According to the USDA, a low-fat diet as the name implies is a diet that consists of little fat, especially saturated fat

Saturated fat

Saturated fat is fat that consists of triglycerides containing only saturated fatty acids. Saturated fatty acids have no double bonds between the individual carbon atoms of the fatty acid chain. That is, the chain of carbon atoms is fully "saturated" with hydrogen atoms...

 and cholesterol

Cholesterol

Cholesterol is a complex isoprenoid. Specifically, it is a waxy steroid of fat that is produced in the liver or intestines. It is used to produce hormones and cell membranes and is transported in the blood plasma of all mammals. It is an essential structural component of mammalian cell membranes...

, which are thought to lead to increased blood cholesterol levels and heart attack. It is important to know that dietary fat is needed for good health, as fats supply energy and fatty acids, in addition to supplying fat-soluble vitamins like A, D, E, and K.

In recent years the exact health benefits of a low-fat diet have been debated. A 2006 study published by the Journal of the American Medical Association

Journal of the American Medical Association

The Journal of the American Medical Association is a weekly, peer-reviewed, medical journal, published by the American Medical Association. Beginning in July 2011, the editor in chief will be Howard C. Bauchner, vice chairman of pediatrics at Boston University’s School of Medicine, replacing ...

 argued that a low-fat diet did not reduce the incidence of breast cancer. However, this study was criticized by several epidemiologists for its lack of validity (see "Criticisms" in the Women's Health Initiative

Women's Health Initiative

The Women's Health Initiative was initiated by the U.S. National Institutes of Health in 1991. The objective of this women's health research initiative was to conduct medical research into some of the major health problems of older women...

 article). Recently, the Nurses' Health Study

Nurses' Health Study

The Nurses Health Study, established in 1976 by Dr. Frank Speizer, and the Nurses' Health Study II, established in 1989 by Dr. Walter Willett, are the most definitive long-term epidemiological studies conducted to date on older women's health. The study has followed 121,700 female registered...

 from the Harvard School of Public Health

Harvard School of Public Health

The Harvard School of Public Health is one of the professional graduate schools of Harvard University, located in the Longwood Area of the Boston, Massachusetts neighborhood of Mission Hill, which is next to Harvard Medical School. HSPH is considered a significant school focusing on health in the...

 reported from a Dietary Approaches to Stop Hypertension

Dietary Approaches to Stop Hypertension

The DASH diet is a diet promoted by the National Heart, Lung, and Blood Institute to control hypertension...

 (DASH), and found that a diet "with high intake of fruits, vegetables, and whole grains, moderate intake of legumes, nuts, and low-fat dairy products, and low intake of red and processed meats and sodium, was significantly associated with lower risk of coronary heart disease

Coronary heart disease

Coronary artery disease is the end result of the accumulation of atheromatous plaques within the walls of the coronary arteries that supply the myocardium with oxygen and nutrients. It is sometimes also called coronary heart disease...

 and stroke

Stroke

A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...

 in women." A 2002 Cochrane Review found low-fat diets to be no more effective than other weight loss diets in achieving lasting weight loss, two newer studies concluding the same, published 2008.

Plant-based diets

Doctors Dean Ornish

Dean Ornish

Dean Michael Ornish, M.D., is president and founder of the nonprofit Preventive Medicine Research Institute in Sausalito, California, as well as Clinical Professor of Medicine at the University of California, San Francisco....

, T. Colin Campbell

T. Colin Campbell

T. Colin Campbell is an American biochemist who specializes in the effects of nutrition on long-term health. He is the Jacob Gould Schurman Professor Emeritus of Nutritional Biochemistry at Cornell University, and the author of over 300 research papers...

, John A. McDougall

John A. McDougall

John A. McDougall, M.D., is an American physician and author whose philosophy is that degenerative disease can be prevented and treated with a plant-based diet of whole, unprocessed, low-fat foods, especially starches such as potatoes, rice, and beans, and which excludes all animal foods and added...

, Caldwell Esselstyn

Caldwell Esselstyn

Caldwell Blakeman Esselstyn Jr., M.D., is an American physician, author, and former Olympic rowing champion.-Biography:...

 and Neal D. Barnard

Neal D. Barnard

Neal D. Barnard is an American physician, author, clinical researcher, and founding president of the Physicians Committee for Responsible Medicine , an international network of physicians, scientists, and laypeople who promote preventive medicine, conduct clinical research, and promote higher...

 claim that high animal fat and protein diets, such as the standard American diet, are detrimental to health. They also state that a lifestyle change incorporating a low-fat vegan diet

Veganism

Veganism is the practice of eliminating the use of animal products. Ethical vegans reject the commodity status of animals and the use of animal products for any purpose, while dietary vegans or strict vegetarians eliminate them from their diet only...

 could not only prevent various degenerative disease

Degenerative disease

A degenerative disease, also called neurodegenerative disease, is a disease in which the function or structure of the affected tissues or organs will progressively deteriorate over time, whether due to normal bodily wear or lifestyle choices such as exercise or eating habits...

s, such as coronary artery disease, but reverse them.