Differences in consumption of food items between obese and normal-weight people in India.

Background. There is a rising prevalence of obesity in India, and diet may be a major determinant of this. We aimed to assess differences in types and quantities of food items consumed by obese and normal-weight people in India. Methods. Cross-sectional data of 7067 factory workers and their families were used from the Indian Migration Study, conducted in four cities across northern, central and southern India. Food frequency questionnaire data were used to compare the quantities of consumption of 184 food items between 287 obese (body mass index >30 kg/m2) and 1871 normalweight (body mass index 18.50–22.99 kg/m2) individuals, using t tests and ANCOVAs. Individuals with diabetes, hypertension and cardio-vascular disease were excluded. SPSS 16.0 was used for analysis. Results. After adjusting for age, sex, location and socioeconomic status, obese individuals were found to eat significantly larger quantities of 11 food items compared with normalweight individuals. These included phulkas, chapatis/parathas/ naan, plain dosa, mutton/chicken pulao/biryani, chicken fried/ grilled, rasam, mixed vegetable sagu, vegetable raitha, honey, beetroot and bottlegourd (p<0.01). Consumption of plain milk was higher among normal-weight than among obese individuals (p<0.05). Consumption of some of these food items was also found to increase by socioeconomic status, decrease by age, and be higher among men relative to women. Conclusion. Obese individuals were found to consume larger quantities of certain food items compared with normal-weight individuals. Interventions should aim at limiting overall food consumption among obese individuals.

Measuring Obesity among School-aged Youth in India: A Comparison of Three Growth References.

Objective: To compare three growth references that can be used to assess the weight status of school-aged youth living in India, with a particular focus on identifying overweight and obese youth. Study Design: Cross-sectional study. Kappa scores were used to measure agreement between growth references. Regression models were used to test for differences in weight status by grade level, gender, and school type, using each growth reference. Setting: Private (n=4) and Government schools (n=4) in Delhi, India. Participants: Students (n=1818) in eighth and tenth grade attending the schools. Main outcome measures: Weight status was derived using age- and gender-specific cut-points provided by: (a) a national growth reference specific to India; (b) an international reference recommended by the International Obesity Task Force (IOTF); and (c) a new international reference recommended by the World Health Organization (WHO). Results: The IOTF reference consistently classified participants in a lower weight status category, compared with the national reference (κ=0.57) and the WHO reference (κ=0.69). The agreement between the WHO and the national references was higher (κ=0.84). Conclusions: To date, all published studies of childhood obesity in India have used the IOTF reference, the national reference, or an old WHO reference to measure weight status among school-going youth. The new WHO reference may be a better choice. Compared to the IOTF reference, it does not appear to underestimate obesity and can still be used to compare trends, globally.

Microsatellite diversity among the primitive tribes of India.

The present study was undertaken to determine the extent of diversity at 12 microsatellite short tandem repeat (STR) loci in seven primitive tribal populations of India with diverse linguistic and geographic backgrounds. DNA samples of 160 unrelated individuals were analyzed for 12 STR loci by multiplex polymerase chain reaction (PCR). Gene diversity analysis suggested that the average heterozygosity was uniformly high ( >0.7) in these groups and varied from 0.705 to 0.794. The Hardy-Weinberg equilibrium analysis revealed that these populations were in genetic equilibrium at almost all the loci. The overall GST value was high (GST = 0.051; range between 0.026 and 0.098 among the loci), reflecting the degree of differentiation/heterogeneity of seven populations studied for these loci. The cluster analysis and multidimensional scaling of genetic distances reveal two broad clusters of populations, besides Moolu Kurumba maintaining their distinct genetic identity vis-à-vis other populations. The genetic affinity for the three tribes of the Indo-European family could be explained based on geography and Language but not for the four Dravidian tribes as reflected by the NJT and MDS plots. For the overall data, the insignificant MANTEL correlations between genetic, linguistic and geographic distances suggest that the genetic variation among these tribes is not patterned along geographic and/or linguistic lines.

Present status of understanding on the G6PD deficiency and natural selection.

G6PD deficiency is a common hemolytic genetic disorder, particularly in the areas endemic to malaria. Individuals are generally asymptomatic and hemolytic anemia occurs when some anti-malarial drugs or other oxidizing chemicals are administered. It has been proposed that G6PD deficiency provides protection against malaria. Maintaining of G6PD deficient alleles at polymorphic proportions is complicated because of the X-linked nature of G6PD deficiency. A comprehensive review of the literature on the hypothesis of malarial protection and the nature of the selection is being presented. Most of the epidemiological, in vitro and in vivo studies report selection for G6PD deficiency. Analysis of the G6PD gene also reveals that G6PD-deficient alleles show some signatures of selection. However, the question of how this polymorphism is being maintained remains unresolved because the selection/fitness coefficients for the different genotypes in the two sexes have not been established. Prevalence of G6PD deficiency in Indian caste and tribal populations and the different variants reported has also been reviewed.