Effect of Diet Composition on Weight Change and Metabolic Parameters
Effect of Diet Composition on Weight Change and Metabolic Parameters
This study will assess the effect of high protein (HP) and high carbohydrate (HC) diets on
 weight loss and other metabolic parameters.

 Rationale: The prevalence of obesity is on the rise in the US. The health hazards of obesity
 have been well established. The detrimental effects of obesity on cardiovascular, metabolic
 and psychological parameters as well as the excess cost to the national health budget are
 astounding. One way of treatment and prevention of obesity has been the use of diet and
 exercise. In the absence of well-established superiority of one diet over another, different
 scientifically unproven diets are in common use. A palatable diet providing satiety as well
 as all essential nutrients may go a long way in treating over-weight individuals. Another
 factor has been the long-term adherence to such weight loss regimens, which in general have
 been poor. Protein diets have been known to provide greater satiety and reduced energy intake
 than carbohydrate diets, but definite long-term studies are sparse. For this study the
 investigators will recruit and study 24 normal, pre-menopausal obese women (12 on HP diet and
 12 on HC diet), and compare their weight loss and changes in metabolic parameters between the
 two diets.
Population: Recruit and study 24 pre-menopausal women with the following inclusion criteria:

 Age range 20 yrs to 50 yrs, BMI > 30 kg/m2 to < 55 kg/m2 Fasting glucose < 110 mg/dl and 120
 minute OGTT < 170 mg/dl glucose Design: The study is designed to determine the follow

 To compare the effects of high protein (HP) versus high carbohydrate (HC) diet during energy
 restriction on weight loss, body composition (lean and fat body mass) and bone mineral
 density in a free living out patient setting.

 To assess the effects of HP versus HC diets on metabolic parameters including insulin
 sensitivity, protein and muscle break down, lipoprotein metabolism and basal metabolic rate.

 Procedures: SCREENING VISIT 1:Individuals fulfilling the inclusion and exclusion criteria
 will be invited for the first screening visit (VS1). A brief study overview will be given
 along with a brief history and physical examination, height and weight measurements and blood
 drawn for chemistry profile and and Oral Glucose Tolerance Test (OGTT) to determine normal
 glucose handling.

 SCREENING VISIT 2 (VS2):Individuals fulfilling all the criteria will be contacted and invited
 for a second screening visit (VS2). Block food frequency questionnaire to assess baseline
 dietary profile will be given along with a pre-study orientation with the help of a
 nutritionist.

 SCREENING VISIT 3 (VS3): At the final screening visit (VS3) the food diary will be reviewed.
 Individuals will be randomized into one of the two diet groups using a randomization table.
 Participants will be asked to participate in the additional studies of euglycemic
 hyperinsulinemic clamp and indirect calorimetry.

 Study participants will either follow a HP or a HC diet for 6 months, where all food is
 supplied to them. Randomization will be performed using a randomization table. HP diet will
 be based on 30% Kcals from protein, 40% Kcals from carbohydrate (CHO) and 30% Kcals from fat.
 In contrast, HC diet will comprise 15% Kcals from protein, 55% Kcals from CHO and 30% Kcals
 from fat. Subjects will come in weekly for their food pick up and weight checks.
Inclusion Criteria:

 -  Age range 20 yrs to 50 yrs,

 -  BMI > 30 kg/m2 to < 55 kg/m2

 -  Fasting glucose < 110 mg/dl and 120 minute OGTT < 170 mg/dl glucose