Abstract: A treatment for obesity and overweight comprises administering a vitamin D analog. The analog effectively inhibits an increase in body fat to animals at risk and decreases the basal fat content of animals. The treatment has a positive effect on the lean body component such that while there is an overall decrease in body weight, there is also a decrease in percent body fat. This decrease can be proportionally greater than the overall decrease in body weight. In addition, the treatment has a positive effect on bone turnover and osteogenesis making the vitamin D analog a beneficial treatment for the symptoms of menopause. Various exemplary embodiments of the treatment use the 2-alkylidene derivatives of vitamin D3, such as the 2-alkylidene-19-nor derivatives in both the R and S configurations at carbon-20.