Though web technologies have generated several success stories, designing and evaluating such complex systems is very challenging for the following reasons:
First, increasing complexity becomes a design challenge. Dietary intake choices are a complex matter, thus, more and more features need to be included in a single system to support multiple intervention strategies and numerous design decisions are needed to build a well-integrated system. In addition, since the target population could be people with low computer literacy (e.g., older adults and young children), the design space for a system could be restricted. In other words, if one would like to employ innovative web techniques (e.g., novel interaction and/or visualization technique), an inappropriate level of novelty may become a barrier for some target users, rather than benefiting them.