This article is from the Diet FAQ, by Claudia McCreary firstname.lastname@example.org with numerous contributions by others.
There is strong evidence that the high levels of fat consumed by most
Americans (and members of other westernized cultures) cause, or are a
contributing factor in, diseases such as gallbladder disease, cancer, and
diabetes. High levels of saturated fats, which are found in animal fats,
high-fat dairy foods, tropical oils, and hydrogenated (solidified) vegetable
oils, raise your cholesterol level and promote heart disease and strokes.
The "typical" American diet gets more than 40% of its calories from fat,
with the remaining calories coming from protein and carbohydrates. The
American Heart Association, the National Academy of Science, the American
Cancer Society, and many other groups and nutrition boards across the
country recommend a diet in which a maximum of 30% of calories come from fat
(no more than 10% of total calories from saturated fats), 55-65% calories
come from carbohydrates, and 10-15% of calories are provided by proteins.
A growing body of authorities (Pritikin, McDougall, Ornish, et al.) suggest
that even lower levels of fat (10-20% of total calories) are much better
than 30%, and can actually reverse existing heart disease. Dr. Dean Ornish,
for example, recommends a 10% fat vegetarian diet of fresh fruits and
vegetables, whole grains, and legumes (peas and beans); nonfat dairy
products and egg whites are also allowed. Alcohol (which suppresses the
body's ability to burn fat) and processed sugars (which can trigger food
cravings in many people) are discouraged.
From a weight loss standpoint, a low-fat diet is ideal because it minimizes
the amount of fat that your body has to store in the first place. Excess
dietary fat can be directly stored by your body, no conversion needed (so
perhaps there's some truth in the adage, "Cheesecake goes straight to my
hips"). Proteins and carbohydrates, on the other hand, are usually burned up
immediately rather than being stored. They can be converted to fat if
they're present in sufficient quantities, but that's quite a bit of work for