Mumbai: People of normal weight are far less likely to die from any cause compared to individuals who were overweight or obese, says a recent study on more than a million Asians.
The research, conducted as part of the Asia Cohort Consortium, included health status and mortality information on more than 1.1 million individuals from east and south Asia.
In the cohorts (study groups) of East Asians, including Chinese, Japanese and Koreans, the lowest risk of death was seen among individuals with a Body Mass Index (BMI) in the range of 22.6 to 27.5, which is considered normal to slightly overweight.
One of the study groups from India, the Mumbai Cohort Study, was led by Prakash C. Gupta, director of Healis-Sekhsaria Institute for Public Health.
"Despite the growing concerns regarding the gradual transition towards increasing rates of obesity, under nutrition remains a major health problem in India and being underweight is even more dangerous," he said.
Gupta mentioned that among all of the Asian populations studied, the risk of death was increased by a factor of 2.8 among those who had a BMI of 15 or less.
"Based on the findings in this paper, in addition to a standard public health message of not being obese, we formulate the new key public health message for not being underweight either," Gupta recommended.
BMI (Body Mass Index) is defined as weight in kilogrammes divided by the square of height in metres.
East Asians with a raised BMI of 35.0 or higher had a 50 percent higher risk of death. The same was not true for Indians and Bangladeshis, indicating that a high BMI did not affect all ethnic groups in a similar way.
The study was led by Wei Zheng, professor of cancer research at Vanderbilt Ingram Cancer Center, Tennessee; Paolo Boffetta, professor of Mount Sinai School of Medicine in New York and John D. Potter, senior adviser of public health sciences division at Fred Hutchinson Cancer Research Center in Seattle.
The authors concluded that the study provides strong evidence supporting the biologic plausibility that excess weight contributes to a higher risk of death which confirms that most people are at a higher risk for dying early if they are obese and is a clear message not to gain weight as we age.
At the same time being underweight is also not desirable, they noted.