Diet checklists

The following outcomes can be assessed using a dietary checklist:

• Frequency, amount, or other attributes of dietary consumption in a brief list of dietary items including foods and supplements
• Adherence to a certain dietary intervention or a special dietary pattern
• Likelihood of being exposed to food pathogens
• Dietary habits or consumption of specific foods not likely to be captured in other methods
• Group-level dietary consumption or exposure

A checklist that is designed for a specific purpose tends to be less detailed in contrast to other methods. The outcomes measured by a dietary checklist depend upon the design. Any outcomes can be assessed if targeted as indicated in Table D.2.17. For example:

• In a clinical setting pertaining anaemia, a checklist capturing major food sources and supplements of iron and vitamin B12 may be sufficient and allow calculation of amount of the specific nutrients
• In research on an effect of providing breakfast to those who tend to skip breakfast on health outcomes, a checklist to assess adherence to the intervention and related habits may be sufficient
• In research on foodborne illness, a checklist can be about food consumption in a very specific occasion (e.g. “the wedding ceremony at Hotel X on 22 August 2015”)

A checklist can be used for an assessment of group-level exposure to certain foods in a certain environment. For example:

• Vending machines for snacks or soft drinks or plain water in a school
• Types of foods sold in a restraint or deli, such as raw meats and foods that can cause allergic reactions
• Marketing policy and practice of a local supermarket or stores in a school

A dietary checklist can be either self-administered or interview-administered. A dietary checklist includes elements of a food frequency questionnaire (as it is based on a pre-printed food list). Respondents examine a list of foods, supplements, or other dietary items and cross-tabulate with attributes such as specified serving size (e.g. slices, teaspoons) or frequency of consumption or both, ticking the box appropriately. An example of a dietary checklist is displayed in Figure D.2.6.

An assessor can administer a checklist to a respondent through face-to-face or phone interview, alternatively it may be preferable or required to send a checklist to a respondent through post or email and request him/her to complete it and send it back.

Use of blank space for each item and for an entire list is helpful to encourage a respondent to provide any information such as specific dietary patterns (e.g. vegan, a habit related to a religion, being on a weight-loss diet), alternative serving sizes for certain foods, and his/her key foods not listed. Sub-sections for a specific setting, e.g. ‘eating out and takeaway’ section, may help, depending on aims of a checklist.

Screening individuals for a specific dietary problem or intervention: For example:

• to assess adherence to specific dietary patterns, for example the Mediterranean diet [7, 8]
• to identify needs for education about unusual dieting
• to identify dietary behaviours or experiences associated wtih food poisoning, allergy, or dieting
• to implement an targeted intervention to reduce consumption of sugar-sweetened beverages
• to identify needs to encourage dietary consumption with family members
• to assess adherence to an intervention

Categorical or continuous answers to each item, such as

• Yes or No for consumption of certain foods, preference of foods or related behaviours, experiences of having meals in a dietary setting (e.g. a specific restaurant).
• Frequency of consumption or a dietary practice over a certain period of time (e.g. frequency of snacking)

Answers can be combined for the purpose of a checklist

• to estimate consumption of a food group
• to assess an overall degree of adherence to a certain intervention
• to estimate nutrient intakes from selected food items and supplements

Key characteristics of dietary checklists are described in Table D.2.18.

Strengths

• Flexible to design a checklist and assess a targeted dietary habit or consumption. Dietary assessment for foodborne illness often has a checklist to reflect this strength, to assess dietary exposure in a very specific occasion [11].
• Low participant burden. For example, in the Low Income Diet and Nutrition Survey, respondents preferred the food checklist over a 24-hour recall and weighed food diary [6].

Limitations

• Not useful to capture detailed dietary habits to answer many different clinical or epidemiological questions
• Dependent upon an implementation, there is the risk of recall bias
• Dependent upon an implementation, a respondent may need to be literate, numerate, or both. The LIDMS study (Figure D.2.6) found the following issues to be most common: ticking the boxes (18%), understanding the portion sizes (18%), understanding what was required (16%), finding the food on the list including ethnic minority foods (15%), recording food eaten outside the home (15%) [6].

Considerations relating to the use of dietary checklists for assessing diet in specific populations are described in Table D.2.19.

• Trained fieldworkers can go through a dietary checklist, probing for missing items, during and at the end of the recording period
• The food list must be designed for a specific purpose of research

• Trained fieldworkers to instruct respondents on how to complete the dietary checklist, monitor completion and review the outputs at the end of the assessment
• Depending on a design and aims, the following items may also be required:
• Additional questionnaire to aid interpretation
• Instructions on completion and return of the checklist
• 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.

As a checklist can be flexible and tailored for a specific research aim, developing a checklist is often the last step in designing a study after all variables of interest have been identified. As a general rule in a questionnaire method, following attributes should be confirmed.

• Simplicity/clarity
• Relevance to research aims
• Completeness to assess target variables

Points to consider when drafting questions (adapted from [11]):

• Clarify the aim of a checklist
• Keep wording informal, conversational and simple
• Avoid jargon and sophisticated language
• Avoid long questions (but vary question length)
• Keep questions appropriate to educational, social and cultural background of the respondents
• Avoid leading questions linked to social or personal desirability
• Avoid negative questions, questions beginning with “Why”, hypothetical questions
• Limit each question to a single subject
• Pay attention to sensitive issues
• Check the adequacy of the list of responses to closed-end questions and needs for open-ended questions

In a phase of finalising a checklist, mock implementation is essential to confirm time to complete and ease of filling the checklist.