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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
Long-term health effects of high and low carbohydrate diets in obese subjects
with the metabolic syndrome
Scientific title
Long-term health effects of high and low carbohydrate, weight loss diets in obese subjects with the metabolic syndrome
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Obesity 1181 0
Condition category
Condition code
Diet and Nutrition 1264 1264 0 0

Study type
Description of intervention(s) / exposure
participants will be randomised for the 52 week intervention duration to either;
1. Low carbohydrate diet:35% protein,
61% fat (20% saturated fat)
4% carbohydrate

2. High carbohydrate,low fat diet:18% protein, 27% fat (<8% saturated fat)
55% carbohydrate
Intervention code [1] 1017 0
Comparator / control treatment
1. Low carbohydrate diet:35% protein,
61% fat (20% saturated fat)
4% carbohydrate
Control group

Primary outcome [1] 1702 0
Weight loss
Timepoint [1] 1702 0
At 8 weeks and 52 weeks after start of diet intervention
Secondary outcome [1] 3054 0
Lipids, insulin, glucose, blood pressure, body composition, flow mediated dilatation, physical function, psychological health, bone health & renal function and nutrition adequacy.
Timepoint [1] 3054 0
At 8 and 52 weeks after start of diet intervention.

Key inclusion criteria
High waist circumferenceat least one cardiovascular risk factor.
Minimum age
18 Years
Maximum age
65 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Have proteinuria, a malignancy, or a history of metabolic disease such as liver, kidney, cardiovascular, respiratory or gastrointestinal disease, diabetes (fasting blood glucose or are pregnantUncontrolled hypertension (resting recumbent BP >160/110 mmHg).

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
allocation is not concealed
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
random allocation using computer software clinstat
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?

Intervention assignment
Other design features
two dietary patterns
Phase 4
Type of endpoint(s)
Statistical methods / analysis

Recruitment status
Active, not recruiting
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] 1383 0
Name [1] 1383 0
national heart foundation of Australia
Address [1] 1383 0
Country [1] 1383 0
Funding source category [2] 1384 0
Government body
Name [2] 1384 0
national health & medical research council of Australia
Address [2] 1384 0
Country [2] 1384 0
Primary sponsor type
Government body
national health & medical research council of Australia
Secondary sponsor category [1] 1218 0
Name [1] 1218 0
national heart foundation
Address [1] 1218 0
Country [1] 1218 0

Ethics approval
Ethics application status
Ethics committee name [1] 2734 0
CSIRO Human Nutrition
Ethics committee address [1] 2734 0
Adelaide, South Australia
Ethics committee country [1] 2734 0
Date submitted for ethics approval [1] 2734 0
Approval date [1] 2734 0
Ethics approval number [1] 2734 0

Brief summary
Obesity is a major health problem, which contributes to significant morbidity and mortality in Australia. Energy restriction and exercise are commonly advocated as lifestyle approaches for the modification of cardiovascular disease risk factors such as obesity, hyperlipidemia, impaired glucose tolerance, and insulin resistance. In response to the increasing concerns about the rising level of obesity, there has been a multitude of “fad” diets developed outside the medical and nutritional recommendations for healthy eating and with this an increased popularity of diets very low in carbohydrates. However, due to the scant scientific evidence available for the long-term efficacy and safety of these diets, and their impact on risk factors for cardiovascular disease, cancer, renal function, bone health, psychosocial function and the capacity to undertake concurrent physical activity, there is a lack of evidenced-based public health recommendations and policy regarding these dietary patterns. This study will provide scientific evidence to validate optimum dietary recommendations for weight loss that can be used by health professionals who have a strong need for a rational basis for their advice to counsel obese patients.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 36110 0
Address 36110 0
Country 36110 0
Phone 36110 0
Fax 36110 0
Email 36110 0
Contact person for public queries
Name 10206 0
Dr Grant Brinkworth
Address 10206 0
CSIRO Human Nutrition
PO Box 10041
Adelaide BC SA 5000
Country 10206 0
Phone 10206 0
+61 8 83038830
Fax 10206 0
+61 8 8303 8899
Email 10206 0
Contact person for scientific queries
Name 1134 0
Dr Grant Brinkworth
Address 1134 0
CSIRO Human Nutrition
PO Box 10041
Adelaide BC SA 5000
Country 1134 0
Phone 1134 0
+61 8 83038830
Fax 1134 0
+61 8 8303 8899
Email 1134 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