Sign Up Today!
Glycemic index does not predict an individual's glycemic response to a food, but can be used as a tool to assess the insulin response burden of a food, averaged across a studied population. Individual responses vary greatly. The glycemic index is usually applied in the context of the quantity of the food and the amount of carbohydrate in the food that is actually consumed.
A related measure, the glycemic load GL ,  factors this in by multiplying the glycemic index of the food in question by the carbohydrate content of the actual serving. Watermelon has a high glycemic index, but a low glycemic load for the quantity typically consumed. GI tables are available that list many types of foods and their GIs.
Some tables also include the serving size and the glycemic load of the food per serving. A practical limitation of the glycemic index is that it does not measure insulin production due to rises in blood sugar.
As a result, two foods could have the same glycemic index, but produce different amounts of insulin. Likewise, two foods could have the same glycemic load, but cause different insulin responses. Furthermore, both the glycemic index and glycemic load measurements are defined by the carbohydrate content of food. For some food comparisons, the " insulin index " may be more useful. More importantly, the glycemic response is different from one person to another, and also in the same person from day to day, depending on blood glucose levels, insulin resistance , and other factors.
The glycemic index only indicates the impact on glucose level two hours after eating the food. People with diabetes have elevated levels for four hours or longer after eating certain foods. Foods with carbohydrates that break down quickly during digestion and release glucose rapidly into the bloodstream tend to have a high GI; foods with carbohydrates that break down more slowly, releasing glucose more gradually into the bloodstream, tend to have a low GI.
The concept was developed by Dr. Jenkins and colleagues  in — at the University of Toronto in their research to find out which foods were best for people with diabetes. A lower glycemic index suggests slower rates of digestion and absorption of the foods' carbohydrates and can also indicate greater extraction from the liver and periphery of the products of carbohydrate digestion.
A lower glycemic response usually equates to a lower insulin demand but not always, and can improve long-term blood glucose control  and blood lipids. The insulin index is also useful for providing a direct measure of the insulin response to a food. The glycemic index of a food is defined as the incremental area under the two-hour blood glucose response curve AUC following a hour fast and ingestion of a food with a certain quantity of available carbohydrate usually 50 g. The AUC of the test food is divided by the AUC of the standard either glucose or white bread, giving two different definitions and multiplied by The average GI value is calculated from data collected in 10 human subjects.
Both the standard and test food must contain an equal amount of available carbohydrate. The result gives a relative ranking for each tested food. The current validated methods use glucose as the reference food, giving it a glycemic index value of by definition. This has the advantages of being universal and producing maximum GI values of approximately For people whose staple carbohydrate source is white bread, this has the advantage of conveying directly whether replacement of the dietary staple with a different food would result in faster or slower blood glucose response.
A disadvantage with this system is that the reference food is not well-defined, because there is no universal standard for the carbohydrate content of white bread. GI values can be interpreted intuitively as percentages on an absolute scale and are commonly interpreted as follows:. A low-GI food will cause blood glucose levels to increase more slowly and steadily, which leads to more suitable postprandial after meal blood glucose readings.
A high-GI food causes a more rapid rise in blood glucose level and is suitable for energy recovery after exercise or for a person experiencing hypoglycemia. The glycemic effect of foods depends on a number of factors, such as the type of starch amylose versus amylopectin , physical entrapment of the starch molecules within the food, fat and protein content of the food and organic acids or their salts in the meal — adding vinegar , for example, will lower the GI.
In general, coarse, grainy breads with higher amounts of fiber have a lower GI value than white breads. While adding fat or protein will lower the glycemic response to a meal, the relative differences remain.
That is, with or without additions, there is still a higher blood glucose curve after a high-GI bread than after a low-GI bread such as pumpernickel. Fruits and vegetables tend to have a low glycemic index.
The glycemic index can be applied only to foods where the test relies on subjects consuming an amount of food containing 50 g of available carbohydrate. Carrots were originally and incorrectly reported as having a high GI.
This has been refuted by brewing industry professionals, who say that all maltose sugar is consumed in the brewing process and that packaged beer has little to no maltose present. Dietary replacement of saturated fats by carbohydrates with a low glycemic index may be beneficial for weight control , whereas substitution with refined, high glycemic index carbohydrates is not.
Several lines of recent  scientific evidence have shown that individuals who followed a low-GI diet over many years were at a significantly lower risk for developing both type 2 diabetes , coronary heart disease , and age-related macular degeneration than others. Postprandial hyperglycemia is a risk factor associated with diabetes. A study shows that it also presents an increased risk for atherosclerosis in the non-diabetic population  and that high GI diets, high blood-sugar levels more generally,  and diabetes  are related to kidney disease as well.
Conversely, there are areas such as Peru and Asia where people eat high-glycemic index foods such as potatoes and high-GI rice without a high level of obesity or diabetes. A study from the University of Sydney in Australia suggests that having a breakfast of white bread and sugar-rich cereals, over time, can make a person susceptible to diabetes, heart disease, and even cancer.
The American Diabetes Association supports glycemic index but warns that the total amount of carbohydrate in the food is still the strongest and most important indicator, and that everyone should make their own custom method that works best for them. Those with diets containing fish or poultry may define meat only as mammalian flesh and may identify with vegetarianism. The term "vegetarian" has been in use since sometime before the so far first discovered written use in to refer to what was previously described as a vegetable regimen or diet, for example in print in India is a strange country.
People do not kill any living creatures, do not keep pigs and fowl, and do not sell live cattle. The earliest record of vegetarianism comes from Indus Valley Civilization as early as the 7th century BCE,  inculcating tolerance towards all living beings. The Orphics , a religious movement spreading in Greece at that time, also practiced and promoted vegetarianism. Vegetarianism was also practiced about six centuries later in another instance 30 BCE — 50 CE in the northern Thracian region by the Moesi tribe who inhabited present-day Serbia and Bulgaria , feeding themselves on honey, milk, and cheese.
In Indian culture, vegetarianism has been closely connected with the attitude of nonviolence towards animals called ahimsa in India for millennia and was promoted by religious groups and philosophers. Following the Christianization of the Roman Empire in late antiquity, vegetarianism practically disappeared from Europe, as it did elsewhere, except in India.
In , the first Vegetarian Society was founded in the United Kingdom;  Germany, the Netherlands, and other countries followed. In , the vegetarian colony Nueva Germania was founded in Paraguay , though its vegetarian aspect would prove short-lived.
In the Western world, the popularity of vegetarianism grew during the 20th century as a result of nutritional, ethical, and—more recently—environmental and economic concerns. Within the " ovo- " groups, there are many who refuse to consume fertilized eggs with balut being an extreme example ; however, such distinction is typically not specifically addressed.
Some vegetarians also avoid products that may use animal ingredients not included in their labels or which use animal products in their manufacturing. For example, sugars that are whitened with bone char , cheeses that use animal rennet enzymes from animal stomach lining , gelatin derived from the collagen inside animals' skin, bones, and connective tissue , some cane sugar but not beet sugar and beverages such as apple juice and alcohol clarified with gelatin or crushed shellfish and sturgeon , while other vegetarians are unaware of, or do not mind, such ingredients.
Individuals sometimes label themselves "vegetarian" while practicing a semi-vegetarian diet,    as some dictionary definitions describe vegetarianism as sometimes including the consumption of fish,  or only include mammalian flesh as part of their definition of meat,   while other definitions exclude fish and all animal flesh.
Semi-vegetarianism is contested by vegetarian groups, such as the Vegetarian Society , which states that vegetarianism excludes all animal flesh. Dietary Guidelines for Americans, — A report issued by the U.
Department of Agriculture and the U. Department of Health and Human Services . Studies on the health effects of vegetarian diets observe heterogeneous effects on mortality. One review found a decreased overall risk of all cause mortality, cancer except breast and cardiovascular disease;  however, a meta-analysis found lower risk for ischemic heart disease and cancer but no effect on overall mortality or cerebrovascular disease.
Vegetarian diets have been shown to prevent and treat gallstones, cardiovascular disease, rheumatoid arthritis, dementia, diverticular disease, renal disease, hypertension, osteoporosis, cancer, and diabetes. A vegetarian diet which is poorly planned can lead to hyperhomocysteinemia and platelet disorders; this risk may be offset by ensuring sufficient consumption of vitamin B 12 and polyunsaturated fatty acids.
The Academy of Nutrition and Dietetics and Dietitians of Canada have stated that at all stages of life, a properly planned vegetarian diet is "healthful, nutritionally adequate, and provides health benefits in the prevention and treatment of certain diseases". Rates of self-reported Seventh-day Adventists SDA were less than half of those of the general population, and, among SDA, vegetarians had lower rates of diabetes than non-vegetarians.
Among possible explanations for a protective effect of vegetarian diet are the Lower BMI of vegetarians and higher fiber intake, both of which improve insulin sensitivity. The relationship between vegetarian diet and bone health remains unclear. According to some studies, a vegetarian lifestyle can be associated with vitamin B 12 deficiency and low bone mineral density.
The China-Cornell-Oxford Project ,  a year study conducted by Cornell University , the University of Oxford , and the government of China has established a correlation between the consumption of animal products and a variety of chronic illnesses, such as coronary heart disease , diabetes , and cancers of the breast , prostate and bowel see The China Study.
A British study of almost 10, men found that those who gave up meat were almost twice as likely to suffer from depression as people on a conventional balanced diet. The study found that the committed vegetarians studied had a higher average depression score compared to others.
A vegetarian diet may help reduce the risk of Alzheimer's disease, as the most important dietary link to Alzheimer's disease appears to be meat consumption, with eggs and high-fat dairy also contributing. Western vegetarian diets are typically high in carotenoids , but relatively low in omega-3 fatty acids and vitamin B Protein intake in vegetarian diets is lower than in meat diets but can meet the daily requirements for most people.
Proteins are composed of amino acids , and a common concern with protein acquired from vegetable sources is an adequate intake of the essential amino acids , which cannot be synthesised by the human body.
While dairy and egg products provide complete sources for ovo-lacto vegetarian , several vegetable sources have significant amounts of all eight types of essential amino acids, including lupin beans , soy ,  hempseed , chia seed ,  amaranth ,  buckwheat ,  pumpkin seeds  spirulina ,  pistachios ,  and quinoa.
A study found a varied intake of such sources can be adequate. Vegetarian diets typically contain similar levels of iron to non-vegetarian diets, but this has lower bioavailability than iron from meat sources, and its absorption can sometimes be inhibited by other dietary constituents. However, the American Dietetic Association states that iron deficiency is no more common in vegetarians than non-vegetarians adult males are rarely iron deficient ; iron deficiency anaemia is rare no matter the diet.
According to the United States National Institutes of Health , vitamin B 12 is not generally present in plants and is naturally found in foods of animal origin.
The recommended dietary allowance of B 12 in the United States is, per day, 0. Plant-based, or vegetarian, sources of Omega 3 fatty acids include soy , walnuts , pumpkin seeds, canola oil , kiwifruit , hempseed , algae , chia seed , flaxseed , echium seed and leafy vegetables such as lettuce, spinach , cabbage and purslane. Purslane contains more Omega 3 than any other known leafy green.
Olives and olive oil are another important plant source of unsaturated fatty acids. Plant foods can provide alpha-linolenic acid which the human body uses to synthesize the long-chain n-3 fatty acids EPA and DHA. While the health effects of low levels of EPA and DHA are unknown, it is unlikely that supplementation with alpha-linolenic acid will significantly increase levels. Calcium intake in vegetarians and vegans can be similar to non-vegetarians, as long as the diet is properly planned.
Non-dairy milks that are fortified with calcium, such as soymilk and almond milk can also contribute a significant amount of calcium in the diet. Vitamin D needs can be met via the human body's own generation upon sufficient and sensible exposure to ultraviolet UV light in sunlight.
Vitamin D 2 , or ergocalciferol is found in fungus except alfalfa which is a plantae and created from viosterol , which in turn is created when ultraviolet light activates ergosterol which is found in fungi and named as a sterol from ergot. Any UV -irradiated fungus including yeast form vitamin D 2.
Claims have been made that a normal serving approx. There have been many comparative and statistical studies of the relationship between diet and longevity, including vegetarianism and longevity. A metastudy combined data from five studies from western countries. Regular meat eaters had the base mortality rate of 1. The study reported the numbers of deaths in each category, and expected error ranges for each ratio, and adjustments made to the data.
However, the "lower mortality was due largely to the relatively low prevalence of smoking in these [vegetarian] cohorts". Out of the major causes of death studied, only one difference in mortality rate was attributed to the difference in diet, as the conclusion states: In Mortality in British vegetarians ,  a similar conclusion is drawn:. British vegetarians have low mortality compared with the general population. Their death rates are similar to those of comparable non-vegetarians, suggesting that much of this benefit may be attributed to non-dietary lifestyle factors such as a low prevalence of smoking and a generally high socio-economic status, or to aspects of the diet other than the avoidance of meat and fish.
The Adventist Health Studies is ongoing research that documents the life expectancy in Seventh-day Adventists. This is the only study among others with similar methodology which had favourable indication for vegetarianism. The researchers found that a combination of different lifestyle choices could influence life expectancy by as much as 10 years. The researchers concluded that "the life expectancies of California Adventist men and women are higher than those of any other well-described natural population" at The life expectancy of California Adventists surviving to age 30 was The Adventist health study is again incorporated into a metastudy titled "Does low meat consumption increase life expectancy in humans?
Statistical studies, such as comparing life expectancy with regional areas and local diets in Europe also have found life expectancy considerably greater in southern France, where a low meat, high plant Mediterranean diet is common, than northern France, where a diet with high meat content is more common. A study by the Institute of Preventive and Clinical Medicine, and Institute of Physiological Chemistry looked at a group of 19 vegetarians lacto-ovo and used as a comparison a group of 19 omnivorous subjects recruited from the same region.
The study found that this group of vegetarians lacto-ovo have a significantly higher amount of plasma carboxymethyllysine and advanced glycation endproducts AGEs compared to this group of non-vegetarians. According to studies by the Permanente Journal and the National Institute for Health NIH , vegetarian diets are affordable and can help reduce health risks like high blood pressure, cardiovascular disease, and cholesterol levels.
A plant based diet has the potential to lower the risk of heart disease as well as reducing the amount of medications prescribed in instances of chronic illness. A change to a plant based diet, or vegetarianism, has had dramatic positive effects on the health of patients with chronic illnesses, significantly more than exercise alone . Vegetarian diets have been studied to see whether they are of benefit in treating arthritis , but no good supporting evidence has been found.
Certain alternative medicines , such as Ayurveda and Siddha , prescribe a vegetarian diet as a normal procedure. Maya Tiwari notes that Ayurveda recommends small portions of meat for some people, though "the rules of hunting and killing the animal, practiced by the native peoples, were very specific and detailed". Now that such methods of hunting and killing are not observed, she does not recommend the use of "any animal meat as food, not even for the Vata types".
The human digestive system is omnivorous , capable of consuming a wide variety of plant and animal material. The American Dietetic Association has presented evidence that vegetarian diets may be more common among adolescents with eating disorders. At the same time the association cautions however, that the adoption of a vegetarian diet may not necessarily lead to eating disorders, rather that "vegetarian diets may be selected to camouflage an existing eating disorder".
Vegetarianism is associated with increased risk of depression, anxiety, and somatoform disorder, although causality cannot be established. Various ethical reasons have been suggested for choosing vegetarianism, usually predicated on the interests of non-human animals.
In many societies, controversy and debate have arisen over the ethics of eating animals. Some people, while not vegetarians, refuse to eat the flesh of certain animals due to cultural taboo , such as cats, dogs, horses or rabbits.
Others support meat eating for scientific, nutritional and cultural reasons, including religious ones. Some meat eaters abstain from the meat of animals reared in particular ways, such as factory farms , or avoid certain meats, such as veal or foie gras.
Some people follow vegetarian or vegan diets not because of moral concerns involving the raising or consumption of animals in general, but because of concerns about the specific treatment and practises involved in the raising and slaughter of animals, i.
Others still avoid meat because meat production is claimed to place a greater burden on the environment than production of an equivalent amount of plant protein. Ethical objections based on consideration for animals are generally divided into opposition to the act of killing in general, and opposition to certain agricultural practices surrounding the production of meat. Princeton University professor and animal rights activist Peter Singer believes that if alternative means of survival exist, one ought to choose the option that does not cause unnecessary harm to animals.
Most ethical vegetarians argue that the same reasons exist against killing animals in the flesh to eat as against killing humans to eat, especially humans with cognitive abilities equal or lesser than the animals in question. Singer, in his book Animal Liberation , listed possible qualities of sentience in non-human creatures that gave such creatures the scope to be considered under utilitarian ethics , and this has been widely referenced by animal rights campaigners and vegetarians.
Ethical vegetarians also believe that killing an animal, like killing a human, especially one who has equal or lesser cognitive abilities than the animals in question, can only be justified in extreme circumstances and that consuming a living creature for its enjoyable taste, convenience, or nutrition value is not a sufficient cause.
Another common view is that humans are morally conscious of their behaviour in a way other animals are not, and therefore subject to higher standards. McMahan stated that cognitively disabled human do not possess the same rights as non-disabled humans. While mentally disabled people were in the past often treated with extreme brutality, with the progression of morality most people understand that the rights of the cognitively disabled still include a right to life and kind treatment.
Increasingly, as moral philosophy progresses further, people understand that, outside of survival situations, denying the right to life to animals with equal or greater cognitive abilities than mentally disabled humans is an arbitrary, discriminatory practice based on habit and desire as opposed to logic. Opponents of ethical vegetarianism argue that animals are not moral equals to humans and so consider the comparison of eating livestock with killing people to be fallacious.
This view does not excuse cruelty, but maintains that animals do not possess the rights a human has. One of the main differences between a vegan and a typical vegetarian diet is the avoidance of both eggs and dairy products such as milk, cheese, butter and yogurt.
Ethical vegans do not consume dairy or eggs because they state that their production causes the animal suffering or a premature death. To produce milk from dairy cattle , calves are separated from their mothers soon after birth and slaughtered or fed milk replacer in order to retain the cows milk for human consumption. A dairy cow's natural life expectancy is about twenty years. In battery cage and free-range egg production, unwanted male chicks are culled or discarded at birth during the process of securing a further generation of egg-laying hens.
Ethical vegetarianism has become popular in developed countries particularly because of the spread of factory farming , faster communications, and environmental consciousness.
Some believe that the current mass demand for meat cannot be satisfied without a mass-production system that disregards the welfare of animals, while others believe that practices like well-managed free-ranging and consumption of game, particularly from species whose natural predators have been significantly eliminated, could substantially alleviate the demand for mass-produced meat.
Ancient Greek philosophy has a long tradition of vegetarianism. Pythagoras was reportedly vegetarian and studied at Mt. Carmel, where some historians say there was a vegetarian community , as his followers were expected to be. Roman writer Ovid concluded his magnum opus Metamorphoses , in part, with the impassioned argument uttered by the character of Pythagoras that in order for humanity to change, or metamorphose , into a better, more harmonious species, it must strive towards more humane tendencies.
He cited vegetarianism as the crucial decision in this metamorphosis, explaining his belief that human life and animal life are so entwined that to kill an animal is virtually the same as killing a fellow human. Everything changes; nothing dies; the soul roams to and fro, now here, now there, and takes what frame it will, passing from beast to man, from our own form to beast and never dies Therefore lest appetite and greed destroy the bonds of love and duty, heed my message!
Never by slaughter dispossess souls that are kin and nourish blood with blood! Jainism teaches vegetarianism as moral conduct as do some major  sects of Hinduism. Buddhism in general does not prohibit meat eating, while Mahayana Buddhism encourages vegetarianism as beneficial for developing compassion.
Sikhism    does not equate spirituality with diet and does not specify a vegetarian or meat diet. Theravadins in general eat meat. In the Theravada canon, Buddha did not make any comment discouraging them from eating meat except specific types, such as human, elephant meat , horse, dog, snake, lion, tiger, leopard, bear, and hyena flesh  but he specifically refused to institute vegetarianism in his monastic code when a suggestion had been made.
In several Sanskrit texts of Mahayana Buddhism , Buddha instructs his followers to avoid meat. Christians have always been free to make their own decisions about what to eat; however, there are groups within Christianity that practice specific dietary restrictions for various reasons. Surviving fragments from their Gospel indicate their belief that — as Christ is the Passover sacrifice and eating the Passover lamb is no longer required — a vegetarian diet may or should be observed.
However, orthodox Christianity does not accept their teaching as authentic.