Obesity is a substantial public health concern. One subgroup that has shown a large increase in prevalence of obesity is adolescents (12 - 19 years) (CDC, 2014; Altman & Wilfley, 2014; Odgen et al., 2010; Ogden, et al., 2012; Ogden, et al., 2014). This is concerning for two reasons: (a) the strong likelihood of obesity persisting into adulthood (CDC, 2014) leading to co-occurring medical and psychosocial problems (Altman & Wilfley, 2014; Kelsey et al., 2014), and (b) there are few studies demonstrating successful reductions in obesity in children and even fewer successful demonstrations in adolescents (Altman & Wilfley, 2014; Tsiros et al., 2008).
One way to evaluate the behaviors related to obesity is through an individual’s choice-making behavior between foods and exercises. Behavior Economic Theory (BET) is an operant methodology used to assess choice making and to describe relationships between choices. The purpose of this study was to describe the relationship between diet and exercise, through the BET framework, in adolescent females who are obese within a single case design. Participants’ recorded daily perceived calories consumed and expended with a concurrent schedules design using an electronic self-monitoring program for baseline (Phase 1). After Phase 1, the researcher presented a choice between diet and exercise and developed a behavioral contract with goals addressing that choice for Phase 2. A subsequent behavioral contract was developed to target the changes in diet or exercise in Phase 3. The participants continued to record daily consumption and expenditure during Phases 2 and 3. IOA was collected by two researchers who independently reviewed the recorded consumed and expended calories on at least 30% of days that the participant self-monitored. For all participants, IOA was calculated across 35.8% of days with an average 96.6% agreement.
The results showed that 3 of 5 participants preferred to develop a behavioral contract which targeted exercise, but only one showed weight loss. Two of the 5 participants chose to target diet with the contracts. Similar to the exercise group, weight loss occurred for only one participant. Using the BET methodology to analyze the participant’s engagement in reducing calories, only participants that simultaneously worked on increasing exercise and reducing their calorie intake lost weight, showing a complementary relationship between diet and exercise. Regardless of intervention strategy, these results suggest that adolescent females may have to develop a complementary relationship between diet and exercise to achieve successful outcomes. These results suggest that further analysis of the relationship between diet and exercise are warranted.