Matching, which pertains to the first part of our model, has long been a key aspect of medical treatment. Chapter 5 reviews several schemes for matching in the obesity field, all of which we found useful although limited for our purposes. We approached the matching of individuals to treatments by identifying four sets of factors that may influence decision-making:
Personal, situational, and global factors: Personal factors include demographic ones, such as age and gender, that cannot be changed as well as psychosocial ones, such as motivation and readiness to change, that one can alter. Situational factors can be changed by the individual's actions; an example is using the stairs whenever appropriate rather than the elevator. Global factors are those that influence the environment in which an individual lives, such as culture and views about weight; they typically change slowly over time from the efforts of large numbers of people. The availability and cost of a weight-loss program are two global factors that often influence a person's decision about whether or not to undertake a particular weight-loss program.
Health status and weight-related risk factors are factors that, as they worsen, may become an individual's primary motivation for losing weight. These factors are described in the section on Criterion 2.
Information and guidance come from a variety of sources, including the media (information and advertising); family, friends, and acquaintances (who relay their opinions and experiences with the various options); and health-care providers. The information and guidance may be sound or unsound, well intentioned or intended to deceive, and empowering or provoking inaction. They may also be incomplete or biased toward a particular program or approach that may not be suitable.
Experiencing a successful, partially successful, or unsuccessful outcome from an obesity-treatment program: This factor applies to those who have already gone through a program and are deciding whether to continue with the same program or try another one.
In some cases, it is possible to identify mismatches of individuals with weight-loss programs, at least in the sense of excluding people from particular options. For example, a healthy young woman with a BMI of 28 is no candidate for gastric surgery, whereas a very obese male with a BMI of 40 and hypertension—who has not lost weight despite many attempts—is not likely to be helped by a do-it-yourself diet book or exercise video. However, for most people who wish to lose weight, there is