It is an animal product that is manufactured from fat, and higher levels of saturated fat usually lead to higher levels of cholesterol in blood . A high level of cholesterol is associated with heart disease. Dietary fat Body fat, especially gross obesity , is a factor in heart disease and diabetes mellitus. In the 1950s scientists discovered that even people who are not noticeably overweight are more likely to have heart disease if they obtain a large portion of their calories from fat. Although the relationship is statistical, careful studies have confirmed that fat is connected to heart disease and to a reduction in the length of life.
Some scientists think that fat is a factor in other diseases as well, such as breast cancer.
For example, ethnic groups that eat little fatty food throughout their lives often have fewer cases of breast cancer. Significantly, people in Japan eat much less fat than do Americans, and the breast cancer rate in Japan is about a fourth of that in the United States. Furthermore, women from Japanese backgrounds who are raised in the United States have the same high breast cancer rates as other Americans. Thus the proposed link. But controlled studies of Americans find no relationship between dietary fat and breast cancer.