The aim of this study was to define the type of nutritional interactive computer interface suitable for use by elderly people.

Three experimental interactive interfaces designated to assess nutrient intake were built, backed by hidden computer tracking programs. The 3 websites were: 1. An "ABC list" in which food items were presented in alphabetical order, 2. A "Food Groups" website and 3. A "Structured" website based on recall dietary protocol. Two groups of experienced Internet users participated: older adults (73.75±7.3 years) and adult (55.32±4.7 years) (n=20 for each group, equal number of men and women). The participants were asked to insert the content of their meal in the three experimental websites. Parameters for scoring were: time for task completion (total and per food item), number and types of operations, errors, satisfaction and personal preference.

Time per food item selection was significantly longer in older participants compared to adults participants (p<0.05). A positive correlation was demonstrated between average time food item selection and age, and a negative correlation with internet experience, in all experimental websites. The shortest total time period for task completion was measured in the "Food Groups" website in both age groups. The total number of operations (clicks) and average operations per food item were significantly lower at the "Food Groups" website in both two age groups.

Our results suggest that the most appropriate nutritional interface for older adults and adult people, in terms of time and efficiency, is the "Food Groups" website. The worst performance was obtained at the "Structured" website by older adults and adult people.