How do height, weight and body fat distribution affect the age at menarche?
There is a trend towards an earlier age at menarche among girls living in industrialized countries. Taller, heavier girls generally start menstruating earlier than shorter, lighter girls. In addition, the distribution of fat on a girl’s body is related to the levels of hormones circulating in her body and may affect her age at menarche. Girls with fat localized around their hips (pear shaped), may have an earlier menarche than girls with abdominal fat (apple shaped). However, girls with abdominal fat are more likely to be obese and have higher levels of another hormone called insulin. Increases in insulin and growth hormone influence the levels of insulin-like growth factor (IGF-1), which may promote cancer in breast tissue. Height, weight and the distribution of body fat are influenced by heredity. However, diet and exercise behaviors that help maintain healthy weight may prevent changes in hormone levels that could promote the development of breast cancer. How might childhood diet in
