A pair of studies published in The Lancet medical journal on Monday (March 3) have estimated that 380 crore people, or over half of all adults globally, and 74.6 crore people, or a third of all children and adolescents worldwide, will be overweight or obese by 2050. The studies have calculated the prevalence of overweight and obese individuals (adults and children) globally, with forecasts till 2050. As of 2021, nearly 211 crore people, about 45% of the global population, were reported as obese or overweight. About half of these people were found in just eight countries: China (40.2 crore), India (18 crore), the USA (17.2 crore), Brazil (8.8 crore), Russia (7.1 crore), Mexico (5.8 crore), Indonesia (5.2 crore), and Egypt (4.1 crore). What do the studies say about obesity in India? India ranks on top of many lists concerning these metrics, with both studies estimating that the country’s number of overweight and obese people will keep increasing till 2050. India may even overtake China in absolute numbers in certain categories. Adults: The absolute number of adults aged 25 and older in India diagnosed as "overweight" or "obese" increased between 1990 and 2021. India is projected to have the second-largest overweight or obese population in 2050, having ranked fourth globally in 1990. Older adolescents: By 2021, India had overtaken China to become the country with the largest number of overweight and obese older adolescents, aged between 15 and 24. The study on children and adolescents estimates that this number will only grow further. Children: The number of obese or overweight children in India has grown tremendously, with India currently ranked second to China. The study shows that the gap between the two countries will narrow by 2050: the number of overweight and obese children in neighbouring China is expected to stabilise, while the number in India will continue to grow. Who is considered to be obese? The study on obese and overweight adults categorises adults with a Body Mass Index (BMI) – the ratio of a person’s weight to their height squared – as obese if their BMI is greater than 30, and overweight if their BMI is between 25 and 30. In the parallel study, the scientists considered the International Obesity Task Force’s weight recommendations by age and gender for children and young adolescents aged 5-17. In January, a Lancet commission had proposed changes to the definition of obesity to introduce two new categories: ‘clinical obesity’ and ‘pre-clinical obesity’. The new definition included physical parameters like height, weight, waist circumference, muscle mass, and the functioning of various organs. Under the revised definition, the physician will consider at least two body size parameters among among BMI, waist circumference, waist-to-hip ratio, and waist-to-height ratio, to make a clinical obesity diagnosis. They will check for symptoms like breathlessness, wheezing, sleep apnoea, metabolic dysfunctions, changes in the reproductive system, heart failure, chronic fatigue, knee and joint pain, and any hindrances to normal day-to-day life. They may also consider a person’s daily activity level before arriving at a diagnosis. Thus, a person ranking high on body size parameters but experiencing none of the consequences of obesity will be categorised as having pre-clinical obesity. The new definition aims to comprehensively determine the impact of obesity — a person with a BMI less than 30 may still have a lot of abdominal fat and face the complications of obesity, whereas someone with muscle mass and a BMI over 30 may be healthy. What may be the impact of the growing numbers of overweight and obese individuals? First: The sheer number of overweight or obese children, who will grow up to be adults who are overweight or obese. “With the global prevalence of obesity in children and adolescents having increased by 244% in the past 30 years and having a forecasted increase of 121% in the next 30 years, trends in adult obesity prevalence are unlikely to abate,” the study said. Second: The rapid increase in obesity among children and adolescents increases the risk of early onset of several lifestyle diseases, such as Type 2 diabetes, heart diseases, and certain types of cancer. Third: In many countries, especially high-income countries, an aging population and fewer childbirths mean managing obesity-related chronic conditions at advanced ages. Aging patients with obesity generally need more elective surgeries and have higher treatment costs because of suboptimal outcomes. Close to a quarter of the world’s population with obesity in 2050 will be older than 65 years, the study on adults said. Fourth: A higher incidence of obesity leads to an increased vulnerability to infections and severe diseases, resulting in higher healthcare spending. Fifth: Obesity is often coupled with persistent childhood under-nutrition and pervasive infections, especially in the low and middle income countries. This threatens to cripple the healthcare systems. Further, childhood undernutrition triggers adaptive mechanisms such as the storing of fat, which can lead to obesity and increased risk of lifestyle diseases later in life. What is the reason behind the obesity epidemic? Both studies attribute the shift towards consuming calorie-dense foods high in sugar, salt, and fat as a major cause. In countries with a high prevalence of obesity, this results from traditional local food supply systems being replaced by big food distribution, offering high-calorie foods with long shelf life. The studies flagged the shift from high-income to low- and middle-income countries by multinational food and beverage corporations as a major concern. In these countries, “population growth, improvement in per-capita income, and weaker regulations have created favourable markets for expansion.” The largest annual growth in per capita sales of ultra-processed foods and beverages between 2009 and 2019 was reported in Cameroon, India, and Vietnam. What needs to be done? First, protecting local food systems in low- and middle-income countries from being overrun by large food companies. The studies call for coordinated action by maintaining local agricultural patterns and traditional food preparations, while modernising these food systems by skilling, market reforms, and industry entrepreneurship. This will allow them to compete with the global companies. Additionally, taxing unhealthy foods such as sweetened beverages reportedly showed some success. Second, governments and health systems must invest in clinical management and the treatment of obesity and related lifestyle conditions in countries where the obesity epidemic is already at its peak. Third, there is a need for national-level policy, strategy, or action plans to address overweight and obesity. The studies indicate that despite obesity being on the global health agenda for over two decades, only 40% of countries have such policies. This level drops to 10% in low- and middle -income countries. Fourth, with the prevalence of obesity on the rise in low and middle income countries, there is a need to study intervention strategies in low income conditions. Most obesity intervention studies to date have been in high-income settings. Fifth, the use of the new class of obesity drugs GLP-1 receptor agonists such as semaglutide and terzapatide. In the past, the uptake of obesity drugs has been slow owing to possible side-effects including suicidal ideation and contraindications for conditions like cardiovascular diseases common among the obese. The new generation of medications seems to have mitigated these constraints, but access and cost remain a challenge. An attempt was made in 2023 to place anti-obesity drugs on the World Health Organisation’s list of essential medicines to ensure access, but it was rejected due to uncertain long-term clinical benefits. With market exclusivity for several new anti-obesity drugs are soon to expire and cheaper, generic versions will likely become available.
