Designing a Mixed-initiative Recipe Recommender App for Vegan and Vegetarian Sub-groups

Iron is present in plant and animal-derived foods but the fractional absorption of iron from plant foods (that is the percent of iron absorbed from a consumed quantity) is often low (approx 10%) compared to iron from animal sources 25%-30%. It is therefore more challenging for vegans and vegetarians to achieve the Reference Nutrient Intake (RNI) for iron (8.7 mg/day for men over 18 and women over 50, 14.8 mg/day for women aged 18-50), and they are likely to absorb less of that iron and therefore are more likely to become iron depleted.

Plants do not synthesise vitamin B12 and unless fortified, plant-derived foods and beverages do not contain any vitamin B12. the RNI for vitamin B12 in the UK is 1.5 µg/day, therefore it is crucial that vegans and vegetarians take B12 supplements if they don't consume B12-fortified foods or find other ways of incorporating this vitamin into their diets.

Over a period of 17 weeks, participants will be asked to consume plants from the unit by following the recipes recommended by the app. The participants will then observe changes in their iron and vitamin B12 levels by following up with their GP and report the outcomes back to the researchers at three points during the study (week 0, week 6, and week 17). In addition, the participants will evaluate the usability of the app and the recipes recommended by the app.