Title page for ETD etd-07282004-174858


Type of Document Dissertation
Author Coleman, Mary Dean
URN etd-07282004-174858
Title Effect of a Low-Carbohydrate, High-Protein Diet on Bone Mineral Density, Biomarkers of Bone Turnover, and Calcium Metabolism in Healthy Pre-Menopausal Females
Degree PhD
Department Human Nutrition, Foods, and Exercise
Advisory Committee
Advisor Name Title
Nickols-Richardson, Sharon M. Committee Chair
Gwazdauskas, Francis C. Committee Member
Herbert, William G. Committee Member
Ramp, Warren K. Committee Member
Thye, Forrest W. Committee Member
Keywords
  • bone mineral density
  • weight-loss
  • high-protein
  • obesity
  • low-carbohydrate diet
Date of Defense 2004-07-15
Availability unrestricted
Abstract
Low-carbohydrate, high-protein (LCHP) diets have been shown to induce weight loss and beneficial changes in blood lipids that suggest cardiovascular disease risk reduction; however, LCHP diets have not been adequately investigated for health effects on the skeleton. A randomized trial to determine the effects of a LCHP diet on bone mineral status, biomarkers of bone turnover, indicators of acid-base balance, calcium homeostasis and fasting lipids in healthy pre-menopausal women was conducted. Women, aged 32 - 45 y, with a body mass index between 25-41 kg/m2 were randomized into one of two diet groups: LCHP (n = 13) or high-carbohydrate, low-fat (HCLF) (n = 12). Anthropometric (body weight, lean mass, fat mass) and bone mineral density (BMD) and content (BMC) measures and markers of lipid metabolism were taken at weeks 0, 6, and 12. Measures of acid-base balance, protein metabolism, and calcium homeostasis were conducted at weeks 0, 1-4, 6, and 12. Serum osteocalcin was analyzed at weeks 0, 1, 2, 6, and 12, while urinary NTx was analyzed at weeks 0, 1 and 2. Weight loss was significant at the end of 12 weeks in both diet groups (P < 0.05) but there was no Diet x Time interaction. Total proximal femur BMD was lower in the LCHP group (P < 0.05) compared to the HCLF group by week 12. Femoral neck BMC decreased in the LCHP diet group (P < 0.05), whereas total forearm BMC increased (P < 0.05) in the HCLF diet group by week 12 of the study. Serum osteocalcin showed significant main effects of diet (P < 0.05) and time (P < 0.0001), but a Diet x Time interaction was not observed. Urinary NTx exhibited no main diet effect, time effect or Diet x Time interaction at weeks 1 or 2. Urinary pH was lower in the LCHP group compared to the HCLF group throughout the study (P < 0.0001). Urinary calcium excretion was higher in the LCHP group and lower in the HCLF group (P < 0.0001) compared to baseline values at all intervals of the study. Urinary phosphorus excretion exhibited a significant diet effect (P < 0.001) and time effect (P < 0.002), while no Diet x Time interaction was observed. Total cholesterol, high-density and low-density lipoprotein cholesterol, and triacylglycerol concentrations did not differ between diets during the study. In conclusion, a LCHP diet appears to stimulate bone loss, while a HCLF diet appears to attenuate bone loss in healthy pre-menopausal women undergoing 12 weeks of weight loss.
Files
  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
 
 28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access 
  Coleman.pdf 6.60 Mb 00:30:33 00:15:42 00:13:45 00:06:52 00:00:35

Browse All Available ETDs by ( Author | Department )

dla home
etds imagebase journals news ereserve special collections
virgnia tech home contact dla university libraries

If you have questions or technical problems, please Contact DLA.