Clinical trial NCT01460797: Metabolic Effects of a Caloric Restriction High/Low Glycemic Index Diet Plus Metformin in Overweight/Obese Subjects
Official title: Effects of a Caloric Restriction High/Low-glycemic Index Diets and in Combination With Metformin on Glucose Metabolism, Lipid Profile and Body Composition in Overweight/Obese Subjects
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Obesity
Keywords: Glycemic index
Caloric restriction
Energy intake
Glucose
Lipid Metabolism
Cholesterol
HDL Cholesterol
LDL Cholesterol
Obesity
Metformin
Lead sponsor: University of Brasilia
Sponsor class: OTHER
Collaborators: name: University of Brasilia
name: Conselho Nacional de Desenvolvimento Científico e Tecnológico
name: Fund to support research of the Federal District, Brazil
First posted: 2011-10-27
Enrollment: 41
Sex: ALL
Minimum age (years): 18
Maximum age (years): 50
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: The prevalence of obesity and Type 2 diabetes has increased dramatically worldwide. Research on Glycemic Index (GI) diets has been largely developed, however the combination with metformin in humans was not investigated yet. We hypothesized that the low-GI diet in combination with metformin would elicit greater improvements on glucose metabolism, lipid profile and body composition on overweight or obese type 1 subjects. This study aims to evaluate the metabolic effects of the adoption of dietary advice to follow caloric restriction high/low GI diets, and low-GI diet associated with metformin on glucose metabolism, lipid profile and body composition on overweight or obese type 1 subjects.

Detailed description: All groups (Low/High-GI and Low-GI + Metformin) showed significant reduction in anthropometric parameters, but only Low-GI and Low-GI + Metformin groups have an improvement in body composition parameters. In addition, the Low-GI group achieved better results in metabolism of carbohydrates (glucose, insulin, Cederholm Index, and HOMA-β) and lipids (Chol, TAG, LDL-C, VLDL-C, and TC/HDL-c). These results show the benefits of Low-GI diet on metabolic parameters in overweight or obese type 1 subjects.

Eligibility criteria: Inclusion Criteria:

* Participants were adults (18-50 y), with body mass index (BMI) between 25-35 kg/m².
* Subjects with adequate glycemic and insulinemic response after oral glucose tolerance test: Hypocaloric diet with predominating high glycemic index foods;
* Subjects with altered glycemic response presented at the 120 min point either glycemia \<140mg/dL and insulin level \>40 µUI/ml: Hypocaloric diet with predominant low glycemic index foods;
* Subjects with impaired glucose tolerance presented at the 120 min point glycemia 140 - 199mg/dL and insulin \>40 µUI/ml: Hypocaloric diet with predominant low glycemic index foods and metformin.

Exclusion Criteria:

* Smokers
* Pregnant or lactating
* Diagnosis of any metabolic diseases
* Were under medication and therapeutic diet, except oral contraceptive for women.

Primary outcomes:
measure: Glucose Metabolism
timeFrame: 0 and 4 months
Secondary outcomes:
measure: Lipid Profile
timeFrame: 0 and 4 months
measure: Body Composition
timeFrame: 0 and 4 months
measure: Clinical Assessment
timeFrame: 0 and 4 months
measure: Food Intake
timeFrame: 0 and 4 months
Other outcomes:
Locations:
city: Brasília
country: Brazil
facility: School of Health Sciences, University of Brasília
state: DF
Study officials:
affiliation: University of Brasilia
name: Teresa HM da Costa, Ph.D.
role: STUDY_DIRECTOR
References: