Curves 30/30 Study

The purpose of this study is to determine whether following a high carbohydrate/low fat diet or high protein/low fat diet for 30-days several times during six months of participating in the Curves fitness and diet program with or without dietary calcium supplementation promotes stepwise reductions in body weight, improvements in body composition, and/or improvements in markers of fitness and health.

The Curves International fitness and weight loss program has become a very popular means of promoting health and fitness among women. The program involves a 30-minute circuit training program and a weight management program involving periods of moderate caloric restriction (1,200 to 1,600 calories per day) followed by short periods of higher caloric intake (2,600 calories per day). The program is designed to promote a gradual reduction in body fat while increasing strength and muscle mass/tone. Researchers in the Exercise \& Sport Nutrition Laboratory (ESNL) at Texas A\&M University have conducted an extensive study on the effectiveness and safety of the Curves fitness and diet program. Results of this initial study have shown that the program promotes weight loss, improves markers of health, and improves fitness. However, we feel that the program may be even more effective with some additional nutritional interventions. Calcium has been shown to slow bone loss and more recently has been found to help promote fat loss. If this is the case, supplementing the diet with calcium may promote greater benefits in women participating in the Curves fitness and diet program. The purpose of this study is to determine whether following a high carbohydrate/low fat diet or high protein/low fat diet for 30-days several times during six months of participating in the Curves fitness and diet program with or without dietary calcium supplementation promotes stepwise reductions in body weight, improvements in body composition, and/or improvements in markers of fitness and health.

Eligibility Criteria:
Inclusion Criteria:

* Participant is female;
* Participant is post-menopausal;
* Participant is between the ages of 18 and 45;
* Participant is sedentary, overweight (BMI \> 27) and post-menopausal;

Exclusion Criteria:

* Participant has any metabolic disorders including known electrolyte abnormalities, heart disease, arrhythmias, diabetes, or thyroid disease;
* Participant has a history of hypertension, hepatorenal, musculoskeletal, autoimmune or neurological disease;
* Participant is taking thyroid, hyperlipidemic, hypoglycemic, anti-hypertensive or androgenic medications;
* Participant has taken ergogenic levels of nutritional supplements that may affect muscle mass (i.e., creatine, HMB, etc.), anabolic/catabolic hormone levels (i.e., androstenedione, DHEA, etc.) or weight loss (i.e., ephedra, thermogenics, etc.) within three months prior to the start of the study;
* Participant is consistently taking 500 mg or more of a Calcium supplement per day;
* Participant is receiving Hormone Replacement Therapy (HRT);
* Participant is involved in a planned exercise program within 3 - 6 months prior to the start of the study;
* Participant has lost \> 20 lbs. within the last 3 - 6 months;