This is a research study to look at the association between weight loss and the menstrual cycle in healthy, overweight, premenopausal women. Participants will be asked to follow a reduced-calorie diet and exercise plan for 3 months.

Two different reduced calorie diet and exercise plans will be compared. One plan changes diet and exercise prescription with the phases of the menstrual cycle, while the other is a standard reduced calorie diet and exercise plan based on MyPyramid.gov website.

Inclusion Criteria:

• Healthy females between the ages of 18-40 (inclusive)
• BMI between 26.5-35.4 kg/m² (inclusive)
• Regular menstrual cycle (28 ± 3 days)
• Weight stable (within ± 3-kg) 2 months prior to study inclusion
• Must use barrier contraception (e.g. male/female condom) for the study's duration
• Must be willing to follow the prescribed diet/exercise plan for the study's duration

Exclusion Criteria:

• On hormonal contraceptives or any other daily use of medications which can make the subject unsuitable for inclusion in the study.
• Any significant health problem (history of cancer, HIV/AIDS, Diabetes, cardiovascular disease, untreated hypothyroidism, etc.)
• Restrictions against participating in cardiovascular exercise and strength training
• Any condition, which in the opinion of the investigator makes the subject unsuitable for inclusion in the study.
• Women who are pregnant, lactating, or planning to become pregnant during the study period