title: A randomized controlled trial to investigate the impact of a low glycemic index (GI) diet on body mass index in obese adolescents.
abstract: 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).
  
  
  CONCLUSIONS
  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.
  
  
  BACKGROUND
  ClinicalTrials.gov Ref. No: NCT01278563.
authors.forename: Alice P S
authors.initials: AP
authors.lastname: Kong
authors.affiliation: Nethersole School of Nursing, The Chinese University of Hong Kong, Hong Kong SAR, Shatin, N,T,, Hong Kong, SAR, China. kchoi@cuhk.edu.hk.
authors.forename: Kai Chow
authors.initials: KC
authors.lastname: Choi
authors.forename: Ruth S M
authors.initials: RS
authors.lastname: Chan
authors.forename: Kris
authors.initials: K
authors.lastname: Lok
authors.forename: Risa
authors.initials: R
authors.lastname: Ozaki
authors.forename: Albert M
authors.initials: AM
authors.lastname: Li
authors.forename: Chung Shun
authors.initials: CS
authors.lastname: Ho
authors.forename: Michael H M
authors.initials: MH
authors.lastname: Chan
authors.forename: Mandy
authors.initials: M
authors.lastname: Sea
authors.forename: C Jeyakumar
authors.initials: CJ
authors.lastname: Henry
authors.forename: Juliana C N
authors.initials: JC
authors.lastname: Chan
authors.forename: Jean
authors.initials: J
authors.lastname: Woo
mesh_terms: D000293:Adolescent; D016497:Adolescent Health Services; D015992:Body Mass Index; D001835:Body Weight; D004038:Diet, Reducing; D004040:Dietary Carbohydrates; D005247:Feeding Behavior; D005260:Female; D038321:Glycemic Index; D006723:Hong Kong; D006801:Humans; D008019:Life Style; D008297:Male; D009765:Obesity / Q000097:blood / Q000178:diet therapy*; D016896:Treatment Outcome; D055105:Waist Circumference
chemical_list: D004040:Dietary Carbohydrates