Insulin Resistance, Obesity
Conditions
Keywords
obesity, weight loss, insulin resistance
Brief summary
This study will evaluate the potential beneficial cardiometabolic effect of moderate (5%) weight loss and progressive (5%, 10%, and 15%) weight loss in obese adults without diabetes. Participants will be randomly assigned to one of 2 groups. Group 1: supervised weight loss group (low-calorie diet). Group 2: supervised weight maintenance group (normal diet). Of those assigned to group 1, half of the participants will lose 5% of their body weight and the other half will lose 5%, 10%, and 15% of their weight over time under the guidance of a dietitian. Research testing will be repeated at each time point (5%, 10%, and 15% weight loss). In group 2, research testing will be repeated after six months.
Interventions
BEHAVIORALWeight Maintenance
Subjects in the weight maintenance arm will maintain a steady body weight (plus or minus 2% of initial body weight) for six months.
BEHAVIORALWeight Loss
Half of the subjects in the weight loss arm will lose 5% of their weight through a low-calorie diet, and half will also lose 10% and 15% body weight.
Sponsors
Washington University School of Medicine
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
21 Years to 65 Years
Healthy volunteers
No
Inclusion criteria
* Obese: Body Mass Index from 30 to 45 * Insulin Resistant: HOMA-IR score greater than or equal to 2
Exclusion criteria
* diabetes * smoking * pregnancy * breastfeeding * heart failure * history of liver disease including hepatitis * alcoholism * exercise more than 2 hours per week
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Insulin Sensitivity | baseline through weight loss (approximately one year) | In the weight-loss arm we will measure insulin sensitivity at baseline, after 5% weight loss, after 10% weight loss and again after 15% weight loss. Each weight loss phase will last an average of four months for a total of approximately one year. In the weight maintenance arm we will measure insulin sensitivity at baseline and after six months. |
| intra-hepatic triglyceride | baseline through weight loss (approximately one year) | In the weight-loss arm we will measure intra-hepatic triglyceride at baseline, after 5% weight loss, after 10% weight loss and again after 15% weight loss. Each weight loss phase will last an average of four months for a total of approximately one year. In the weight maintenance arm we will measure intra-hepatic triglyceride at baseline and after six months. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| total cholesterol | baseline through weight loss (approximately one year) | In the weight-loss arm we will measure total cholesterol at baseline, after 5% weight loss, after 10% weight loss and again after 15% weight loss. Each weight loss phase will last an average of four months for a total of approximately one year. In the weight maintenance arm we will measure total cholesterol at baseline and after six months. |
| systolic blood pressure | baseline through weight loss (approximately one year) | In the weight-loss arm we will measure systolic blood pressure at baseline, after 5% weight loss, after 10% weight loss and again after 15% weight loss. Each weight loss phase will last an average of four months for a total of approximately one year. In the weight maintenance arm we will measure systolic blood pressure at baseline and after six months. |
| Cell proliferation (growth) rates in the colon - optional procedure | baseline through weight loss (approximately four months to one year) | Colon cell proliferation rates will be determined using stable isotope labelled tracer methods in conjunction with sigmoid colon biopsy samples. In the weight-loss arm we will measure colonocyte proliferation rate at baseline, and once again after weight loss (either 5% weight loss, or 10% weight loss, or 15% weight loss; i.e. only one time after weight loss). Each weight loss phase will last an average of four months for a total of approximately one year. In the weight maintenance arm we will measure colonocyte proliferation rate at baseline and after six months. |
Countries
United States
Outcome results
None listed