Check out this study- http://www.cdc.gov/pcd/issues/2012/11_0284.htm#Results
Very interesting findings: In our study of South Asian Americans, the prevalence of overweight and obesity were high, and underestimation of weight status and the consequences of being overweight were common. Misperceptions about weight status and weight-related health consequences were particularly common among participants who had a BMI between 23 and 27.5; these people are considered overweight or moderate risk according to Asian-specific categories, but about half are considered normal weight according to general population categories. To our knowledge, ours is the first research study describing perceptions of weight and the health effects of weight in South Asian Americans, a population at high risk for diabetes and cardiovascular disease (15,16).
Our finding that South Asian Americans underestimate their weight status and weight-related health consequences is not surprising. These underestimations are common and increasingly prevalent among the general population of the United States (9). Among white populations, approximately one-third of overweight and 5% of obese people perceive their weight to be normal (10). Among Hispanic and African American populations, the magnitude of underestimation is even higher (10,17-19). Studies in the United Kingdom indicate that overweight South Asian women are more likely than white women to underestimate their weight status (20,21) and to equate a larger body size with health (22). Although our study did not compare South Asians with other racial/ethnic groups, the degree of underestimation of weight status may be greater among South Asians than among other groups.