The authors conducted a dietary methodology study in 1984 in Finnish men aged 55-69 years in order to validate two dietary assessment instruments being used in the US-Finland Alpha-Tocopherol, Beta-Carotene Lung Cancer Prevention Trial. Twelve 2-day food records collected from 162 men over a 6-month period, including every day of the week, served as the reference measure. This report focuses on three important questions for investigating diet and disease relations: 1) How many days are necessary to classify "usual" intake? 2) Is there loss as a result of using consecutive days? 3) Which days are necessary for assessment and classification of "usual" diet? A repeated-measures regression model was used to estimate the variance components and the effects of consecutive days, weekday (weekday vs. weekend), and season. Correlations between the averages of different numbers of days of food records and "true" usual intake were examined along with the resulting attenuations in relative risk. Results suggest that 7-14 days are required to adequately classify most individuals into categories of intake for most nutrients and some foods. There appears to be some loss of information from using consecutive days rather than days further apart. Weekday/weekend differences in mean intakes are slight, and the rank ordering of individuals appears to be preserved. A moderate seasonal effect is shown for classification of fruits, but only a slight one is seen for micronutrients and berries. Implications for the design of epidemiologic and validation studies are discussed.
The purpose of this study is to provide information on the current sources of dietary sodium in the Canadian food supply to provide a baseline to measure against the effectiveness of strategies to reduce salt consumption. Such strategies are being developed by a Health Canada-led multistakeholder Working Group. Data from the 2004 Canadian Community Health Survey (CCHS) 2.2, Nutrition, were used to determine the leading food group contributors of sodium in the diet. The total sample size was more than 35,000 respondents. The results from this study were reported for 4 age and sex groups, namely, youths aged 1 to 8 years, youths aged 9 to 18 years, males aged 19 years and older, and females aged 19 years and older. Average daily intakes of sodium for these groups were 2388 mg, 3412 mg, 3587 mg, and 2684 mg, respectively. In all cases these intakes exceeded the tolerable upper intake level (UL) established by the Institute of Medicine, as well as targets set by the governments of the United Kingdom and the United States and the World Health Organization. The contribution of sodium to the food supply by the top 40 food groups is presented for each of the age and sex groups. The key food group contributors of sodium are breads (13.88%), processed meats (8.90%), and pasta dishes (5.67%). Although breads are found to be major contributors of sodium, this is mainly because of the large consumption, rather than a high concentration of sodium. Higher-sodium foods, such as processed meats, are eaten in smaller quantities but, because of their sodium density, contribute significant amounts of sodium to the diet of Canadians. Some very high sodium foods, such as frozen dinners, are eaten by only a small proportion of the population, but for those consuming these, the sodium could contribute a significant proportion of the UL just from a single meal.
[Development of a method of studying actual nutrition according to analysis of the frequency of consumption of food products: creation of a questionnaire and general evaluation of the reliability of the method].
The method of actual feeding evaluation on frequency of food-stuffs consumption was developed. The method of 24-hour reproduction of a feed and the method of consumed food registration in a diary by testing person himself. The main results of study testified to reliability of data, received by a developed method.
The distribution of acrylamide in food items frequently consumed by Canadian adolescents was determined along with estimates of their contribution to the overall dietary intake of acrylamide. A total of 196 non-smoking adolescents (10-17 years old) were recruited in Montreal Island population, Canada. Participants were invited to fill out a 2-day food diary and a food frequency questionnaire over the last month. 146 samples of foods most frequently consumed by participants were analyzed for acrylamide contents. The highest acrylamide contents were measured in deep-fried french fries and potato chips (mean ± SD: 1053 ± 657 and 524 ± 276 ng/g respectively). On the basis of the 2-day food diary, median total daily intake of acrylamide was estimated at 0.29 µg/kg bw/d, as compared to 0.17 µg/kg bw/d on the basis of the food frequency questionnaire. These values are similar to those reported in comparable populations. Deep-fried french fries consumption contributed the most to daily acrylamide intake (50%) followed by potato chips (10%), oven-baked french fries (8%) and breakfast cereals (8%). Margins of exposure based on genotoxic benchmark dose limits were estimated to be low (˜
The purpose of this study was to assess the dietary glycemic index (GI) and glycemic load (GL) of adolescents, based on a Web-based 24-h recall, and to investigate dietary predictors of GI and GL. In addition, the relationship between GI and GL and weight status was examined. A Web-based 24-h recall was completed by 4936 adolescents, aged 9-17 years; macronutrient and food group intakes were assessed using the ESHA Food Processor, the Canadian Nutrient File, and Canada's Food Guide. Dietary GI and GL were calculated based on published GI values for foods. Students provided self-reported height and mass. Multiple regression models assessed the ability of food group choices and food behaviours to predict GI and GL. Mean GI was 55 for girls and 56 for boys. Mean GL was 128 for girls and 168 for boys. Food group choices explained 26% of the variation in GI (p
Under-reporting of food consumption is a recurrent challenge for nutrition surveys. Past research suggests that under-reporting tends to be most pronounced among overweight and obese people.
Data from 16,190 respondents to the 2004 Canadian Community Health Survey (CCHS 2.2)-Nutrition were used to estimate underreporting of food intake for the population aged 12 or older in the 10 provinces. Multiple linear regression models were used to assess the impact of different characteristics on underreporting.
Average under-reporting of energy intake was estimated at 10%. Under-reporting was greater among people who were overweight or obese, those who were physically active, adults compared with teenagers, and women compared with men.
Under-reporting of energy intake is not random and varies by key health determinants. Awareness of the characteristics associated with under-reporting is important for users of nutrition data from the CCHS 2.2.
BACKGROUND: Nutritional epidemiology relies largely on dietary assessment methods for the estimation of the "exposure' variables which may be related to disease risk. METHODS: This paper describes a methodological study conducted in Malm?, Sweden, to compare nutrient intake--estimated by two alternative dietary assessment methods--with a reference method consisting of 18 days of weighed food records. The two candidate methods were an extensive food frequency questionnaire with portion size to be estimated from a booklet of 120 sets of photos (method A) and a method involving the combination of a shorter questionnaire and a two-week food record (method B). RESULTS: In absolute values, both methods overestimated nutrient intake by 20-40%, with method B closer to the reference for most nutrients. Both crude and energy-adjusted correlations between A-reference and B-reference were of the order of 0.50-0.60 for energy, energy-providing nutrients and most vitamins and minerals. Correlations were in the same range for most of the 14 fatty acids considered in the analyses. Protein intake, estimated from the analyses of urinary nitrogen on 6-8 repeated 24-hour urine collections per subject, was almost identical to the reference method values. Correlation between nitrogen-derived values and dietary measurement was 0.75. CONCLUSIONS: Overall, the study indicated that both methods A and B had good ranking validity compared to the reference and that in most cases the combined method (B) performed slightly better than the extensive food frequency method (A).
Foods to be included in a Danish self-administered semiquantitative food frequency questionnaire were identified from food tables developed, together with data collected, for the survey 'Dietary habits in Denmark, 1985'. The questionnaire was to be used in a prospective study on diet, cancer and health, and the aim was to rank individuals with regard to intake of 19 different nutrients considered of prime importance in human carcinogenesis. The questionnaire for the dietary survey included 247 foods and recipes. From stepwise multiple regression analyses with the intake of each of the 19 nutrients as the dependent variable and the intake of the 247 foods and recipes as independent variables, the foods in the models explaining 90% of the between-person variability were considered for the final questionnaire. All relevant analyses were performed for the study group as a whole, for men and women separately, and in each gender for subgroups of energy intake. Taken together, the models explaining 90% of the between-person variability identified a total of 74 foods or recipes, which were important predictors of the intake of one or more of the nutrients considered. A few foods were excluded and a few foods were added to the final questionnaire based on common biological background information, and on information on foods providing important amounts of given nutrients, but which failed to contribute to regression analyses. The 92 foods and recipes, which were included in the final questionnaire provided altogether 81% of the average total supply of the nutrients.(ABSTRACT TRUNCATED AT 250 WORDS)
Mild, growth-limiting zinc deficiency might be prevalent in otherwise healthy infants according to recent studies. We examined zinc intake and status in 91 healthy term infants from birth to 12 months, as part of the Copenhagen Cohort Study on Infant Nutrition and Growth. Zinc intake was recorded monthly and the amount of zinc absorbed was estimated. These estimates were below recently published FAO/WHO/IAEA values for basal requirements in 68%, 62% and 14% of the infants at 2, 4 and 9 months of age, respectively. Serum zinc decreased significantly (p