понеделник, 12 май 2008 г.

Therapeutic weight loss techniques

The least intrusive weight loss methods, and those most often recommended by physicians, are adjustments to eating patterns and increased physical exercise. Usually, health professionals will recommend that their overweight patients combine a reduction of the caloric content of the diet with an increase in physical activity.

Other methods of losing weight include use of drugs and supplements that decrease appetite, block fat absorption, or reduce stomach volume. Surgery is another method. Bariatric surgery artificially reduces the size of the stomach, limiting the intake of food energy. Some of these treatments may have serious side-effects.

"Crash Dieting"

A crash diet (also known as "fasting") is where a person willfully restricts themselves of all nourishment (except water) for more than 12 hours. The desired result is to have the body burn fat for energy with the goal of losing a significant amount of weight in a short time. Crash dieting is not the same as flexible intermittent fasting, where dieters fast for 2 days each week and calories are cycled. Generally the weight lost in a crash diet returns when normal eating resumes.

Weight loss industry

In the developed world, there is a substantial market for products which promise to make weight loss easier, quicker, cheaper, more reliable, or less painful. These include books, CDs, cremes, lotions, pills, rings and earrings, body wraps, body belts and other materials, fitness centers, personal coaches, weight loss groups and food products and supplements. US residents in 1992 spent an estimated $30 billion a year on all types of diet programs and products, including diet foods and drinks.

Between $33 billion and $55 billion is spent annually on weight loss products and services, including medical procedures and pharmaceuticals, with weight loss centers garnering between six percent and 12 percent of total annual expenditure. About 70 percent of American's dieting attempts are of a self-help nature. Although often short-lived, these diet fads are a positive trend for this sector as Americans ultimately turn to professionals to help them meet their weight loss goals

Intentional weight loss

Weight loss may refer to the loss of total body mass in an effort to improve fitness, health, and/or appearance.

Therapeutic weight loss, in individuals who are overweight, can decrease the likelihood of developing diseases such as diabetes. Overweight and obese individuals face a greater risk of health conditions such as type 2 diabetes, heart disease, high blood pressure, stroke, osteoarthritis and certain types of cancer. For healthy weight loss, a physician should be consulted to develop a weight loss plan that is tailored to the individual.

Weight loss occurs when an individual is in a state of negative energy balance. When the human body is spending more energy in work and heat than it is gaining from food or other nutritional supplements, it will catabolise stored reserves of fat or muscle.

Although weight loss may involve loss of fat, muscle or fluid, weight loss for the purposes of maintaining health should aim to lose fat while conserving muscle and fluid.[citation needed]

It is not uncommon for people who are already at a medically healthy weight to intentionally lose weight. In some cases it is with the goal of improving athletic performance or to meet weight classifications in a sport. In other cases, the goal is to attain a more attractively shaped body. Being underweight is associated with health risks. Health problems can include difficulty fighting off infection, osteoporosis, decreased muscle strength, trouble regulating body temperature and even increased risk of death.

неделя, 13 април 2008 г.

Blood type diet

Blood type diet

From Wikipedia, the free encyclopedia

The blood type diet is a diet advocated by Peter D'Adamo and outlined in his book Eat Right 4 Your Type. Its basic premise is that ABO blood type is the most important factor in determining a healthy diet. The diet is widely derided by dieticians, physicians, and nutritional scientists as having no scientific basis.

The cornerstone of his theory is D’Adamo’s premise that lectins in foods react differently with each ABO blood type. Throughout his books he cites the works of various biochemists and glycobiologists who have researched blood groups, claiming or implying that their research supports this theory. In his book, Eat Right 4 Your Type, "Lectins: The Diet Connection", and in following chapters, "lectins" which interact with the different ABO type "antigens" are described as incompatible and harmful, therefore the selection of different foods for A, AB, B, and O types to minimize reactions with these lectins.

D'Adamo bases his ideas on the ABO classification of Karl Landsteiner and Jan Janský, and some of the many other tissue surface antigens and classification systems, in particular the Lewis antigen system for ABH secretor status. [2]

The evolutionary theory of blood groups, which is also used by D'Adamo, stems from work by William C. Boyd, an immunochemist and blood type anthropologist who made a worldwide survey of the distribution of blood groups. In his book Genetics and the races of man: An introduction to modern physical anthropology, published in 1950, Boyd describes how by genetic analysis of blood groups, human races are populations that differ according to their alleles. On this basis, Boyd divided the world population into 13 geographically distinct races with slightly different frequency distributions of blood group genes.

D'Adamo groups those thirteen races together by ABO blood group, each type within this group having unique dietary recommendations:

  • Blood group O is believed by D'Adamo to be the hunter, the earliest human blood group. The diet recommends that these supposedly muscular, active people eat a meat-rich diet.
  • Blood group A is called the cultivator by D'Adamo, who believes it to be a more recently evolved blood type, dating back from the dawn of agriculture. The diet recommends that individuals of blood group A eat a diet emphasizing vegetables and free of red meat, a more vegetarian food intake.
  • Blood group B is, according to D'Adamo, the nomad, associated with a strong immune system and a flexible digestive system. The blood type diet claims that people of blood type B are the only ones who can thrive on dairy products.
  • Blood group AB, per D'Adamo, the enigma, the most recently evolved type. In terms of dietary needs, his blood type diet treats this group as an intermediate between blood types A and B.

Criticism

D'Adamo's Blood Type Diet has met with several criticisms. The fundamental criticisms are, for one, that none of his hundreds of citations to others' research on blood groups directly support his claims of differential food tolerances and, secondly, that he provides no comparative clinical trials demonstrating efficacy of his diet.

Evidence

One criticism of D'Adamo's hypotheses and recommendations claims that he provided inadequate evidence. For example, his first book, Eat Right 4 Your Type, published in 1997, contains only a bibliography. Most of his subsequent books, however, have been thoroughly referenced as far as his general theory. However, despite his providing general reasons for the classifications of various foods within his established categories of "beneficials", "neutrals" and "avoids", his specific process for reaching these conclusions of classification remain undocumented.

Although D'Adamo claims there are many ABO specific lectins in foods, this claim is, for a number of his cited cases, unsubstantied by established biochemical research, which has not found differences in how the lectins react with a given human ABO type. A common criticism is that lectins which are preferential for a particular ABO type are not found in foods (except for one or two rare exceptions, e.g. lima bean), and that lectins with ABO specificity are more frequently found in non-food plants or animals.

Another criticism is that there are no clinical trials of the Blood Type Diet. In his first book Eat Right 4 Your Type, D'Adamo mentions being in the eighth year of a 10 year cancer trial, but no results of this trial have ever been published. In his book Arthritis: Fight It With the Blood type Diet, D'Adamo mentions an impending clinical trial of the Blood Type Diet in order to determine its effects on the outcomes of patients with rheumatoid arthritis, but no results of this trial have yet been published.

Blood type evolution

In the article "Genetic of the ABO blood system and its link with the immune system", Luiz C. de Mattos and Haroldo W. Moreira point out that D'Adamo's assertion that the O blood type was the first human blood type requires that the O gene evolved before the A and B genes in the ABO locus. Instead, phylogenetic networks of human and non-human ABO alleles show that the A gene was the first to evolve. The authors argue that, in the evolutionary sense, it would be extraordinary for normal genes (those for types A and B) to have evolved from abnormal genes (for type O).

Yamamoto et al. further note:

Although the O blood type is common in all populations around the world, there is no evidence that the O gene represents the ancestral gene at the ABO locus. Nor is it reasonable to suppose that a defective gene would arise spontaneously and then evolve into normal genes.

In May 2004, Transfusion published a study which concluded that: "Assuming constancy of evolutionary rate, diversification of the representative alleles of the three human ABO lineages (A101, B101, and O02) was estimated at 4.5 to 6 million years ago." This finding declares that ABO did not evolve in the near past, essentially contradicting that which D'Adamo suggests.

Inedia

Inedia

From Wikipedia, the free encyclopedia


Jasmuheen

Jasmuheen (born Ellen Greve) was probably the most famous advocate of Breatharianism during the 1990s. She claimed "I can go for months and months without having anything at all other than a cup of tea. My body runs on a different kind of nourishment."Several interviewers found her house full of food, but she claimed the food was for her husband. In 1999, she volunteered to be monitored closely by the Australian television program 60 Minutes for one week without eating to demonstrate her methods Greve claimed that she failed because on the first day of the test she had been confined in a hotel room near a busy road, saying that the stress and pollution kept her from getting the nutrients she needed from the air. “I asked for fresh air. Seventy percent of my nutrients come from fresh air. I couldn’t even breathe,” she said. On the third day the test moved to a mountainside retreat where she could get plenty of fresh air and live happily. After Greve had fasted for four days, Dr. Berris Wink, president of the Queensland branch of the Australian Medical Association, urged her to stop the test.

According to the doctor, Greve’s pupils were dilated, her speech was slow, she was "quite dehydrated, probably over 10%, getting up to 11%." Towards the end of the test, he said, "Her pulse is about double what it was when she started. The risks if she goes any further are kidney failure. 60 Minutes would be culpable if they encouraged her to continue. She should stop now." The test was stopped. Dr. Wink said, "Unfortunately there are a few people who may believe what she says, and I'm sure it's only a few, but I think it's quite irresponsible for somebody to be trying to encourage others to do something that is so detrimental to their health She challenged the results of the program, saying, "Look, 6,000 people have done this around the world without any problem." [4] Though she claims thousands of followers,mostly in Germany,there is no evidence that any have lived for long periods of time without any food at all.

Jasmuheen was awarded the Bent Spoon Award by Australian Skeptics in 2000 ("presented to the perpetrator of the most preposterous piece of paranormal or pseudoscientific piffle"). She also won the 2000 Ig Nobel Prize for Literature for Living on Light. Jasmuheen claims that their beliefs are based on the writings and "more recent channelled material" of the Count of St Germain. She claims that her DNA has expanded from 2 to 12 strands, to "absorb more hydrogen". When offered $30,000 to prove her claim with a blood test, she said that she didn't understand the relevance

Deaths

The well-publicized deaths of 49-year-old Australian-born Scotland resident Verity Linn, 31-year-old Munich kindergarten teacher Timo Degen, and 53-year-old Melbourne resident Lani Marcia Roslyn Morris, while attempting to enter the Breatharian "diet," have drawn further criticism of the idea.[1][2] Jim Vadim Pesnak, 63, and his wife Eugenia, 60, went to jail for three years on charges of manslaughter for their involvement in the death of Morris. Verity Lynn, the Scottish woman who inadvertently killed herself by choosing the Breatharian "diet" was a nominee for the 1999 Darwin Awards. She "took to the highlands", the article says, "with only a tent and her grit and determination." She died of hypothermia and dehydration, aggravated by lack of food. Jasmuheen claimed that her death was brought on by a psycho-spiritual problem, rather than a physiological one.

Jasmuheen has denied any involvement with the three deaths and claims she cannot be held responsible for the actions of her followers. In reference to the death of Lani Morris, she said that perhaps Morris was "not coming from a place of integrity and did not have the right motivation

Wiley Brooks

Wiley Brooks is a purported breatharian, and founder of the Breatharian Institute of America. He was first introduced to the public in 1981, when he appeared on the TV show That's Incredible!. Wiley has stopped teaching in recent years, so he can "devote 100% of his time on solving the problem as to why he needed to eat some type of food to keep his physical body alive and allow his light body to manifest completely." This comes after much controversy over the years. In 1983 he was allegedly spotted leaving a Santa Cruz 7-Eleven with a Slurpee, hot dog and Twinkies.

He told Colors magazine in 2003 that he periodically breaks his fasting with a Big Mac and Coke, explaining that when he's surrounded by junk culture and foods, consuming them adds balance. On his website Brooks goes on to explain that his future followers must first prepare by combining the junk food diet with the meditative incantation of the five magic fifth-dimensional words which appear on his website.Prospective disciples are asked after some time on this junk food/magic word preparation to revisit his website in order to test if they can feel the magic.[5] He further mentions that those interested can call him on his fifth-dimensional phone number in order to get the correct pronunciation of the five magic words.[5] In case the line is busy prospective recruits are asked to meditate on the five magic words for a few minutes and then try calling again.[5] However he does not explain how anyone can meditate with words they cannot yet pronounce. Wiley Brooks' Breatharian Institute of America charges $15,000,000 US (minimum) to learn how to live without food.[6] This charge is a limited time offer and it is scheduled to go up in November 2007 to 20,000,000 and in January 2008 it will reach 25,000,000 US dollars.[6] A payment plan can be arranged but no refunds are offered currently.[6] In addition all applicants must be pre-qualified by the Breatharian Institute.[7]

Hira Ratan Manek

Hira Ratan Manek (born September 12, 1937) claims that since June 18th, 1995, he has lived exclusively on water, and occasional tea, coffee, and buttermilk. He says sunlight is the key to his health, citing the Jainist Tirthankara Mahavira, ancient Egyptians, Greeks, and Native Americans as his inspiration.

According to his website, three extended periods of his fasting have been observed under control of scientific and medical teams: the first lasting 211 days in 1995-96 in Calicut, India, under the direction of Dr C. K. Ramachandran. During that period he is reported to have lost 41 kg.[14]

The second study lasted 411 days in 2000-2001 in Ahmedabad, India, under the direction of a 21 member team of medical doctors and scientists led by Dr Sudhir Shah and Dr K. K. Shah, a past President of the Indian Medical Association and current Chairman of the Jainist Doctors' Federation. The latter group aims to "Promote scientific research and medical education based on principles of Jainism"[15]. Dr K. K. Shah said "Fasting is a method of curing the meditation of mind and body which has been proved by great jain monks, sanyasis and munis of ancient times. There is a need to propagate these methods during this age of increasing diseases of the body and mind due to overconsumptions and increasing with fasting would help maintain perfection."[16]. Dr Sudhir Shah was also involved in the study of Prahlad Jani.[17]

The paper[18] published by Dr Sudhir Shah makes it clear that dozens of people had access to Hira Ratan Manek during the study and he went on at least one excursion: "Most surprisingly, he had himself climbed the famous Shatrunjay mountain (Palitana hill) on 4.4.01, on 401st day of his legendary fasting along with 500 fellowmen without anybody’s help, within 1.5 Hrs. only". The paper reports that the subject lost 19 kg of weight during the study period. Neither the experiment, as described in the paper, nor the paper itself have been validated by any well-known Western scientific or medical journal.

The third study lasted 130 days in Philadelphia, Pennsylvania, at Thomas Jefferson University and the University of Pennsylvania under the direction of Dr. Andrew Newberg and Dr. George C. Brainard. Dr Sudhir Shah, who led the previous study, acted as an advisor and consultant to the USA team.[19]

However, Dr. Andrew Newberg said that Hira stayed at the University of Pennsylvania only for brain scans on studies of meditation, not his ability to fast indefinitely[citation needed]. Newberg denied ever undertaking the 130-day study.[citation needed]

Buddhism and vegetarianism

Buddhism and vegetarianism

Buddhism, along with Jainism, recognizes that even eating vegetables could contribute to the indirect killing of living beings as animal life is destroyed as farmers plough land. Jainism consequently considers death by starvation as the ultimate practice of non violence, while Buddhism considers extreme self-mortification to be undesirable for attaining enlightenment.

Both Mahayana and Theravada theology generally hold that meat eating in and of itself does not constitute a violation of the Five Precepts which prohibit one from directly harming life. Pali/Sanskrit term for monks and nuns means one who seek alms. However, when monks and nuns who follow the Theravada feed themselves by alms, they must eat whatever leftover foods which are given to them including meat. Exception to this alms rule is when monks and nuns have seen, heard or known that animal(s) have been specifically killed to feed the alm seeker or guest, in which case, consumption of such meat would be karmically negative. This is also followed by lay Buddhists; and is known as the consumption of the 'triply-clean meat' (三净肉 sanjingrou). On the other hand, when lay communities specifically purchase meat for consumption of monks and nuns, permissibility of meat eating differ among different Buddhist sects. Theravada Pali Canon records instances of Buddha eating meat which were specifically purchased for Buddha. This act was deliberately performed by the Buddha to demonstrate that if need be, a Buddhist can bend the rules in times of emergency or inconvenience. Obstinately observing vegetarianism or Buddhist rules in times when you cannot, conflicts with Mahayana philosophy because obstinacy or attachment for anything, is considered to be 'stubborness' (执著 zhizhuo) which will become an obstacle to nirvana or enlightenment. However even then, if one undertakes a vow to be a Buddhist vegetarian, one is expected to follow this vow until it is humanly impossible to continue one's vegetarian diet.

Acceptance of authenticity of the Pali Suttas differ within Mahayana sects and Mahayana sutras do not record Buddha eating meat. While no Mahayana sects consider Pali sutras to be inauthentic, Chinese Buddhist sects tend to consider this particular part of writing in Pali suttas to be false. Japanese Buddhist sects generally accept that Buddha ate meat[1].

Still, both Mahayana and Theravada Buddhists consider that one may practice vegetarianism as part of cultivating Bodhisattvas's paramita. Since Mahayana Buddhists recognise the consumption of meat to be cruel and devoid of compassion, many Mahayana Buddhists are vegetarians. Numbers of Mahayana sutra record Buddha praising the virtue of avoiding meat. However, Tibetan Buddhism believes that tantric practice makes vegetarianism unnecessary. All Japanese Kamakura sects of Buddhism (Zen, Nichiren, Jodo) have relaxed Mahayana vinaya, and as a consequence, do not practice vegetarianism but rather pescetarianism. Chinese Buddhism and part of Korean Buddhism strictly adhere to vegetarianism.

Buddhism and other food considerations

East Asian "Buddhist" cuisine differ from Western vegetarian cuisine in one aspect, that is avoidance of killing plant life. Buddhist vinaya for monks and nuns prohibit harming of plant. Therefore, strictly speaking, no root vegetables (such as potatoes, carrots or onion) are to be used as this will result in death of vegetables. Instead, vegetables such as beans or fruits are used. However, this stricter version of diet is often practiced only on special occasion. Some Mahayana Buddhists in China and Vietnam specifically avoid eating strong-smelling plants, traditionally garlic, Allium chinense, asafoetida, shallot, and Allium victorialis (victory onion or mountain leek), and refer to these as 五荤 'Five Acrid And Strong Smelling Vegetables' or 五辛 'Five Spices' as they tend to excite senses. This is based on teachings found in the Brahma Net Sutra, the Surangama Sutra and the Lankavatara Sutra (chapter 8). In modern times this rule is often interpreted to include other vegetables of the onion genus, as well as coriander.

An example of shōjin-ryōri taken in Kyoto, Japan at the zen temple of Ryuanji.
An example of shōjin-ryōri taken in Kyoto, Japan at the zen temple of Ryuanji.

The food that a strict Buddhist takes, even if he/she is not a vegetarian is also specific. For many Chinese Buddhists, beef and the consumption of large animals and exotic species is avoided. Then there would be the aforementioned sanjingrou rule. One restriction on food that is not known to many is the abstinence from eating animal innards and organs. This is known as 下水 (xiashui), and is a Chinese term and is not to be confused with the Japanese term gesui (sewage).

Alcohol and/or other drugs are also avoided by many Buddhists because of their effects on the mind and "mindfulness". It is part of the Five Precepts which dictate that one is not to consume "addictive materials". The definition of "addictive" depends on each individual but most Buddhists consider alcohol and contraband drugs to be addictive. Stricter Buddhists consider tobacco to be addictive as well.

Common sources for Buddhist foods

Vegetarian restaurant buffet, Taipei, Taiwan. July 2003
Vegetarian restaurant buffet, Taipei, Taiwan. July 2003

Buddhist vegetarian chefs have become extremely creative in imitating meat using prepared wheat gluten, also known as "seitan" or "wheat meat", soy (such as tofu or tempeh), agar, and other plant products. Some of their recipes are the oldest and most-refined meat analogues in the world. Soy and wheat gluten are very versatile materials, because they can be manufactured into various shapes and textures, and they absorb flavourings (including, but not limited to, meat-like flavourings), whilst having very little flavour of their own. With the proper seasonings, they can mimic various kinds of meat quite closely.

Some of these Buddhist vegetarian chefs are in the many monasteries which serve wu hun and mock-meat (also known as 'meat analogues') dishes to the monks and visitors (including non-Buddhists who often stay for a few hours or days, to Buddhists who are not monks, but staying overnight for anywhere up to weeks or months). Many Buddhist restaurants also serve vegetarian, vegan, non-alcoholic, and/or wu hun dishes. Some Buddhists eat vegetarian only once per week or month, or on special occasions such as annual visits to an ancestor's grave. To cater to this type of customer, as well as full-time vegetarians, the menu of a Buddhist vegetarian restaurant usually shows no difference from a typical Chinese or far-Eastern restaurant, except that in recipes originally made to contain meat, a chicken flavoured soy or wheat gluten might be served instead (e.g. "General Tso's chicken" made with flavoured wheat gluten).

сряда, 9 април 2008 г.

Mediterranean diet

Mediterranean diet

From Wikipedia, the free encyclopedia

The Mediterranean diet is a modern nutritional model originally inspired by the traditional dietary patterns of some of the countries of the Mediterranean Basin. The most commonly-understood version of the Mediterranean diet was presented by Dr. Walter Willett of Harvard University's School of Public Health in the mid-1990's. Based on "food patterns typical of Crete, much of the rest of Greece, and southern Italy in the early 1960s", this diet, in addition to "regular physical activity" (e.g. farm labor), emphasizes "abundant plant foods, fresh fruit as the typical daily dessert, olive oil as the principal source of fat, dairy products (principally cheese and yogurt), and fish and poultry consumed in low to moderate amounts, zero to four eggs consumed weekly, red meat consumed in low amounts, and wine consumed in low to moderate amounts". Total fat in this diet is "<> 35%" of calories, with saturated fat at 8% or less of calories. The diet is often cited as beneficial for being low in saturated fat and high in monounsaturated fat and dietary fiber.

This diet is not typical of all part of the Mediterranean basin. In central Italy, for instance, lard and butter are commonly used in cooking, and olive oil is reserved for dressing salads and cooked vegetables. In North Africa, wine was traditionally not consumed by Muslims. In both North Africa and the Levant, sheep's tail fat and rendered butter (samna) are the traditional staple fats. In inland areas before refrigeration, fish was largely unknown, even in Greece and Southern Italy.

Although it was first publicized in 1945 by the American doctor Ancel Keys stationed in Salerno, Italy, the Mediterranean diet failed to gain widespread recognition until the 1990s. It is based on what from the point of view of mainstream nutrition is considered a paradox: that although the people living in Mediterranean countries tend to consume relatively high amounts of fat, they have far lower rates of cardiovascular disease than in countries like the United States, where similar levels of fat consumption are found. A parallel phenomenon is known as the French Paradox.

One of the main explanations is thought to be the large amount of olive oil used in the Mediterranean diet. Unlike the high amount of animal fats typical to the American diet, olive oil lowers cholesterol levels in the blood. It is also known to lower blood sugar levels and blood pressure. Research indicates olive oil prevents peptic ulcers and is effective in treatment of peptic ulcer disease, and may be a factor in preventing cancer. In addition, the consumption of red wine is considered a possible factor, as it contains flavonoids with powerful antioxidant properties.

Michael Pollan in his book "In Defense of Food" suggests the explanation is not any particular nutrient, but the combination of nutrients found in unprocessed food.[citation needed]

Dietary factors may be only part of the reason for the health benefits enjoyed by these cultures. Genetics, lifestyle (notably heavy physical labor), and environment may also be involved.

Although green vegetables, a good source of calcium and iron, as well as goat cheese, a good source of calcium, are dommon in the Mediterranean diet, concerns remain whether the diet provides adequate amounts of all nutrients, particularly calcium and iron.[citation needed]


Medical research

The Seven Countries Study found that Cretan men had exceptionally low death rates from heart disease, despite moderate to high intake of fat. The Cretan diet is similar to other traditional Mediterranean diets: consisting mostly of olive oil, bread, abundant fruit and vegetables, fish, and a moderate amount of dairy foods and wine.

The Lyon Diet Heart Study set out to mimic the Cretan diet, but adopted a pragmatic approach. Realizing that some of the people in the study (all of whom had survived a first heart attack) would be reluctant to move from butter to olive oil, they used a margarine based on rapeseed (canola) oil. The dietary change also included 20% increases in vitamin C rich fruit and bread and decreases in processed and red meat. On this diet, mortality from all causes was reduced by 70%. This study was so successful that the ethics committee decided to stop the study prematurely so that the results of the study could be made available to the public immediately.

Diet food

Diet food

From Wikipedia, the free encyclopedia

Diet food (or dietetic food) refers to any food or drink whose recipe has been altered in some way to make it part of a body modification diet. Although the usual intention is weight loss and change in body type, sometimes the intention is to aid in gaining weight or muscle as in bodybuilding supplements.


Terminology

In addition to diet other words or phrases are used to identify and describe these foods including light or lite, low calorie, low fat, no fat, fat free, no sugar, sugar free, and zero calorie. In some areas use of these terms may be regulated by law. For example in the U.S. a product labeled low fat must not contain more than 3 grams of fat per serving; and to be labeled fat free it must contain less than 0.5 grams of fat per serving.

Process

The process of making a diet version of a food usually requires finding an acceptable low calorie substitute for some high calorie ingredient. This can be as simple as replacing some or all of the food's sugar with a sugar substitute as is common with diet soft drinks such as Coca-Cola. In some snacks, the food may be baked instead of fried thus reducing the calories. In other cases, low fat ingredients may be used as replacements.

Controversy

In diet foods which replace the sugar with lower-calorie substitutes, there is some controversy based around the possibility that the sugar substitutes used to replace sugar are themselves harmful. Even if this question is satisfactorily resolved (which remains unlikely at this time), the question still remains as to whether the benefits of caloric reduction would outweigh the potential harm.

In many low-fat and fat-free foods the fat is replaced with sugar, flour, or other full-calorie ingredients, and the reduction in caloric value is small, if any.