Match the benefit with the method of obtaining food intake.

The diet history method is a detailed retrospective dietary assessment which obtains details of individual foods, and comprehensive information about foods eaten less regularly. It is used to describe usual food and / or nutrient intakes over months or a year. The outcomes measured by dietary history are described in Table D.2.21.

Nutrient intakes obtained by a dietary history are often compared to those obtained by a weighed diary for a purpose of validation. In a small subsample from the Survey in Europe in Nutrition and the Elderly Concerted Action (SENECA) study, for example, reported energy intakes were higher but less than energy expenditure measured by indirect calorimetry [7].

One study compared energy intakes obtained by weighed dietary records and diet histories to energy expenditure estimates obtained by doubly labelled water in children and adolescents. Although mean energy intakes were biased towards overestimation, the differences were small and the authors concluded that the energy intake obtained by a diet history was more representative of habitual intake than the weighed diet diary [4].

Table D.2.21 Dietary outcomes assessed by dietary history.

A dietary history is a retrospective structured interview method consisting of questions about habitual intake of foods from the core food groups (e.g. meat and alternatives, cereals, fruit and vegetables, dairy and ‘extras’) and dietary behaviours (e.g. skipping breakfast, dieting).

The interview technique can use open ended questions to determine foods and drinks consumed at each meal, followed by specification of amounts. This is followed by a ‘cross check’ to clarify information about usual intake in the past 3, 6, or 12 months, depending on the aims of the assessment. It can be combined with a 3-day record or a 24-hour recall.

Usual portion sizes are generally obtained in household measures and / or the use of photographic aids. The method necessitates a face-to-face interview, as it is difficult to adapt for telephone interview, self-completion or computer completion by the individual.

Depending on participants’ characteristics and an aim of dietary assessment, the interview may put weight on specific dietary items or behaviours. For example, if a target population is pregnant women, diet history should capture use of dietary supplements and an experience of ‘pica’ (food craving). If the research aim is to identify a common dietary habit of people admitted to a hospital during a heatwave or an infectious outbreak, specific food consumption in a specific period may be assessed retrospectively.

Dietary history is suitable when the assessment aims to capture detailed information about habitual food intake or food intake at a specific life stage or a specific time period. For example, a large international cohort study, the SENECA [7], recruited elderly adults and assessed their diet during one month preceding an interview.

Researchers may be interested in a diet during a specific period. Examples include a diet during pregnancy, diets of patients diagnosed with a foodborne illness, and diets of victims afflicted by a disaster. For those, a diet history method with a structured checklist is well suited to capture dietary exposure during a specific time period.

A few prospective cohorts have been using diet history methods including Coronary Artery Risk Development in Young Adults (CARDIA) in the United States and Kuopio Ischemic Heart Disease Risk Factor Study in Finland. Diet history requires trained interviewers, not to be self-administered, and remains unclear whether it would give more valid and reliable measures of dietary exposure than food frequency questionnaires. For a large-scale prospective study, diet history is not likely to be the primary choice.

Estimates of nutrient intakes follow a general procedure common with other dietary assessment tools. The following steps are undertaken to estimate nutrient intakes.

• Mixed meals, if recorded, should be converted to single food items as much as possible. Single food items are supposed to be matched with those in a food composition table.
• Convert a portion size to gram amounts or amounts in a standard unit (ml for liquids) of each dietary consumption. Frequency should also be standardised to consumption per day or per week.
• Match all foods and ingredients with items in a food composition table.
• Obtain nutrient intakes from each food, by calculating a product of an amount of each item consumed per day or per week and nutrients contents per amount of each item.
• Obtain nutrient intakes per day per individual by calculating a sum of intakes of the nutrient per day per individual. This calculation can be specific to intakes in breakfast or different settings in a day.

Key characteristics of dietary histories are described in Table D.2.22.

Strengths

• Individuals need not be literate
• Covers usual diet in detail so only one interview is necessary for the particular time period under consideration
• Details of individual foods are obtained
• Information is obtained about foods eaten less regularly
• Energy intake and most nutrients can be estimated reasonably accurately

Limitations

• The resulting data depend heavily on the skill of the interviewer
• Interview based method may result in observer bias
• The individual may not remember past food consumption and be subject to recall bias
• It may also be difficult for the individual to assess portion sizes of past meals
• The method is difficult for those with erratic eating habits such as shift workers
• Individual food coding is necessary - this is time consuming requiring trained staff and is consequently expensive

Table D.2.22 Characteristics of dietary histories.

Considerations relating to the use of dietary history for assessing diet in specific populations are described in Table D.2.23.

Table D.2.23 Suitability of diet assessment by dietary history in different populations.

Among all the dietary assessment methods, the dietary history relies most heavily on the skills of the interviewer, who should have knowledge of local foods, and possess good communication and interviewer skills these include a non-judgmental, non-directive, probing style of interviewing.

• Trained interviewer
• Checklist and materials to record responses
• Trained diet coders
• Nutrient database and analysis program

A method specific instrument library is being developed for this section. In the meantime, please refer to the overall instrument library page by clicking here to open in a new page.

The diet history method has been implemented in a face-to-face interview and with an open-ended format. Further development of this style has not been apparently sought for in the field of nutritional epidemiology. However, with advancement of technology, a remote face-to-face interview may be conceivable to implement the diet-history assessment.

References

1. Black AE, Prentice AM, Goldberg GR, Jebb SA, Bingham SA, Livingstone MB, et al. Measurements of total energy expenditure provide insights into the validity of dietary measurements of energy intake. J Am Diet Assoc. 1993;93(5):572-9.
2. Burke BS. The dietary history as a tool in research. J Am Diet Assoc. 1947;23:1041-6.
3. de Vries JH, de Groot LC, van Staveren WA. Dietary assessment in elderly people: experiences gained from studies in the Netherlands. Eur J Clin Nutr. 2009;63 Suppl 1:S69-74.
4. Livingstone MB, Prentice AM, Coward WA, Strain JJ, Black AE, Davies PS, et al. Validation of estimates of energy intake by weighed dietary record and diet history in children and adolescents. Am J Clin Nutr. 1992;56(1):29-35.
5. Rothenberg EM. Experience of dietary assessment and validation from three Swedish studies in the elderly. Eur J Clin Nutr. 2009;63 Suppl 1:S64-8.
6. Ruitishauser I, Black A. Measuring Food Intake. In: Gibney MJ, Vorster HH, Kok FJ, editors. Introduction to Human Nutrition. Oxford UK: The Nutrition Society, Blackwell Publishing; 2002.
7. van Staveren WA, de Groot LC, Haveman-Nies A. The SENECA study: potentials and problems in relating diet to survival over 10 years. Public Health Nutr. 2002;5(6a):901-5.