A Review of Obesity, Metabolic Syndrome and Epigenetics in South Asian (SA) Communities

South Asia is home to a remarkable portion of the world’s population, with about 1.9 billion people, making up nearly 24% of the global total. This region, which includes countries like India, Pakistan, Bangladesh, Nepal, Bhutan, Sri Lanka, and the Maldives, plays a vital role in shaping global demographics. One of the striking characteristics of South Asia's population is its youthful nature, setting it apart from many other parts of the world. In South Asia, roughly 28-30% of the population is under the age of 14, a larger proportion than the global average of 25%. This reflects a region with a high birth rate and a significant number of young people entering the workforce and education systems. Meanwhile, about 65% of South Asians fall within the working-age group (15-64 years), aligning with global trends. However, only 5-7% of the region’s population is over 65, compared to around 10% globally. This indicates that South Asia has a smaller elderly population, in contrast to many developed countries where longer life expectancy and lower birth rates are creating aging populations. These dynamics suggest that South Asia's youthful demographic will be central to its future development and economic growth. Introduction: South Asia is one of the most populous regions globally, and its population statistics are significant when compared to the global population. As of recent estimates: Percentage of Global Population from South Asia • South Asia accounts for about 25% of the global population. The region includes countries like India, Pakistan, Bangladesh, Nepal, Bhutan, Sri Lanka, and the Maldives. • The total population of South Asia is around 1.9 to 2 billion people, with India alone contributing to a large portion (about 1.4 billion). Age Distribution South Asia has a relatively young population compared to the global average, with a higher proportion of younger age groups. Here’s a comparison of the age distribution in South Asia vs the rest of the world. South Asia • 0–14 years: About 30% of the population. • 15–24 years: Around 20% of the population. • 25–64 years: Approximately 45%. • 65 years and older: Around 5%. Global Average • 0–14 years: About 25% of the global population. • 15–24 years: Roughly 15%. • 25–64 years: Around 50%. • 65 years and older: Around 10%. Key Points • South Asia has a younger population, with a higher percentage in the 0–24 age bracket compared to the global average. • The rest of the world, particularly regions like Europe and North America, tends to have a more aging population, with higher percentages in the 65+ age group. These demographic trends have significant implications for future economic development, healthcare needs, and social policies in South Asia and globally. Obesity is increasing globally, and South Asians (SA’s) are particularly vulnerable due to a combination of genetic, environmental, and lifestyle factors. Central obesity is prevalent among South Asians, leading to metabolic issues like insulin resistance and hypertension, even at lower body mass index (BMI) levels than seen in Western populations. This has prompted organizations such as the International Diabetes Federation (IDF) to adopt ethnic-specific waist circumference cut-offs for SAs. The "thin fat" phenotype, common in this group, refers to individuals who appear lean but carry excess visceral fat, raising their cardiovascular risk. Despite identifying some obesity-related genes like FTO and MC4R, research on South Asian populations remains limited compared to studies on Europeans. Traditional BMI cut-offs often underestimate health risks in this population, highlighting the need for targeted public health interventions to address rising obesity and metabolic disorders among South Asians.