disrupting chemicals (EDCs), climate change, deforestation, and urbanization. These challenges are particularly impactful in this region due to a combination of factors, including rapid industrialization, urbanization, agricultural practices, and environmental vulnerabilities. Latin American countries often grapple with air and water pollution from industrialization, vehicle emissions, and inadequate environmental regulations. Furthermore, agricultural practices in many Latin American countries involve using pesticides, herbicides, and fertilizers that may contain EDCs, contaminating soil and water and entering the food supply chain. Latin America is highly vulnerable to climate change impacts, including rising temperatures, extreme weather events, and altered precipitation patterns. Due to agricultural expansion and urban development, deforestation is also critical in Latin America. Finally, Latin America has experienced rapid and unplanned urbanization in recent decades, leading to numerous changes in the built environment, lifestyle, and dietary habits.
Food Exposure and Obesity
The burden of obesity in Latin America is partly due to the relatively rapid nutritional transition from a traditional diet to a ‘Westernized’ one. It is recognized that an eating pattern governed by the overconsumption of poor dietary quality, calorie-dense, ultra-processed foods (UPFs) is considered a significant driver of weight gain. Feeding patterns changed rapidly with the development of agriculture and farming, but it was during the past few decades that several socioeconomic factors radically transformed feeding behavior. Urbanization, globalization, women joining the labor force with less time for families to cook and share meals, and the development of a buoyant food industry to fulfill the needs of the growing and consumerist population changed the traditional human lifestyle, including in Latin America.
The definition of UPFs and the NOVA classification of foods based on their degree of processing triggered investigations regarding their impact on health outcomes. Systematic reviews and meta-analyses showed that UPF consumption is linked to overweight, obesity, and larger waist circumference in children, adolescents, and adults. UPF intake accounts for more than 50% of calories consumed in countries like the United States and the United Kingdom, while consumption varies in Latin American countries. High UPF calorie consumption rates in countries like Chile and Mexico align with high obesity prevalence, while Brazil and Colombia have intermediate rates of obesity and lower UPF consumption. Annual retail sales per capita of UPFs and drink products in 2013 showed a high correlation with the prevalence of obesity in Latin American countries. Consumption of UPFs in Latin American countries is higher in children than adults and is still on the rise, contrasting with the plateau seen in the United States and the United Kingdom.
Addressing the Obesity Epidemic in Latin America
Addressing the obesity epidemic in Latin America requires a multifaceted approach that considers the diverse and complex determinants. Interventions should focus on improving the physical environment, regulating food exposure, addressing economic and political interests, reducing social inequity, promoting scientific knowledge, and considering cultural and contextual behaviors.
Governments must implement comprehensive policies to promote healthier environments, regulate food marketing, and improve access to nutritious foods. Education and awareness campaigns are crucial to encouraging healthy lifestyles and reducing the consumption of UPFs and SSBs. Collaboration between multiple sectors of society, including scientists, politicians, investors, and public opinion, is essential to developing and implementing effective strategies.
Promoting physical activity and reducing sedentary lifestyles through urban planning and infrastructure improvements is vital. Ensuring access to green spaces, recreational areas, and safe environments for physical activity can help combat the obesogenic environment.
Tailored, realistic actions should be coordinated locally, considering each country’s unique challenges and characteristics. International partnerships and knowledge exchange can support the development of effective interventions and policies.
Also read: Brazil’s Escalating Dengue Crisis Leads to a Nationwide Emergency Vaccination Initiativ
Addressing the obesity epidemic in Latin America requires a holistic approach, focusing on systemic determinants and promoting coordinated efforts across various sectors of society. Understanding and addressing the complex factors driving obesity in the region, we can develop effective strategies to combat this growing public health crisis.
