JMIR Publications

ABSTRACT

Background:

A healthy diet throughout the life-course improve health and reduce the risk of disease. There is a need for new knowledge of the relation between diet and health, but existing methods to collect information on food and nutrient intake have their limitations. Evaluations of new tools to assess dietary intake is needed, especially in old people, where the introduction of new technology might impose challenges.

Objective:

We aimed to examine the usability of a new web-based dietary assessment tool in older adult women and men.

Methods:

A total of 60 women and men (participation 83%, 57% women) aged 60-74 years recruited by convenience- and snowball sampling completed a 24-hour online dietary recall using the newly developed Norwegian version of myfood24®. Total energy- and nutrient intakes were calculated in myfood24®, primarily based on the Norwegian Food Composition Table. No guidance or support were given to complete the recall. Usability was assessed by the system usability scale (SUS) questionnaire, where a SUS score ≥68 is considered satisfactory. We examined the response to SUS single items and mean SUS score with standard deviations (SD) in groups of sex, age, educational level and device used to complete the recall (smartphone, tablet, or computer).

Results:

Mean total energy intake was 5815 (SD 3093) kilojoules. A total of 14% had an energy intake <2100 kilojoules (i.e., 500 kilocalories), and none >16800 kilojoules (i.e., 4000 kilocalories), respectively. Mean energy percentages from carbohydrates, fat, protein, alcohol and fibre were within the national recommendations. Mean SUS was 55.5 (SD 18.6), and 27% had SUS scores above the satisfactory product cut-off. Higher SUS scores were associated with younger age and lower education, but not with the type of device used.

Conclusions:

We found the overall usability of a new web-based dietary assessment tool to be below satisfactory according to standard usability criteria in a sample of 60-74 year-old Norwegians. The observed total energy intakes suggest that several of the participants underreported their intake during the completion of the dietary recall. Implementing online dietary assessment tools in older adults is feasible, but guidance and support might be needed to ensure valid completion.