Curves 30/30 Study

Effects of Repeated Short-Term Diets on Weight Loss in Women Participating in the Curves Fitness Program

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT04344821

Acronym

C-30

Enrollment

Registered

2020-04-14

Start date

2009-05-18

Completion date

2012-05-03

Last updated

2020-04-15

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Weight Loss

Brief summary

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.

Detailed description

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.

Interventions

DIETARY_SUPPLEMENTCurves Calcium

Dietary Supplement: Curves Calcium Curves Essential Bio-Available Calcium (providing 800 mg/d of calcium \[as calcium citrate malate and calcium citrate\], 400 IU of Vitamin D, 300 mg/d of magnesium, 4 mg/d of zinc, 2 mg/d of copper, 2 mg/d of manganese, 198 mg/d of potassium, 100 mg/d of trace mineral complex, and 2 mg/d of boron)

DIETARY_SUPPLEMENTPlacebo

Dextrose Placebo

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

HEALTH_SERVICES_RESEARCH

Masking

SINGLE (Investigator)

Masking description

Double (Participant, Investigator)

Intervention model description

Randomized, placebo controlled, repeated measures intervention trial

Eligibility

Sex/Gender

FEMALE

Age

18 Years to 45 Years

Healthy volunteers

Yes

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;

Design outcomes

Primary

Measure	Time frame	Description
Body Composition: Body Fat	Measured prior to supplementation (Pre), and after 1, 2, 3, 4, 5 and 6 months	Changes in body composition (% body fat) obtained via DXA and analyzed by General Linear Model multivariate and univariate analyses with repeated measures and mean change from baseline with 95% confidence intervals (CI's)
Body Composition: Fat Free Mass	Measured prior to supplementation (Pre), and after 1, 2, 3, 4, 5 and 6 months	Changes in body composition (fat free mass) obtained via DXA and analyzed by General Linear Model multivariate and univariate analyses with repeated measures and mean change from baseline with 95% confidence intervals (CI's)
Body Composition: Bone Mass	Measured prior to supplementation (Pre), and after 1, 2, 3, 4, 5 and 6 months	Changes in body composition (bone mass) obtained via DXA and analyzed by General Linear Model multivariate and univariate analyses with repeated measures and mean change from baseline with 95% confidence intervals (CI's)
Body Composition: Fat Mass	Measured prior to supplementation (Pre), and after 1, 2, 3, 4, 5 and 6 months	Changes in body composition (fat mass) obtained via DXA and analyzed by General Linear Model multivariate and univariate analyses with repeated measures and mean change from baseline with 95% confidence intervals (CI's)
Body Composition: Lean Mass	Measured prior to supplementation (Pre), and after 1, 2, 3, 4, 5 and 6 months	Changes in body composition (lean mass) obtained via DXA and analyzed by General Linear Model multivariate and univariate analyses with repeated measures and mean change from baseline with 95% confidence intervals (CI's)
Body Composition: Body Weight	Measured prior to supplementation (Pre), and after 1, 2, 3, 4, 5 and 6 months	Changes in body composition (body weight) obtained via DXA and analyzed by General Linear Model multivariate and univariate analyses with repeated measures and mean change from baseline with 95% confidence intervals (CI's)

Secondary

Measure	Time frame	Description
Cardiac Variable: Resting Electrocardiogram (ECG)	Measured prior to supplementation (Pre), and after 3, and 6 months	Changes in resting ECG obtained via electrodes and analyzed by General Linear Model multivariate and univariate analyses with repeated measures and mean change from baseline with 95% confidence intervals (CI's)
Cardiac Variable: Graded Exercise Test (GXT)	Measured prior to supplementation (Pre), and after 3, and 6 months	Changes in exercise capacity obtained via a treadmill test and analyzed by General Linear Model multivariate and univariate analyses with repeated measures and mean change from baseline with 95% confidence intervals (CI's)
Hemodynamic Variable: Resting Heart Rate (RHR)	Measured prior to supplementation (Pre), and after 1, 2, 3, 4, 5 and 6 months	Changes in resting heart rae (RHR) obtained via a blood pressure meter and analyzed by General Linear Model multivariate and univariate analyses with repeated measures and mean change from baseline with 95% confidence intervals (CI's)
Hemodynamic Variable: Resting Systolic Blood Pressure (SBP)	Measured prior to supplementation (Pre), and after 1, 2, 3, 4, 5 and 6 months	Changes in resting systolic blood pressure (mmHg) analyzed with related resting hemodynamic outcome measures via General Linear Model multivariate and univariate analyses with repeated measures and mean change from baseline with 95% confidence intervals (CI's)
Hemodynamic Variable: Resting Diastolic Blood Pressure (DBP)	Measured prior to supplementation (Pre), and after 1, 2, 3, 4, 5 and 6 months	Changes in resting diastolic blood pressure (mmHg) analyzed with related resting hemodynamic outcome measures via General Linear Model multivariate and univariate analyses with repeated measures and mean change from baseline with 95% confidence intervals (CI's)
Anthropometric Measures: Waist Circumference	Measured prior to supplementation (Pre), and after 1, 2, 3, 4, 5 and 6 months	Changes in waist circumference obtained via tape measure and analyzed by General Linear Model multivariate and univariate analyses with repeated measures and mean change from baseline with 95% confidence intervals (CI's)
Anthropometric Measures: Hip Circumference	Measured prior to supplementation (Pre), and after 1, 2, 3, 4, 5 and 6 months	Changes in hip circumference obtained via tape measure and analyzed by General Linear Model multivariate and univariate analyses with repeated measures and mean change from baseline with 95% confidence intervals (CI's)
Energy Homeostasis: Resting Energy Expenditure (REE)	Measured prior to supplementation (Pre), and after 1, 2, 3, 4, 5 and 6 months	Changes in REE obtained via metabolic cart and expressed in absolute (kcal/d) and relative terms kcals/kg/d) and analyzed by General Linear Model multivariate and univariate analyses with repeated measures and mean change from baseline with 95% confidence intervals (CI's)
Fasting Glucose	Measured prior to supplementation (Pre), and after 1, 2, 3, 4, 5 and 6 months	Changes in glucose obtained via venous blood draws and analyzed by General Linear Model multivariate and univariate analyses with repeated measures and mean change from baseline with 95% confidence intervals (CI's)
Lipid Panel: Cholesterol	Measured prior to supplementation (Pre), and after 1, 2, 3, 4, 5 and 6 months	Changes in cholesterol obtained via venous blood draws and analyzed by General Linear Model multivariate and univariate analyses with repeated measures and mean change from baseline with 95% confidence intervals (CI's)
Lipid Panel: HDL Cholesterol	Measured prior to supplementation (Pre), and after 1, 2, 3, 4, 5 and 6 months	Changes in HDL cholesterol obtained via venous blood draws and analyzed by General Linear Model multivariate and univariate analyses with repeated measures and mean change from baseline with 95% confidence intervals (CI's)
Lipid Panel: Cholesterol to HDL Ratio	Measured prior to supplementation (Pre), and after 1, 2, 3, 4, 5 and 6 months	Changes in cholesterol to HDL ratio obtained via venous blood draws and analyzed by General Linear Model multivariate and univariate analyses with repeated measures and mean change from baseline with 95% confidence intervals (CI's)
Lipid Panel: LDL Cholesterol	Measured prior to supplementation (Pre), and after 1, 2, 3, 4, 5 and 6 months	Changes in LDL cholesterol obtained via venous blood draws and analyzed by General Linear Model multivariate and univariate analyses with repeated measures and mean change from baseline with 95% confidence intervals (CI's)
Lipid Panel: Triglycerides	Measured prior to supplementation (Pre), and after 1, 2, 3, 4, 5 and 6 months	Changes in triglycerides obtained via venous blood draws and analyzed by General Linear Model multivariate and univariate analyses with repeated measures and mean change from baseline with 95% confidence intervals (CI's)
Anthropometric Measures: Waist to Hip Ratio	Measured prior to supplementation (Pre), and after 1, 2, 3, 4, 5 and 6 months	Changes in the ratio of waist to hip (waist/hip circumference) analyzed with related anthropometric outcome measures via General Linear Model multivariate and univariate analyses with repeated measures and mean change from baseline with 95% confidence intervals (CI's)
Energy Homeostasis: Respiratory Exchange Ratio (RER)	Measured prior to supplementation (Pre), and after 1, 2, 3, 4, 5 and 6 months	Changes in RER as an indicator of carbohydrate and fat oxidation analyzed with related resting energy expenditure outcome measures via General Linear Model multivariate and univariate analyses with repeated measures and mean change from baseline with 95% confidence intervals (CI's)
Muscular Strength: 1 Repetition Maximum (1 RM) Bench Press	Measured prior to supplementation (Pre), and after 3, and 6 months	Changes in bench press 1 RM obtained from a bench press test and analyzed by General Linear Model multivariate and univariate analyses with repeated measures and mean change from baseline with 95% confidence intervals (CI's)
Muscular Strength: 1 Repetition Maximum (1 RM) Leg Press	Measured prior to supplementation (Pre), and after 3, and 6 months	Changes in bench press 1 RM obtained from a leg press test and analyzed by General Linear Model multivariate and univariate analyses with repeated measures and mean change from baseline with 95% confidence intervals (CI's)
Muscular Endurance: 80% of 1 Repetition Maximum (1 RM) Bench Press Endurance Test	Measured prior to supplementation (Pre), and after 3, and 6 months	Changes in total repetitions at 80% of 1 RM obtained from a bench press test and analyzed by General Linear Model multivariate and univariate analyses with repeated measures and mean change from baseline with 95% confidence intervals (CI's)
Muscular Endurance: 80% of 1 Repetition Maximum (1 RM) Leg Press Endurance Test	Measured prior to supplementation (Pre), and after 3, and 6 months	Changes in total repetitions at 80% of 1 RM obtained from a leg press test and analyzed by General Linear Model multivariate and univariate analyses with repeated measures and mean change from baseline with 95% confidence intervals (CI's)

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026