Trial	Intervention(s) and comparator(s)	Duration of intervention (duration of follow‐up)	Description of participants	Trial period (year to year)	Country	Setting	Ethnic groups (%)	Duration of obesity (mean years (SD))
Atabek 2008	I: metformin + diet and physical activity advice	6 months (6 months)	Obese adolescents with hyperinsulinaemia	‐	Turkey	Hospital in/outpatient clinic/other based in University School of Medicine	‐	‐
	C: placebo + diet and physical activity advice
Berkowitz 2003	I: behavioural programme + sibutramine	6 months (6 months)	Obese adolescent boys and postmenarchal girls	March 1999 to August 2002	USA	University of Pennsylvania School of Medicine	White 49, black 49, other 2	‐
	C: behavioural programme + placebo						White 62, black 33, other 5
Berkowitz 2006	I: behavioural therapy programme + sibutramine	12 months (12 months)	Obese adolescents	July 2000 to February 2002	USA	33 weight loss clinics and outpatient clinic based in a University School of Medicine	White 56, African‐American 22, Hispanic or Mexican American 16, other 6	‐
	C: behavioural therapy programme + placebo						White 59, African‐American 19, Hispanic or Mexican‐American 14, other 9
Chanoine 2005	I: orlistat + diet + exercise + behavioural therapy	54 weeks (54 weeks)	Obese adolescents	August 2000 to October 2002	USA and Canada	32 clinical centres	White 75, black 19, other 6	‐
	C: placebo + diet + exercise + behavioural therapy						White 78, black 14, other 8
Clarson 2009	I: metformin + lifestyle intervention	6 months (6 months)	Obese adolescents with insulin resistance	Enrolled 2005 to 2007	Canada	Participants assessed in community clinic and there were monthly visits to clinic during intervention. Intervention carried out in community ‐ at adolescent's home ‐ unclear where group sessions took place	‐	‐
	C: lifestyle intervention only
Franco 2014	I: sibutramine + dietary guidance	6 months (6 months)	Obese adolescents	‐	Brazil	Paediatric endocrinology outpatient clinic in childhood obesity group of the Instituto da Crianca do Hospital das Clinicas de Faculdade de Medicina de Universidade de Sao Paulo	‐	‐
	C: placebo + dietary guidance
Freemark 2001	I: metformin	6 months (6 months)	Obese adolescents with fasting hyperinsulinaemia and a family history of type 2 diabetes	‐	USA	Inpatient and outpatient clinic of a university	White 64, black 36	‐
	C: placebo						White 47, black 53
Garcia‐Morales 2006	I: sibutramine + diet + exercise	6 months (6 months)	Obese Mexican adolescents	August 2001 to August 2003	Mexico	Outpatients attending the endocrinology department of the Federico Gomez Children's Hospital of Mexico	‐	‐
	C: placebo + diet + exercise
Godoy‐Matos 2005	I: sibutramine + hypocaloric diet + exercise	7 months (7 months)	Obese adolescents	January 2002 to April 2003	Brazil	Regular clinical setting	‐	‐
	C: placebo + hypocaloric diet + exercise
Kendall 2013	I: metformin + healthy lifestyle advice	6 months (6 months)	Obese children and adolescents with hyperinsulinaemia or impaired fasting glucose or impaired glucose tolerance (or both)	‐	UK	UK paediatric endocrine centres	White 80, Asian 19, Afro‐Caribbean 11	‐
	C: placebo + healthy lifestyle advice						White 72, Asian 26, Afro‐Caribbean 1
Maahs 2006	I: orlistat + diet and exercise therapy	26 weeks (26 weeks)	Obese adolescents	December 2002 to September 2003	USA	General clinical research centre at University of New Mexico Hospital	Hispanic 60	‐
	C: placebo + diet and exercise therapy						Hispanic 65
Mauras 2012	I: metformin + diet/exercise intervention	6 months (6 months)	Obese children with normal glucose tolerance but elevated hsCRP or fibrinogen concentrations (or both)	‐	USA	‐	White 51, African‐American 37, other 11	Uncomplicated (exogenous) obesity for < 5 years
	C: diet/exercise intervention						White 39, African‐American 42, other 19
NCT00001723	I: orlistat + behavioural weight loss programme	6 months (6 months)	Obese children and adolescents with obesity‐related diseases	RCT began in 1999 and ended in 2008	USA	National Institutes of Health Clinical Center	Non‐Hispanic black 63, non‐Hispanic white 37	‐
	C: placebo + behavioural weight loss programme						Non‐Hispanic black 60, non‐Hispanic whites 40
Ozkan 2004	I: conventional treatment + orlistat	Intervention group was followed for 5 to 15 months (mean duration of treatment 11.7, SD 3.7 months)	Adolescents with severe exogenous obesity	‐	Turkey	Outpatient clinic	‐	‐
	C: conventional treatment	Control group was followed for 6 to 17 months (mean 10.2, SD 3.7 months)
Prado 2012	I: metformin + nutritional guide and exercise programme	3 months (6 months)	Obese female adolescents at risk of developing type 2 diabetes	June 2009 to July 2010	Chile	Conducted at Center of Adolescent Health Serjoven	‐	‐
	C: placebo + nutritional guide and exercise programme
Rezvanian 2010	I1: metformin + healthy eating and physical activity advice	12 weeks (24 weeks)	Obese children and adolescents	‐	Iran	Pediatric Obesity and Metabolic Syndrome Research Clinic of the Pediatric Preventive Cardiology Department, Isfahan Cardiovascular Research Center	‐	‐
	I2: fluoxetine + healthy eating and physical activity advice
	I3: metformin and fluoxetine + healthy eating and physical activity advice
	C: placebo + healthy eating and physical activity advice
Srinivasan 2006	I: metformin first then placebo + standardised information on healthy eating and exercise	6 months (12 months)	Obese children and adolescents (aged 9 to 18) with suspected insulin resistance	‐	Australia	Outpatient clinic of a tertiary paediatric hospital (university teaching hospital)	64% were from ethnic backgrounds with high prevalence of insulin resistance and the metabolic syndrome (e.g. Indian subcontinent, Pacific Islands), 25% were from a northern European background, and 11% were from a mixed background	‐
	C: placebo first then metformin + standardised information on healthy eating and exercise
Van Mil 2007	I: sibutramine + energy‐restricted diet and exercise plan	12 weeks (24 weeks)	Obese adolescents	‐	The Netherlands	Outpatient clinic	‐	‐
	C: placebo + energy‐restricted diet and exercise plan
Wiegand 2010	I: metformin + multiprofessional lifestyle intervention	6 months (6 months)	Obese insulin‐resistant adolescents	May 2006 to December 2006	Germany and Switzerland	Paediatric obesity centre	White 87, other 13	‐
	C: placebo + multiprofessional lifestyle intervention						White 92, other 9
Wilson 2010	I: metformin + lifestyle intervention programme	52 weeks (100 weeks)	Obese adolescents	October 2003 to August 2007	USA	6 Glaser paediatric research centres	White 56, African‐American 21, Asian 8, other 15, Hispanic ethnicity 18	‐
	C: placebo + lifestyle intervention programme						White 71, African‐American 16, Asian 0, other 13, Hispanic ethnicity 29
Yanovski 2011	I: metformin + dietitian‐administered weight‐reduction programme	6 months (12 months)	Obese insulin‐resistant children	September 2000 to August 2008	USA	Trial took place at the NIH clinical research centre	Non‐Hispanic white 42, Non‐Hispanic black 42, Hispanic white 11, other 5	‐ ‐
	C: placebo + dietitian‐administered weight‐reduction programme						Non‐Hispanic white 49, Non‐Hispanic black 38, Hispanic white 11, other 2
"‐" denotes not reported. C: comparator; hsCRP: high sensitivity C‐reactive protein; I: intervention; RCT: randomised controlled trial; SD: standard deviation.