With obesity rates rising at an alarming rate, according to a new World Health Organisation (WHO) study, South African researchers say the problem in this country – where more than two-thirds of women are overweight – is akin to a "new HIV epidemic" and calls for urgent measures, writes MedicalBrief.
In an editorial in the SA Medical Journal, the group respected scientists said the nation needed to pay attention, because “as with the HIV epidemic in the 1990s, we’re facing a calamitous threat to the health of the population that has been ignored for too long”.
Weight-related diseases have eclipsed TB and HIV as leading causes of morbidity and mortality. Type 2 diabetes, stroke and heart disease, conditions all directly linked to the disease of obesity, account for three of the top four causes of death nationally and incur massive health system costs.
Globally, more than 1bn people are now obese, with rates among children increasing fourfold across a 32-year period, according to recent analysis of the weight and height measurements of more than 220m people from more than 190 countries.
Around 1 500 researchers contributed to the study by the NCD Risk Factor Collaboration with the WHO, showing how body mass index (BMI) changed, globally, between 1990 and 2022.
Published in The Lancet, it found that over the period, obesity rates had increased fourfold among children, and doubled among adults.
The Guardian reports that for girls worldwide, the obesity rate increased from 1.7% of the world’s population in 1990, to 6.9% in 2022. For boys, the increase was from 2.1% to 9.3% over the same time period.
Obesity is defined in adults as having a BMI greater or equal to 30kg/m2.
For women, obesity rates worldwide increased from 8.8% to 18.5%, and for men, 4.8% to 14% across the same period. At the same time, rates of people who are underweight fell for both children and adults, meaning that obesity is the most common form of malnutrition across many countries worldwide.
The proportion of the world’s children and adolescents who were underweight fell by around one-fifth in girls and more than one-third in boys, while the proportion of the world’s adults who were affected by being underweight more than halved over the same period.
In total, 880m adults and 159m children were obese in 2022. Tonga, American Samoa and Nauru had the highest obesity rate, at more than 60%.
Vietnam had the lowest female obesity rate and Ethiopia had the lowest rate among men.
Island nations in the Pacific and the Caribbean and countries in the Middle East and North Africa had the highest combined rates of both underweight and obesity.
The statistics are a sign of worsening nutrition that’s also raising the risk of leading causes of death and disease such as high blood pressure, cancer and diabetes, reports Axios.
Senior researcher Professor Majid Ezzati, of Imperial College London, told the BBC: "In many of these island nations it comes down to the availability of healthy food versus unhealthy food.
"In some cases there have been aggressive marketing campaigns promoting unhealthy foods, while the cost and availability of healthier food can be more problematic."
He added that is was “very concerning” that the epidemic of obesity evident among adults in much of the world in 1990 was now mirrored in school-age children and adolescents.
“At the same time, hundreds of millions are still affected by under-nutrition, particularly in some of the poorest parts of the world. To successfully tackle both forms of malnutrition it is vital we significantly improve the availability and affordability of healthy, nutritious foods.”
Ezzati, who has been looking at global data for years, said he was surprised by the speed at which the picture has changed, with many more countries now facing an obesity crisis, while the number of places where people being underweight is regarded as the biggest concern, has decreased.
Study co-author Dr Guha Pradeepa, from the Madras Diabetes Research Foundation, said major global issues risk worsening malnutrition caused by both obesity and being underweight.
“The impact of issues such as climate change, disruptions caused by the Covid-19 pandemic and the war in Ukraine, risk worsening both rates of obesity and underweight, by increasing poverty and the cost of nutrient-rich foods.
“The knock-on effects of this are insufficient food in some countries and households, and shifts to less healthy food in others.”
Dr Tedros Adhanom Ghebreyesus, director-general of the WHO, said: “Getting back on track to meet the global targets for curbing obesity will take the work of governments and communities, supported by evidence-based policies from WHO and national public health agencies.
“Importantly, it requires the co-operation of the private sector, which must be accountable for the health impacts of their products.”
In South Africa, say the local scientists, as with HIV in the early 2000s, tools to prevent and treat obesity are available, but too often, are being ignored or obfuscated through government inaction, industry interests, and societal inertia.
They write:
Additionally, as with HIV, SA has waited too long to convert effective interventions into effective public health strategy.
Instead, we remain trapped in a cycle of apathy while blaming and stigmatising those affected.
The medical establishment has not always been an ally in combating the obesity health emergency. A poor understanding of the physiology of the disease, the endocrinological complexity of fat tissue, and the contribution of diet and exercise to weight gain, has led healthcare providers to preach the common refrain of “eat less and move more”.
This serves to further perpetuate shame and stigma for those with the disease, even as it is now well understood to be ineffective alone for most of those affected.
An effective response to this established disease crisis is vital. There are two important next steps. First, to apply the lessons from the HIV epidemic to reduce obesity-related stigma and facilitate widespread access to novel anti-obesity therapies using a public health approach; and second, to establish robust advocacy efforts to ensure structural determinants of the disease, including food supply and the built environment, promote, rather than undermine, health.
Much as combination therapy was a game changer for the HIV response, modern obesity medicine has demonstrated that novel medications and/or surgery are critical elements to achieve sustained weight loss and improved health outcomes.
For example, new classes of medications, like the glucagon-like peptide (GLP)-1 receptor agonists, effectively control the disease, improve glycaemic control and reduce cardiovascular events, but are prohibitively expensive, prone to massive repeated supply shortages, and unavailable from state clinics and most medical aids.
SA is uniquely positioned to build upon the success of HIV and TB programmes to change this situation, by including simplification of access alongside generic manufacture at scale to facilitate price reduction.
Notably, these interventions do not conflict with lifestyle recommendations, with recent evidence suggesting greater efficacy when these drugs are used in combination with lifestyle changes.
The Standard Treatment Guidelines and Essential Medicines List contains no approach to the disease of obesity, and medication and surgical approaches were removed from the 2023 National Obesity Strategy, which barely mentions treatment, apparently owing to cost.
Obesity science is also teaching us how biomedical interventions are unlikely to be sufficient to tackle this epidemic alone. The obesogenic environment – structural societal conditions including both our food system and our built environment – is an important driver of the rise in obesity levels in the past 40 years in SA and elsewhere.
For example, the introduction of cheap, highly and ultra-processed food and sugar-sweetened beverages, offered in slick venues and spaza shops accompanied by marketing campaigns often aimed at children, alongside a built environment that hinders sufficient physical activity, are major driving forces.
Focusing on our food supply, facilitating access to a diversity of affordable fresh, healthy, unprocessed food and the means to prepare it, and ensuring the public is aware of the dangers of highly processed and ultra-processed food, is a necessary step.
It is unlikely these systematic changes will be possible without firm government and regulatory intervention.
One chilling difference from HIV is that the viral vector did not have a massive unregulated marketing machine behind it. Distressingly, there has been little sign of urgency on the government’s part to take up the issue of food advertising, quality and affordability, and some of these industries clearly have the ear of senior officials, as in other countries.
Debates on where to focus resources, programming, and attention on the prevention or treatment of clinical obesity are also reminiscent of the early HIV epidemic. Then, many prevention advocates regarded people with HIV as sad casualties of failed prevention programmes, too expensive and complex to treat.
The language “medicalising a social problem” has similarly started to creep into the discourse about obesity and its management, occasionally with a moral touch of “they brought it on themselves”.
Allowing this language to persist would be a dreadful mistake. To destigmatise obesity, and effectively combat the obesity epidemic, it will be important to maximise the use of all prevention and treatment strategies simultaneously.
The activist and medical communities were critical in advocating for the introduction of antiretroviral drugs and provision of healthcare that allowed people with HIV to live healthy, productive lives.
We have a moral imperative to advocate just as vigorously for individuals with obesity, and it is past time for our government and medical community to develop a laser-like focus on responding to obesity. This will require policy, legislation, programming and funding actions that facilitate access to innovative medical tools for obesity and deliver these in an environment that promotes healthy food choices and active lifestyles accessible to all.
SA’s HIV programme is often held up as the global model, thanks to decades of health activism, community engagement and science-based policy, along with government resources and commitment.
Proposed approaches to address the obesity epidemic in SA
Adopt strategies to address food supply healthfulness, affordability, advertising and labelling
• Strengthen front-of-package warning label legislation
• Increase sugar-sweetened beverage tax to meet WHO recommendation (20%)
• Assess additional ‘sin tax’ approaches to fast food and all foods with a front-of-package label (e.g, ‘polluters pay’ approaches), and ensure that these benefit the ‘harmed’ population
• Regulate importation of ultra-processed foods further into the SA market
• Limit direct-to-consumer advertising by Big Food to youth
• Ban sale of ultra-processed or highly processed foods/sugary drinks at schools
• Subsidise production and distribution of healthy and unprocessed food
• Address ‘food deserts’ through thoughtful policy and incentives
Advance a public health approach to weight management
• Establish national obesity indicators and regularly assess progress, including monitoring and responding to food deserts where unprocessed food is unavailable and/or unaffordable
• Ensure that school food programmes are prioritised within education budgets, and healthy
• Establish primary care models of integrated holistic cardiometabolic healthcare
• Engage communities in design of primary care models of obesity care
• Establish a national research programme to address SA’s questions, priorities, and data gaps pertaining to the obesity crisis, that includes establishing better biomarkers and risk predictors beyond the BMI
Promote accessibility and affordability of clinical interventions to support weight management
• Propose and regularly update evidence-based guidelines for obesity management
• Specify an appropriate mix of medical and surgical interventions for public/private sectors in guidelines (prescribed minimum benefits)
• Include appropriate AOMs in the national formulary
• Promote generic manufacture of AOMs at scale
• Simplify AOM access requirements
Address the built environment to promote increased levels of physical activity
• Improve security and safety in communities to enable physical activity
• Propose city planning guidelines to ensure adequate safe public parks and spaces to promote physical activity for leisure and commuting
• Increase school-based physical activity programming
• Promote employer-based physical activity standards and/or incentives, including subsidised gym membership, equipment, bicycles
Intervene for stigma reduction, community awareness and health professional education
• Address cultural norms around ‘normal’ weight and body/health perceptions that may incentivise/disincentivise weight interventions, through education and advertising campaigns/public service announcements
• Support civil society initiatives that educate communities regarding food choices, stigma reduction
• Mandate healthcare provider continuing health professional curricula for obesity stigma reduction
• Regulate Big Food’s involvement and influences on health professionals’ attitudes to healthy lifestyles by banning contributions to conferences, research funding, educational activities
Study details
Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults
NICD Risk Factor Collaboration
Published in The Lancet on 29 February 2024
Summary
Background
Underweight and obesity are associated with adverse health outcomes throughout the life course. We estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from 1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories.
Methods
We used data from 3663 population-based studies with 222 million participants that measured height and weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children and adolescents (age 5–19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the individual and combined prevalence of underweight (BMI <18·5 kg/m2) and obesity (BMI ≥30 kg/m2). For school-aged children and adolescents, we report thinness (BMI <2 SD below the median of the WHO growth reference) and obesity (BMI >2 SD above the median).
Findings
From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in 11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and 140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%) with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and 42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents, the increases in double burden were driven by increases in obesity, and decreases in double burden by declining underweight or thinness.
Interpretation
The combined burden of underweight and obesity has increased in most countries, driven by an increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of underweight while curbing and reversing the increase in obesity.
The Lancet article – Worldwide trends in underweight and obesity from 1990 to 2022 (Open access)
The Guardian article – More than a billion people worldwide are obese, research finds (Open access)
Axios article – Worldwide obesity tops 1 billion (Open access)
BBC article – More than a billion people obese worldwide, research suggests (Open access)
SA Medical Journal article – Obesity is South Africa’s new HIV epidemic (Creative Commons Licence)
See more from MedicalBrief archives:
Schoolchildren’s obesity legacy from Covid – UK study
Obesity should be treated as urgent ‘gateway’ medical condition, say experts
Obese COVID patients twice as likely to be admitted to ICU or die — Swedish cohort study
More years of obesity means higher risk of cardiometabolic disease