''Fit for Life'' is a diet and lifestyle book series stemming from the principles of

orthopathy Orthopathy (from the Greek ὀρθός ''orthos'' 'right' and πάθος ''pathos'' 'suffering') or natural hygiene (NH) is a set of alternative medical beliefs and practices originating from the ''Nature Cure'' movement. Proponents claim that f ...

. It is promoted mainly by the American writers Harvey and

Marilyn Diamond Marilyn Diamond is an American author and speaker on the topic of anti-aging and longevity. She is known for advocating a "cleansing" or "detoxification" diet. Career In 1985, with her then husband Harvey Diamond, she co-authored the best-selling ...

. The ''Fit for Life'' book series describes a

fad diet A fad diet is a diet that becomes popular for a short time, similar to fads in fashion, without being a standard dietary recommendation, and often making unreasonable claims for fast weight loss or health improvements. There is no single defini ...

which specifies eating only fruit in the morning, eating predominantly "live" and "high-water-content" food, and, if animal protein is eaten, avoiding combining it with

complex carbohydrates In organic chemistry, a carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where ''m'' may or may ...

. While the diet has been praised for encouraging the consumption of raw fruits and vegetables, several other aspects of the diet have been disputed by dietitians and nutritionists, and the

American Dietetic Association The Academy of Nutrition and Dietetics is a 501(c)(6) trade association in the United States. With over 112,000 members, the association claims to be the largest organization of food and nutrition professionals. It has registered dietitian nutr ...

and the American Academy of Family Physicians list it as a

Description

The diet is based on Diamond's exploration of Herbert M. Shelton theories of

food combining Food combining is a term for a nutritional pseudoscientific approach that advocates specific combinations (or advises against certain combinations) of foods. Some combinations are promoted as central to good health, improved digestion, and weight lo ...

. Both authors claimed to be able to bring about weight loss without the need to count calories or undertake anything more than a reasonable exercise program. In the first version of the program, Diamond claimed that if one eats the foods in the wrong combination they "cause fermentation" in the stomach. This in turn gives rise to the destruction of valuable enzymes and nutrients. Diamond categorized foods into two groups: "dead foods" that "clog" the body, and "living foods" that "cleanse" it. According to Fit for Life principles, dead foods are those that have highly refined or highly processed origins; while living foods are raw fruits and vegetables. The basic points of Fit for Life are as follows: *

Fruits In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particula ...

are best eaten fresh and raw. Where possible they should be eaten alone. * Carbohydrates and

proteins Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

should never be combined in the same meal. * Water dilutes stomach digestive juices and should never be drunk at meals. *

Dairy product Dairy products or milk products, also known as lacticinia, are food products made from (or containing) milk. The most common dairy animals are cow, water buffalo, nanny goat, and ewe. Dairy products include common grocery store food items in th ...

s are considered of limited value and because of their allergic capacity, should seldom, if ever, be eaten. In the 2000s, the Fit for Life system added the Personalized Fit for Life Weight Management Program, which employs proprietary protocols called Biochemical "Analyzation", Metabolic Typing and Genetic Predispositions. The Diamonds claim that these protocols allow the personalization of the diet, which thus customized is effective only for one individual, and can be used for that person's entire life. This version of the diet also puts less emphasis on "live" and "dead" foods, and instead talks of "enzyme deficient foods". The Diamonds posit that enzymes that digest proteins interfere with enzymes that digest carbohydrates, justifying some of the rules above. They also began to sell

nutritional supplement A dietary supplement is a manufactured product intended to supplement one's diet by taking a pill, capsule, tablet, powder, or liquid. A supplement can provide nutrients either extracted from food sources or that are synthetic in order ...

s, advertised as enzyme supplements, many of which are strongly recommended in the newest version of Fit for Life.

Publications and marketing

The diet came to public attention in the mid-1980s with the publication of ''Fit for Life'', a ''

New York Times ''The New York Times'' (''the Times'', ''NYT'', or the Gray Lady) is a daily newspaper based in New York City with a worldwide readership reported in 2020 to comprise a declining 840,000 paid print subscribers, and a growing 6 million paid d ...

'' best seller which sold millions of copies, over 12 million according to Harvey Diamond. Harvey Diamond has also appeared on dozens of television talk shows promoting his theories. In ''Fit for Life II'' (1989) the Diamonds warned against eating artificial food additives such as

hydrogenated vegetable oil Fat hydrogenation is the process of combining fat – typically liquid vegetable oils – with hydrogen, to convert some or all of the unsaturated fat into saturated fat, resulting in a solid or semi-solid fat. Changing the degree of saturation ...

, which at the time was being promoted by the food industry as a healthy alternative to saturated fat.

Tony Robbins Anthony Jay Robbins (né Mahavoric, born February 29, 1960) is an American author, coach, speaker, and philanthropist. He is known for his infomercials, seminars, and self-help books including the books '' Unlimited Power'' and ''Awaken the G ...

promoted the ''Fit for Life'' principles and

veganism Veganism is the practice of abstaining from the use of animal product—particularly in diet—and an associated philosophy that rejects the commodity status of animals. An individual who follows the diet or philosophy is known as a vegan. ...

to increase energy levels in his book ''

Unlimited Power ''Unlimited Power'' is a self-help book by author and motivational speaker Tony Robbins. It was published by Fawcett Columbine (Ballantine Books) in 1986. It was reviewed by ''Publishers Weekly'' and ''Kirkus Reviews, Kirkus''. References

...

''.

Book series

*''Fit for Life'' (1985) - by Harvey and Marilyn Diamond *''Living Health'' (1987) - by Harvey and Marilyn Diamond *''Fit for Life II'' (1989) - by Harvey and Marilyn Diamond *''Fit for Life: A New Beginning'' (2001) - by Harvey Diamond *''Fit for Life Not Fat For Life'' (2003) - by Harvey Diamond *''Living Without Pain'' (2007) - by Harvey Diamond

Additional books by Marilyn Diamond

*''A New Way of Eating from the Fit for Life Kitchen'' (1987) *''The American Vegetarian Cookbook from the Fit for Life Kitchen'' (1990) *''The Fit for Life Cookbook'' (1991) *''Fitonics for Life'' (1996) with Donald Burton Schnell *''Recipes for Life'' (1998) with Lisa Neurith *''Young For Life'' (2013) with Donald Burton Schnell

Controversy

Scientific reception

Health experts and science writers have dismissed the book as

quackery Quackery, often synonymous with health fraud, is the promotion of fraudulent or ignorant medical practices. A quack is a "fraudulent or ignorant pretender to medical skill" or "a person who pretends, professionally or publicly, to have skill, ...

."Fit For Life: Some Notes on the Book and Its Roots"

Quackwatch Quackwatch is a United States-based website, self-described as a "network of people" founded by Stephen Barrett, which aims to "combat health-related frauds, myths, fads, fallacies, and misconduct" and to focus on "quackery-related information th ...

Credentials

The rigor of study underlying Harvey Diamond's credentials have been disputed, which has drawn questions about his competence to write about nutrition, because his doctoral degree came from the

American College of Life Science American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, pe ...

, a non-accredited correspondence school founded in 1982 by T.C. Fry, who did not graduate high school or undergo a formal accreditation process himself. Fit for Life's personalized diet program has been criticized for providing a "Clinical Manual" that is heavily infused with

alternative medicine Alternative medicine is any practice that aims to achieve the healing effects of medicine despite lacking biological plausibility, testability, repeatability, or evidence from clinical trials. Complementary medicine (CM), complementary and alt ...

claims about how the body works, some of which may be scientifically inaccurate or not accepted by conventional medicine.

Clinical trials

Despite the fact that the Fit for Life web site mentioned "clinical trials", many of the proposed principles and benefits of the Fit for Life diet are not supported by citations to any scholarly research, and some of the claims have actually been directly refuted by scientific research. For example, a

dissociated diet Food combining is a term for a nutritional pseudoscientific approach that advocates specific combinations (or advises against certain combinations) of foods. Some combinations are promoted as central to good health, improved digestion, and weight lo ...

as that advertised by Fit for Life is as effective for weight loss as a calorie-restricted diet.

References

External links

Harvey Diamond's official websiteCriticism by James J. Kenney, Ph.D., R.D.
written in 1986)

{{Portal bar, Books, Food, 1980s 1985 non-fiction books Dieting books Fad diets Orthopathy Semi-vegetarianism Vegetarianism in the United States