The prevalence of obesity nationally, combined with the ever-increasing pressure to control health care use and costs, make it imperative for health care organizations to implement more effective, efficient, and proactive tools for health behavior change and decision-making. Web-based weight management programs have the potential to reach millions of individuals at a relatively low cost. Questions remain, however, about the efficacy of such programs in accurately informing the user and facilitating health-related behavior change through evidence-based methods. While a large number of weight management programs are now offered through the Web, most of these sites contain information of questionable value and generally fail to take advantage of existing research or established theoretical models. In one of the first randomized trials conducted in this area, the researcher recently found poor outcomes of a commercial Internet-based diet program (eDiets).

Web-based programs using trained on-line counselors, however, have shown successful weight-loss outcomes. These studies signify the Internet as a viable media channel for weight-loss programming. The reach of such programming, however, is limited to the number of available weight management counselors. One of the advantages of trained counselors is their ability to assess specific needs and interests of the client and tailor feedback in a manner that focuses content to these specific needs and interests, ideally providing just the right help at the right time, and removes extraneous content. The content and sequencing of the assessment and feedback by the human counselor are hopefully based on empirically- and theoretically-based understanding of the problem. Software programs attempting to replicate and standardize this interactive assessment and tailored feedback process are termed "expert systems". Digitally tailored print versions of expert systems have been found to be successful in reducing dietary fat intake and in increasing physical activity. While digitally tailored print materials can be distributed at a low-cost relative to most existing approaches to weight management, the Internet can distribute these materials at a far lower cost. Moreover, the Internet offers significant advantages over print-based tailored materials in the interactivity and vividness of data collection and feedback.