High lifetime exposure to oestrogens is related to higher breast cancer risk before and after menopause. Lower dietary fat intake can correlate with lower oestrogen levels mainly via decreased total energy intake. The influence of a restrictive diet on lowering ovarian steroid levels is well documented, whilst partly decreasing total energy intake by a low fat diet has not been well investigated yet. The influence of various types of fat on ovarian hormone levels also remains unexplored. The role of dietary fat in initiation and development of breast cancer is still controversial; however a trend towards higher oestrogens and breast cancer risk with increasing consumption of total fat, saturated fatty acids intake and polyunsaturated fatty acids n-6 intake can be seen. It is possible that dietary fat intake is a factor that can raise the levels of ovarian steroids but only when accompanied by a positive energy balance.