The purpose of this study is to study the relationships between obesity, hormones and breast cancer in women who have gone through menopause, and those who are still menstruating. The researchers would like to study whether a diet which involves eating for only a certain portion of the day (called a time-restricted diet or TRED), is easy for overweight women to maintain. Participants will be helped by this smartphone application. The researchers also want to study the effect of this TRED on weight control, hormones, and breast tissue. The researchers think that this might be an effective and manageable way to control the bad effects of overweight on health and also to lose weight.