During a 24-hour diet interview, participants are interviewed on food and drink intake the previous day. The amount eaten and drunk is listed in known units, household measurements or in terms of pictures of foodstuffs in different portion sizes. The method provides average data for intake of energy, nutrients and foodstuffs among groups of the population, and dispersal. The interviews also yield data on meal patterns and places for eating. An EU-funded project (EFCOSUM) has recommended 24-hour diet interviews as the best method for procuring data that is comparable in Europe1. This method has long been used in the large US National Health and Nutrition Examination Survey NHANES2. Finland, Germany, the Netherlands, Belgium and Spain are other examples of countries that have used 24-hour diet interviews for national diet surveys.
A frequency questionnaire without volumes has been used in the USA in addition to 24-hour diet interviews to provide supplementary information about the participants' regular intake of food and drink3, 4. Instead of using the frequency questionnaire to estimate the intake of nutrients and groups of foodstuffs, the information from the frequency questionnaire has been used as co-variants in a statistical model to improve the estimates from the diet interviews. The English ”Food Propensity Questionnaire” is called the "Matvaretendensskjema" in Norwegian.
24-hour interviews were used during the projects: Norkost 3 and EFCOVAL.
1. Brussaard JH, Lowik MR, Steingrimsdottir L, Moller A, Kearney J, De HS, Becker W. A European food consumption survey method--conclusions and recommendations. Eur J Clin Nutr 2002;56 Suppl 2:S89-S94.
2. Raper N, Perloff B, Ingwersen L, Steinfeldt L, Anand J. An overview of USDA's Dietary Intake Data System. Journal of Food Composition and Analysis 2004;17:545-555.
3. Tooze JA, Midthune D, Dodd KW, Freedman LS, Krebs-Smith SM, Subar AF, Guenther PM, Carroll RJ, Kipnis V. A new statistical method for estimating the usual intake of episodically consumed foods with application to their distribution. J Am Diet Assoc 2006;106:1575-1587.
4. Subar AF, Dodd KW, Guenther PM, Kipnis V, Midthune D, McDowell M, Tooze JA, Freedman LS, Krebs-Smith SM. The food propensity questionnaire: concept, development, and validation for use as a covariate in a model to estimate usual food intake. J Am Diet Assoc 2006;106:1556-1563.
The Precoded food diary used in UNGKOST-2000
The precoded food diary was created in 1999 and 2000 for use as a tool in UNGKOST-2000.
The diary consists of 20 pages of lists of foodstuffs/drinks. The lists are divided into large groups of foodstuffs, so that drinks, bread, dinners, etc. are listed separately. The most common food/drinks are listed, and there are empty lines in each group of foodstuff where one can enter food that is not listed in the diary.
A unit (e.g. drinks are listed in terms of number of glasses, bread as number of slices) is given for each foodstuff/drink. The diary is completed by the participants writing how much of the foodstuffs (number of units) they have eaten during each period of time.
The day is divided into five blocks of time (e.g. from 06:00–10:00, from 10:00–14:00).
The diary contains components of diet registration and 24-hour interviews. During the day, most UNGKOST participants recorded what they ate, and every evening of the registration period, they entered this information into the precoded food diary.
The UNGKOST participants reported that the precoded food diary and picture book are easy to use, and are suitable for the age group. The diary has been validated against ActiReg® in two groups of year 8s.
The diary has also been used among children and youths with type I diabetes.
The diary was validated among a group of adults (unpublished data). This is also the case in current studies of adults.
Picture book with portion sizes used for UNGKOST-2000
The diary also comes with a picture book to help set portion sizes.
The picture book contains pictures of different glass sizes and bread slice thicknesses. There are also pictures of four different portion sizes for 13 foodstuffs/dishes, with the smallest size being A, and the largest size being D. The 13 foodstuffs/dishes are: butter/margarine on bread, cornflakes, porridge, spaghetti/pasta, mashed potatoes, chips, mixed vegetables, salad, bolognaise sauce, pizza sliced as triangles or squares, fish, and ice cream.
The picture book was created for UNGKOST-2000, and is used with the precoded food diary.
The picture book was evaluated in a group with an age variation of 9–84 years.
It will also be possible to use the picture book alone to determine portions or with some other form of registration than the precoded food diary. We have also created a more exhaustive picture book for Norkost.
Lillegaard ITL, Øverby NC, Andersen LF. Can children and adolescents use photographs of food to estimate portion sizes? Eur J Clin Nutr.2005 Apr;59(4):611-7.
There are no error-free methods for measuring food intake in diet surveys. This is why it is important to develop objective goals for intake on both the foodstuff and nutrient level (biomarkers). Biomarkers can be used to validate traditional methods, as well as alone to measure intake or together with traditional methods.
At present only a few biomarkers are considered valid:
a. The doubly labelled water (DLW) method, which in the event of an energy balance can be used to provide information about energy intake.
b. Nitrogen in urine that can be used as a marker of protein intake.
c. The fatty acids pattern in blood and fatty tissue as a marker for intake of particularly essential fatty acids.
For years the diet group has applied biomarkers to validate the diet survey methods used by the group. The biomarkers used are the DLW method, the fatty acid pattern in serum phospholipids, total serum and fatty tissue, the serum concentration of carotenoids and tocopherols (see reference 1-3).
In 2000 we started a research project to find biomarkers that reflect the 'true' intake of fruit and vegetables. A controlled eating experiment with a cross-over design was conducted in the autumn of 2001. 39 out of 40 participants completed the controlled diet experiment. The experiment diets were controlled in terms of intake of fruit and vegetables, and their preparation. The two diets consumed contained 2 and 5 portions, respectively, of fruit and vegetables per day. 24-hour urine was collected, and blood tests were taken from the participants four times during the experiment period (before and after each intervention period). Six carotenoids were analyzed in serum (lutein, zeaxanthin, lycopene, b-cryptoxhantin, b-carotene, a-carotene), and 8 flavoinoids in 24-hour urine.
Eating experiment project group: Lene Frost Andersen, Asgeir Brevik, Christian Drevon, Kerstin Trygg
Collaboration with the eating experiment: Rune Blomhoff, Institute for Nutritional Research, University of Oslo. Salka Nilsen, Food Administration Directorate, Denmark.
1. Andersen LF, Solvoll K, Drevon CA (1996). Very long-chain n-3 fatty acids as biomarker for intake of fish and n-3 fatty acid concentrates. Am J Clin Nutr. 64, 305-311
2. Andersen LF, Solvoll K, Johansson L, Salminen I, Aro A, Drevon CA. (1999). Evaluation of a food frequency questionnaire with weighed records, fatty acids and alpha-tocopherol in adipose tissue and serum. Am J Epidemiol. 150, 75-87
3. Andersen LF, Tomten H, Haggarty P, Løvø A, Hustvedt BE. Validation of energy intake estimated from a food frequency questionnaire: A doubly labelled water study. Eur J Clin Nutr.