1. The correlation of estimated dietary protein with estimates based on nitrogen excretion was 0.56 (winter) and 0. 48 (summer). Methods Data was collected over 1 week periods in winter (January-March) and summer (June- September), 2000. A 24 hr recall covered the first day of participation (D1) and subjects were instructed to record on the other days (checked at visits on days 3, 4, 6 and 8. 24hr urine collections, monitored for completeness by the administration of 3 tablets of 80mg of PABA, were made on D1 and D7. Only apparently complete collections were used in these analyses (n = 107 in winter and 93 in summer). Blood was collected on the morning of D8. Individuals with a ratio of estimated energy consumption (by 7DDD) to estimated BMR (EI/BMR) less than 1.35 were classified as energy under-reporters (Goldberg cut-point). The open ended estimated 7DDD contained written instructions to record portion sizes, pages to record foods eaten during seven day time period (before breakfast, breakfast, midmorning, lunch, early evening ) for each of seven days. An album was provided including color photographs of different foods and dishes, each set of photographs depicted 3 different portion sizes of a common food item to aid estimation of portion weight. The dietary database system was developed by the National Institute of Hygiene (Sofia) and based In Microsoft Access. It incorporated information on 904 simple or constituent foods (taken here to include drinks). 397 composite foods defined by standard (national) recipes. Food information was adjusted in the light of responses regarding methods of food preparation. During data entry a further 2013 composite foods were defined based on local recipes (1089 in winter and a further 924 in summer). To analyse intakes of foods and of nutrients, the system decomposes composite foods back to their constituent foods. The record for each food in the database incorporates estimates of losses during preparation and cooking and the proportion waste. The associations between the biomarkers and the reported intakes were assessed separately for each of the intake- biomarker pairs. The accepted level of significance was set at p =0.05. All statistical analyses were performed using SPSS 11.0 Results The mean EI/BMR ratio was 1.43 ± 0.40 in winter and 1.27 ± 0.39 in summer and was higher for males. 48 % of subjects in winter and 63 % in summer were classified as energy under-reporters using estimated EI: estimated BMR < 1.35. 361 Validation of a 7 day diet diary using urinary and blood biomarkers: Varna Diet and Stroke Study biomarkers: Varna Diet and Stroke Study Krassimira Stoeva 1, Klara Dokova 1, John Powles 2, Veselka Duleva 3, Stefka Petrova 3, Nevijana Feschieva 1, Shirley Runswick 4, Maria O'Connell 5, Elliot Berry 6, Sheila Bingham 4 (1) Dept of Social Medicine, Medical University, Varna, Bulgaria, (2) Dept of Public Health and Primary Care, University of Cambridge (3) National Centre for Hygiene, Medical Ecology and Nutrition, Sofia (4) MRC Dunn Human Nutrition Unit, Cambridge (5) MRC Human Nutrition Research, Cambridge (6) Department of Medicine, Hadassah Hebrew University Hospital, Jerusalem Funding source RURAL AREA URBAN AREA The village of Grozdevo is some 60 km to the south-west of Varna. Population about - 2600 people. Primorski district is is one of the biggest living areas in Varna including approximately 28% of the urban population (about 86 000 inhabitants) Subjects Subjects eligible for participation are in the age group 45 to 74 years, devided in 3 age- and sex-specific strata, residents of the study areas - Urban (District Primorski) and Rural (Grozdevo village). 188 (97 urban and 91 rural) subjects volunteered to participate in the validation study from them 160 (78 urban and 82 rural) continued their participation in the summer cycle of the study. Fieldwork Study schedule Urine collections Blood collections Energy under-recording The 7-day diet diary An interviewer explaining to a study volunteer how to use the dietary album. Energy under-recording Statistical analysis Nutrient database Under-reporting was associated with BMI (80% had BMI’s > 25). 7 day diet diary in comparison with biomarkers y winter = 50.7 + 0.4 x r = 0.56 y summer = 52.6 + 0.3 x r = 0.48 Correlations between estimated Na and K consumption and urinary excretion lay in the range 0.42 (Na, winter) to 0.31 (K, summer). For Vitamin C, correlations were lower (as expected) when intakes were high (winter, r = 0.43; summer, r = 0.16). y winter = 3385.9 + 0.7x r = 0.42 y summer = 3270 + 0.7x r = 0.44 Dietary vs. Urinary nitrogen Dietary vs. Urinary Sodium and Potassium y winter = 33.1 + 0.2x r = 0.43 y summer = 64.4 + 0.02 r = 0.16 Conclusions Use of a 7DDD proved feasible (though challenging and laborious) in urban and rural areas in a country classified by the World Bank as ‘moderately indebted lower middle income’. Assuming a true group mean Physical Activity Level (energy expenditure/BMR) ≥ 1.55, energy under-reporting was ≥ 8% in winter and ≥ 18% in summer. The 7 DDD appeared able to classify individuals by their intakes of protein, sodium, potassium and vitamin C to a comparable extent to its performance in western populations. Validity in Bulgaria may be aided by the much smaller variety of foods consumed. The results for dietary constituents of special interest for future studies of stroke – sodium, potassium and vitamin C (as a biomarker for fruits and vegetables) – were satisfactory. y winter = 33.1 + 0.2x r = 0.43 y summer = 64.4 + 0.02 r = 0.31 Introduction Dietary correlates of high vascular risk in Bulgaria remain largely uninvestigated. Epidemiological study of dietary exposures requires a dietary assessment instrument with known levels of validity for the exposures of interest in the population of interest. Aim To assess the validity of estimates of dietary intakes from a 7-day diet diary (7DDD) by comparing them with:  estimated energy requirements;  urinary nitrogen (for estimating protein intake), sodium and potassium excretion;  plasma vitamin C concentration. Web address: http://www.phpc.cam.ac.uk/varna/stroke/index.html