Page 128 - Go4it

Chapter 8
consequence of insulin resistance which can cause hyperglycaemia and ultimately type 2 diabetes mellitus (12-14).
In the Go4it study, we only found significant treatment effects in adolescents from western descent (mean BMIsds reduction of 0.35) on body composition and metabolic components (systolic and diastolic blood pressure and HDL cholesterol level). Unfortunately, we were not able to show significant reductions in insulin levels. These results are in line with the observations of Ford et al. that improvements in body composition and metabolic components in obese adolescents can be expected with BMIsds reduction of ≥ 0.25 (15). Of the 6 comparable randomised controlled trials evaluating treatment programs for obese adolescents (9;12-15), only 2 studied the impact of the intervention on metabolic components. Both studies found no significant reductions in the metabolic components.
Questionnaires (dietary and activity behaviour)
Dietary behaviour, physical activity and sedentary behaviour were assessed by self-report. Dietary behaviour was classified in: drinking behaviour (sugar- containing beverages (soft drinks and fruit juice), diet soft drinks, water and milk beverages), eating in between meals (snacks, low energy snacks, fruit and vegetables) and breakfast frequency (days per week) (16). The questions were based on validated questionnaires, for assessing dietary intake and referred to the past 7 days (17,18). Physical activity and sedentary behaviour were assessed with the Activity Questionnaire for Adolescents and Adults (AQuAA) (19). The AQuAA assessed the amount of minutes per week spent on light, moderate and vigorous-intensity physical activity, as well as time spent watching TV and using the computer and refers to activities in the past week (7- day recall). It took the adolescents approximately 60 minutes to complete the questionnaires. Many adolescents found this too long and very boring. The use of self-report is also subject to recall bias and dependent of participant understanding and motivation. Unrealistic values concerning drinking behaviour, values above the 95th percentile, were recoded as the value of the 95th percentile. After this adjustment, the mean intake of beverages (soft, fruit, diet, milk and water) was still >3000 ml a day. 53% of the adolescents also provided unrealistic answers (>16 hours of activity a day) to the questions on physical and sedentary behavior (AQuAA). These unrealistic answers proved the limited validity of the questionnaire in our sample. For this reason, we decided not to publish these data.
Cost diaries
As part of the Go4it study, also an economic evaluation was performed. As the economic evaluation was conducted from a societal perspective, all costs were collected, regardless of who paid for them. These costs included direct costs of health care utilization, namely the costs of the Go4it intervention, visits to the
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