Body Composition, Fat Distribution and Obesity: Impact in South Asians

By Annaswamy Raji, MD

Obesity is a growing problem all around the world. It is associated with many metabolic complications, including diabetes and heart disease. On a very simple level, body weight depends on the balance between number of calories consumed, stored and burned. Each of these is influenced by the person’s combination of genes, environment and behavioral components.

Health care providers all around the world use body mass index (BMI), which is an approximate measure of body fat in a person based on their height and weight.

According to World Health Organization, India will have the highest number of people with type 2 diabetes by the year 2025 AD (57 million), followed by China (38 million) and the USA (22 million). The greatest increase (195%) in the number of people with type 2 diabetes between 1995 and 2025 is expected to occur in India. Researchers have shown higher rates of diabetes and heart disease in Asian Indians migrated from rural to urban India, and to developed countries like the USA and United Kingdom. We don’t have many studies that look at risk factors in rural and urban Asian Indians, or migrant Asian Indians in the USA A recent study found that a high number of Asian Indians in the USA have diabetes, prediabetes, and the metabolic syndrome.

South Asian Americans are the fastest growing immigrant group in the United States. Overweight (adults: 38% - 57%, children: 18% - 43%) and obesity (24%) rates in Asian Americans, especially South Asian Americans, are increasing.

Our group and others have compared Caucasians (non South Asians) to South Asians. South Asians have more fat around the middle and many risk markers for heart disease and diabetes. Body composition and where the fat lies play important roles in causing diabetes and heart disease. These important issues need to be considered in patients of South Asian ancestry. All these studies tell us that looking at BMI alone in South Asians may not be enough to assess the risk factors for diabetes and heart disease. It appears that the BMI cutoffs for obesity are different from that of Caucasians. Researchers are looking to define obesity cut points (BMI and waist circumference) in multiethnic populations to better assess and treat metabolic complications in non-European populations. For now the World Health Organization (WHO) suggests that obesity be diagnosed at a BMI of 27 in an Asian population.

The South Asian population in the USA is relatively young and very diverse. Therefore there is a need for early and culturally appropriate intervention. Education and lifestyle changes (nutrition and physical activity) are needed to prevent metabolic complications.

The bottom line is this. If you are Asian-American, you are at risk for metabolic complications at a lower BMI than a person of European ancestry. Get in to see your doctor at least on a yearly basis to document that you don’t have diabetes, high blood pressure, high cholesterol, or other risk factors for premature heart disease. And follow the suggestions in this issue of Power of Prevention® Magazine to keep your weight down.

Annaswamy Raji, MD, M.M.Sc, is the Director of Diabetes and Metabolism at Parkland Medical Center in Derry, NH, and Assistant Professor at Harvard Medical School, Boston, MA. She is Board certified in both internal medicine and endocrinology. She obtained her fellowship in endocrinology at the Brigham & Women’s Hospital Boston, MA, and Masters in Medical Science from Harvard Medical School. Dr. Raji is a trained clinical endocrinologist and a clinical investigator with primary interest in clinical research in the areas of insulin resistance, diabetes and obesity and was the Director for program for weight management at the Brigham & Women’s Hospital until April 2009.