A randomized controlled trial to investigate the impact of a low glycemic index (GI) diet on body mass index in obese adolescents.

BACKGROUND: The role of a low glycemic index (GI) diet in the management of adolescent obesity remains controversial. In this study, we aim to evaluate the impact of low GI diet versus a conventional Chinese diet on the body mass index (BMI) and other obesity indices of obese adolescents. METHODS: Obese adolescents aged 15-18 years were identified from population-recruited, territory-wide surveys. Obesity was defined as BMI ≥95th percentile of Hong Kong local age- and sex-specific references. Eligible subjects were randomized to either an intervention with low GI diet (consisting of 45-50% carbohydrate, 30-35% fat and 15-20% protein) or conventional Chinese diet as control (consisting of 55-60% carbohydrate, 25-30% fat and 10-15% protein). We used random intercept mixed effects model to compare the differential changes across the time points from baseline to month 6 between the 2 groups. RESULTS: 104 obese adolescents were recruited (52 in low GI group and 52 in control group; 43.3% boys). Mean age was 16.7 ± 1.0 years and 16.8 ±1.0 years in low GI and control group respectively. 58.7% subjects completed the study at 6 months (65.4% in low GI group and 51.9% in control group). After adjustment for age and sex, subjects in the low GI group had a significantly greater reduction in obesity indices including BMI, body weight and waist circumference (WC) compared to subjects in the control group (all p <0.05). After further adjustment for physical activity levels, WC was found to be significantly lower in the low GI group compared to the conventional group (p = 0.018). CONCLUSION: Low GI diet in the context of a comprehensive lifestyle modification program may be an alternative to conventional diet in the management of obese adolescents. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Ref. No: NCT01278563.

Randomized, double-blind, placebo-controlled trial of herbal therapy for children with asthma.

OBJECTIVES: The purpose of this trial was to evaluate whether the herbal formula of CUF2 used as complementary therapy improves the clinical symptoms and biochemical markers in children with asthma using inhaled corticosteroids. PATIENTS AND METHODS: In a double-blind, placebo-controlled prospective trial, 85 children with asthma aged 7-15 years were randomly assigned to receive either a daily oral herbal formula of 0.619-g CUF2 capsule of dried aqueous extract with an equal weight of five herbs (Astragalus mongholius Bunge, Cordyceps sinensis Sacc., Radix stemonae, Bulbus fritillariae cirrhosae, and Radix scutellariae) or placebo for 6 months. RESULTS: The primary endpoint was the change in steroids dosage; the secondary outcomes included the disease severity score, lung function test, and biochemical markers in blood. Eighty-five (85) children (42 on active treatment and 43 on placebo) completed the 6-month clinical trial. Children randomized to the herbal formula of CUF2 and the placebo showed a similar improvement in clinical symptoms and biomedical markers. The comparison between the CUF2 group and the placebo group showed no significant difference on the dosage of steroids (-2.3 versus -3.1 mg, p = 0.915), disease severity score (-2.3 versus -3.1, p = 0.215), and lung function test of forced expiratory volume in 1 second/forced vital capacity percent (0.1 versus 0.6%, p = 0.809) and peak expiratory flow rate (-7.3 versus -0.6 l/minutes, p = 0.118). No significant difference was found between the two study groups in the biochemical outcomes measured. The intervention effect of CUF2 was smaller than the placebo effect. CONCLUSIONS: This study provides no evidence to support the use of the herbal formula of CUF2 in children with asthma. Parents are thus advised to discuss with health professionals before choosing an herbal formula in preference to conventional treatment modes.