Validation of a Food Frequency Interview Schedule to Assess the Dietary Intake of the Population in Hyderabad City - A Cross-Sectional Study

The food frequency questionnaire (FFQ) is the preferred method to evaluate long-term usual dietary intake in population-based epidemiological studies because it is simple, easy to administer and requires minimal effort from the subjects. Therefore, we validated a food frequency interview schedule (FFIS) to estimate the dietary intakes of the urban population of Hyderabad city. Methods: A cross-sectional study was conducted among five socio-economic sections of Hyderabad. Areas for the survey were selected by cluster random sampling and households in each area were selected by simple random sampling. The FFIS was developed and validated against a 6-day 24-hour dietary recall (HDR) method. The instruments were administered to the participants six months apart to check for reproducibility. Statistical analyses for validation and reproducibility included correlation, regression analyses and paired t-test. Results: Means of intakes of foods measured by 24-HDR were significantly lower than those measured by FFIS for some foods at alpha levels of 0.05. Pearson's correlation (r) for the intakes by the two methods ranged from 0.12 to 0.85. Regression coefficients were significant for 12 food groups. Correlation coefficients for the two FFISs were between 0.31 (spices) and 0.81 (carbonated beverages) and showed good reproducibility. Intakes of conventional foods like cereals, pulses, vegetables etc. by FFIS correlated better with 24-HDR than the processed foods such as breakfast cereals and bakery items. Conclusion: The data suggests that the FFIS is a well-validated, reproducible tool for assessment of long term dietary habits of a specific population. However, its use for populations of other regions requires specific modifications.

Diet, nutrition & cancer--the Indian scenario.

Cancer continues to be a major health problem despite advances in medical technology for its diagnosis and treatment. Hence prevention strategies are needed to decrease the burden of the disease. Of all the environmental factors, dietary components appear to play an important role in the initiation/progression of the disease. Nutrients and non-nutrients in the diet can influence the carcinogenic process at various stages, from initiation to overt manifestation. The National Institute of Nutrition has conducted studies on several aspects of diet-cancer inter-relationships. These include studies on metabolic susceptibility, case-control approach to determine the risk factors and intervention studies to determine the role of nutrients and non-nutrient components on preneoplastic events. Extensive work has been carried out demonstrating the antimutagenic/anticarcinogenic potential of some commonly consumed spices and vegetables such as turmeric, mustard, green leafy and allium species of vegetables. Dietary intervention for cancer prevention is needed to control the disease besides avoiding risk factors such as smoking and alcoholism and exposure to genotoxicants. Public education and awareness about the beneficial effects of consuming a healthy diet including plenty of fresh vegetables and fruits with spices such as turmeric in adequate amounts to prevent cancer are required.