Weight loss in adolescents: Measuring benefits and outcomes

One in five Queensland children are overweight or obese; however the lack of weight management services remains a major barrier to families seeking assistance. Evidence indicates that childhood obesity is resistant to treatment and tends to track into adulthood, bringing with it the associated risk of chronic disease. There is a need for effective treatment pathways, particularly for adolescents with severe obesity. Dietetics provides the opportunity to impact on childhood obesity but traditionally has relied on standard advice based on unstructured low fat eating. Evidence in adults suggests that a reduction in dietary carbohydrate could provide an alternative dietary pattern. A 12 week pilot study (n=30 participants, mean age 13 years, mean body mass index (BMI) z-score 2.2) investigated the feasibility and acceptability of a structured reduced carbohydrate dietary plan (energy distribution: fat 35%: protein 30%: carbohydrate 35%) and a structured low fat dietary plan (25% fat: protein 20%: carbohydrate 55%) compared with ‘standard care’ (an unstructured low fat approach). Participants self-selected which dietary program they commenced and attended 6 nutrition counselling appointments. Only two individuals chose the ‘standard care’ option, 13 chose the structured low fat option and 15 chose to modify their carbohydrate intake. Participants indicated a strong preference for structured dietary advice. This pilot study highlighted that food records had high levels of implausible energy intakes (53% of participants) but macronutrient distribution appeared to be unaffected by under-reporting and was a useful method to gauge dietary compliance. Participants were very sedentary and were unable to alter their physical activity; had a range of biochemical abnormalities and had evidence of psychosocial issues including school absence. Mean BMI z-score loss was -0.20 in the structured low fat group, -0.11 in the reduced carb group and those choosing ‘standard care’ gained weight (+3.1kg) over the 12 week period (mean BMI z-score change -0.02). The outcomes demonstrated that the referral pathways were successful and that families had a preference for a structured eating plan approach. A 12 week randomised controlled trial entitled the ‘Eat Smart’ study was conducted with the primary aim to evaluate the relative efficacy of a structured low fat versus a structured reduced carbohydrate eating plan versus a control group; the primary outcome measure was BMI z-score. A psychological preparedness group program provided a preliminary step to ensure that all subjects entering the dietary phase were psychologically stable and ready for change. Of 87 individuals (mean age 13.3 years, 79% female) randomised, 79 completed (90.8%) the 12 week intervention period. At week 12 there was a significant overall association between diet and BMI z-score (p