Obesity
Conditions
Keywords
Obesity, Calcium carbonate, Dietary Supplements, Lipolysis
Brief summary
We hope to determine if supplementing the diet of women who habitually consume low levels of calcium, with 1500 mg of calcium a day for three months will increase fat oxidation and decrease fat storage. We will also measure concentrations of lipids, glucose, hormones and enzymes associated with fat and carbohydrate metabolism to determine alterations and mechanism of the metabolic changes.
Detailed description
The incidence of obesity has rapidly increased in recent years and reached epidemic proportions in the United States. Recent epidemiological data has shown an inverse relationship between calcium intake and body fat and emerging research suggests that inadequate dietary calcium consumption may increase obesity. Studies in mice have shown that an increase in dietary calcium consumption creates a shift in the utilization of energy stores from carbohydrates to fat and a shift in the partitioning of energy from storage (as fat) to expenditure (as heat). We will give 1500 mg of calcium a day for three months to women who habitually consume low levels of dietary calcium. The following measurements will be made before and after calcium supplementation: body fat by DEXA, lipolysis by infusion of stable isotopes of 1,1,2,3,3-\[2H5\] glycerol , hepatic glucose production by infusion of stable isotopes of 6,6-\[2H2\] glucose, lipogenesis by measurement of fatty acid synthase activity (14C radiochemical assay) , mRNA expression ( Real Time Polymerase Chain Reaction) and protein content (ELISA), indirect calorimetry measurement of non-protein respiratory quotient (NPRQ), energy expenditure, fat and carbohydrate oxidation. Serum calcium, glucose, cholesterol, triglycerides, LDL, HDL, parathyroid hormone, leptin, free fatty acids, adiponectin, 1,25(OH)2D, 25(OH)D and urinary calcium excretion will also be measured.
Interventions
DIETARY_SUPPLEMENTCalcium Carbonate
1500 mg per day
Sponsors
University of California, Davis
San Francisco General Hospital
USDA, Western Human Nutrition Research Center
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
FEMALE
Age
20 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
* BMI between 25 and 30 kg/m2 * Taking oral contraceptives * Having regular menses
Exclusion criteria
* Pregnant * History of metabolic bone, renal or thyroid disease, * History of diabetes mellitus, or gestational diabetes mellitus * Cigarette smoking * Self-administration of calcium supplements * Regular aerobic activity, i.e. jogging \> 1 mile/day
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Lipolysis by infusion of stable isotopes of 1,1,2,3,3-[2H5] glycerol | 0 and 3 months |
Secondary
| Measure | Time frame |
|---|---|
| Hepatic glucose production by infusion of stable isotopes of 6,6-[2H2] glucose | 0 and 3 months |
| Lipogenesis by measurement of fatty acid synthase activity (14C radiochemical assay) , mRNA expression ( Real Time Polymerase Chain Reaction) and protein content (ELISA) | 0 and 3 months |
| Indirect calorimetry measurement of non-protein respiratory quotient (NPRQ), energy expenditure, fat and carbohydrate oxidation | 0 and 3 months |
| Serum calcium, glucose, cholesterol, triglycerides, LDL, HDL, parathyroid hormone, leptin, free fatty acids, adiponectin, 1,25(OH)2D, 25(OH)D | 0 and 3 months |
| urinary calcium and sodium excretion | 0 and 3 months |
Countries
United States
Outcome results
None listed