The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Retrospectively registered

Titles & IDs
Public title
The effect of diet on acne in adolescent males
Scientific title
The effect of the glycemic index of carbohydrates on facial acne vulgaris lesion severity and hormones in adolescent males over 8 weeks
Secondary ID [1] 1561 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Acne vulgaris 257040 0
Condition category
Condition code
Skin 257200 257200 0 0
Dermatological conditions
Diet and Nutrition 257210 257210 0 0
Other diet and nutrition disorders

Study type
Description of intervention(s) / exposure
Adolescent males were alternately allocated to the intervention treatment (low glycemic index (GI) diet) or the comparator treatment (high GI diet) for a period of 8 weeks. Low GI foods included verified low GI brands of muesli and a processed fruit snack, and lasagne (average daily GI of low GI diet intervention was 51). Macronutrient and energy intakes were similar between this intervention group and the comparison group (high GI). Severity of inflammatory lesions on the face, insulin sensitivity (homeostasis modelling assessment of insulin resistance), androgens and insulin-like growth factor-1 and its binding proteins were assessed at baseline and 8 wk, a period corresponding to the school term.
Intervention code [1] 256215 0
Intervention code [2] 256216 0
Treatment: Other
Comparator / control treatment
The comparator treatment was a high GI diet administered over 8 weeks. This was assumed to be a reflection of a typical teenage diet. This diet included verified high GI brands of wheat breakfast biscuits and a processed fruit snack, and baked potato with chili con carne. The average daily GI consumed was 61. Macronutrient and energy intakes were similar between this comparison group and the intervention group (low GI).
Control group

Primary outcome [1] 258090 0
Severity of facial acne lesions as outlined below. A dermatologist who was blind to diet allocation assessed facial acne severity by examining the number and degree of inflammation of inflammatory lesions (papules, pustules and nodules, not comedones or scars) on the face under bright lighting. Acne was graded on a scale from 0 to 3: 0 = no acne, 1 = mild, 2 = moderate and 3 = severe. Photographs were taken of the forehead and right and left cheeks. Two subjects were chosen at random for repeat assessment by the same dermatologist to determine intra-observer variation (0%). When illness precluded the attendance of the first dermatologist, a second dermatologist completed some of the final assessments. The first dermatologist later graded photographs from these assessments and an average was taken from the two grades of facial acne severity.
Timepoint [1] 258090 0
0 and 8 wk
Secondary outcome [1] 263698 0
Blood variables:
Glucose (mmol/L)
Insulin (pmol/L)
Testosterone (nmol/L)
SHBG (nmol/L)
FAI (nmol/L)
DHEA-S (?mol/L)
IGF-1 (nmol/L)
IGFBP-1 (ng/mL)
IGFBP-3 (?g/mL)

DHEA-S = dehydroepiandrosterone-sulfate, FAI = free androgen index, HOMA-IR = homeostasis modelling assessment of insulin resistance, IGF-1 = insulin-like growth factor-1, IGFBP-1 and -3 = insulin like growth factor binding proteins -1 and -3, SHBG = sex hormone binding globulin.
Timepoint [1] 263698 0
0 and 8 wk

Key inclusion criteria
Healthy adolescent males with acne at a secondary boarding school in Sydney, Australia: acne severity grade 1, 2 or 3, stable weight over the past 3 months and parental/guardian consent.
Minimum age
10 Years
Maximum age
19 Years
Can healthy volunteers participate?
Key exclusion criteria
The previous use of isotretinoin, antibiotics in the past month, excessive alcohol intake, illicit drugs, smoking, physical or mental illness, food allergy or intolerance, vegetarianism, previous surgery on the gastrointestinal system, black skin (due to difficulty in visualising lesions), or final school examinations in the coming months.

Study design
Purpose of the study
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Subjects were alternately allocated to either a high or low GI diet in order of recruitment and allocation was not concealed.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Subjects were alternately allocated to either a high or low GI diet in order of recruitment
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)

Funding & Sponsors
Funding source category [1] 256716 0
Name [1] 256716 0
The University of Sydney
Address [1] 256716 0
Human Nutrition Unit, School of Molecular Bioscience G08, The University of Sydney, NSW 2006
Country [1] 256716 0
Primary sponsor type
The University of Sydney
Human Nutrition Unit, School of Molecular Bioscience G08, The University of Sydney, NSW 2006
Secondary sponsor category [1] 256004 0
Name [1] 256004 0
Address [1] 256004 0
Country [1] 256004 0
Other collaborator category [1] 1169 0
Name [1] 1169 0
Department of Dermatology, Central Clinical School, The University of Sydney
Address [1] 1169 0
C22 Concord Hospital, 1 Hospital Road,
Concord, NSW 2137
Country [1] 1169 0
Other collaborator category [2] 1170 0
Name [2] 1170 0
Macquarie University
Address [2] 1170 0
Department of Statistics, Balaclava Road, North Ryde, NSW 2109, Australia
Country [2] 1170 0

Ethics approval
Ethics application status
Ethics committee name [1] 258728 0
The University of Sydney Human Research Ethics Committee.
Ethics committee address [1] 258728 0
Research Office
Level 6, Jane Foss Russell Building G02
The University of Sydney NSW 2006
Ethics committee country [1] 258728 0
Date submitted for ethics approval [1] 258728 0
Approval date [1] 258728 0
Ethics approval number [1] 258728 0

Brief summary
We hypothesised that in the context of weight maintenance and identical macronutrient (e.g. carbohydrate) and fibre intake, the replacement of high GI carbohydrates with low GI carbohydrates would improve acne severity by lowering blood insulin concentrations. We studied adolescent males attending boarding school so that food intakes could be more easily controlled.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 30985 0
Address 30985 0
Country 30985 0
Phone 30985 0
Fax 30985 0
Email 30985 0
Contact person for public queries
Name 14232 0
Professor Jennie Brand-Miller
Address 14232 0
Human Nutrition Unit, School of Molecular Bioscience G08, The University of Sydney, NSW 2006
Country 14232 0
Phone 14232 0
+61 2 9351 3759
Fax 14232 0
+61 2 9351 6022
Email 14232 0
Contact person for scientific queries
Name 5160 0
Professor Jennie Brand-Miller
Address 5160 0
Human Nutrition Unit, School of Molecular Bioscience G08, The University of Sydney, NSW 2006
Country 5160 0
Phone 5160 0
+61 2 9351 3759
Fax 5160 0
+61 2 9351 6022
Email 5160 0

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary