No-carbohydrate diet
Encyclopedia
A no-carbohydrate diet is described as human carnivorism. It excludes dietary consumption of all carbohydrates and suggests fat as the main source of energy with sufficient protein. A no-carbohydrate diet is ketogenic, which means it causes the body to go into a state of ketosis
(converting dietary fat and body fat into ketone bodies
and using them to fuel the entire body and up to 95% of the brain. The remaining 5% still runs on glucose which is adequately supplied by converting dietary protein via gluconeogenesis
or by converting glycerol
from the breakdown of fat). It uses mainly animal source foods
and requires a high saturated fat intake.
, a Canadian explorer who lived with the Inuit
for some time, and who witnessed their diet as essentially consisting of meat and fish, with very few carbohydrates - berries during the summer. Stefansson and a friend later volunteered for a one year experiment at Bellevue Hospital in New York to prove he could thrive on a diet of nothing but meat, meat fat and internal organs of animals. His progress was closely monitored and experiments were done on his health throughout the year. At the end of the year, he did not show any symptoms of ill health; he did not develop scurvy
, which many scientists had expected to manifest itself only a few months into the diet due to the lack of vitamin C
in muscle meat. However, Stefansson and his partner did not eat just muscle meat - they ate fat, raw brain, raw liver (a significant source of vitamin C and others), and other varieties of offal
.
One of the first registries on No-carbohydrate diets was in 1860 when English casket maker William Banting was prompted to lose weight and decided to write “Letter on Corpulence”, which aimed to completely avoid starch and sugar. Mr Banting lost 45 pounds, basing on a diet composed by lean meat, dry toast, soft boiled eggs and a few drinks a day. Thus, the Banting diet became a very well known method back then in the 19th century, promoted also for weight loss and diabetes control.
More than a century after this, carbohydrate-restricted diets gained great popularity, particularly in the case of the Atkins Diet which emerged in 1972, thanks to Dr Robert Atkins. While his diet is not a zero-carbohydrate diet, it does reduce carb intake to a ketogenic level in its initial stages (20 grams daily in induction; weekly increase of 5 thereafter), allowing followers to take advantage of the fat burning mechanism that is ketosis. According to him, this nutritional approach turns out to be more effective for weight loss than a low-fat, “high carbohydrate diet”, although there has always been much controversy and great dispute amongst healthcare professionals concerning drastic carbohydrate restriction.
Meat: Followers of this diet can consume almost any kind of white and red meat.
Seafood: All types of fish can be consumed: tuna, sole, trout, flounder, sardines and herring.
Eggs: The best way to consume them is to boil them.
Cheese: Cheddar, goat cheese, Gouda, Mozzarella, and Bleu cheese.
Fat: Consumption is limited to natural and not hydrogenated animal fats, such as real unsalted butter, heavy cream, suet, lard and marrow.
According to observational and prospectively designed studies from physicians and nutrition scientists, impaired physical performance is a common but not an obligate result of a low carbohydrate diet or no-carbohydrate diet. However, therapeutic use of ketogenic diets should not require restriction of any physical labor or recreational activity, with the particularity that only anaerobic performance is limited, such as weight lifting. In this case, due to the low glycogen levels in the ketogenic diet, competitive athletes cannot follow this kind of diet.
In 1939 two Danish scientists, Christensen and Hansen, made a study of low carbohydrate, moderate carbohydrate and high carbohydrate diets, each one lasting at least one week. At the end of each diet, the subjects' endurance time to exhaustion on a stationery bicycle was measured, and they found that with the low carbohydrate they lasted only 81 minutes, while they were able to ride for 206 minutes after the high carbohydrates diet.
In 1946, another experiment was made by Kark, Johnson and Lewis to determine effects of pemmican (a mixture of fat and dry meat) as an emergency ration for infantry troops in winter training in the Canadian Arctic. Results on this study showed that in 3 days, soldiers were unable to complete their assigned tasks. Then, in the 1960s, with the resurgence of biomedical science, new research revealed that fat had limited utility as fuel for high intensity exercise, and that humans are physically impaired if they are given a low carbohydrate or no-carbohydrate diet.
At the Center for Obesity Research and Education at Temple University, Philadelphia, researchers found recently that after a 2 year comparison, a low carbohydrate diet is almost similar to low-fat diet in terms of weight loss, but low-carbohydrate improves cardiovascular risk factors more, such as blood pressure and lipid levels. This study would suggest that low-carbohydrate diet protects individuals from potential coronary heart diseases in a more effective way. 307 patients were randomly assigned to either one of the two diets and researchers found 2 years later that good cholesterol levels were higher among the low-carbohydrate group compared to the low-fat group, 23% and 11% respectively.
On the other side, a study by the Beth Israel Deaconess Medical Center (BIDMC), a teaching hospital of Harvard Medical School, revealed after a study made on mice with different diets that with a low-carbohydrate there is a significant impact on atherosclerosis, even though it didn't affect cholesterol levels. Anthony Rosenzweig, a professor of Medicine at Harvard Medical School, found that the increase in plaque build-up in the blood vessels and the impaired ability to form new vessels were associated with a reduction in vascular progenitor cells, which some researchers claim could play a protective role in keeping vascular health.
, who traditionally obtain most of their dietary energy from wild animals
and therefore eat a low-carbohydrate diet, seem to have a high mortality
from coronary heart disease
, but the study did not control for carbohydrate consumption or smoking, which is significant, considering it was a "westernized" Inuit population of which 79% were current smokers and more than likely ate a non-traditional diet.
There are still serious doubts about the long term effects on health adopting a no-carbohydrate diet. In 2005, the British Heart Foundation recommended not to follow these kind of diets, for those individuals who want to lose weight and take care of their heart. Working together with the Oxford University team, they found that the energy stored in the heart was reduced by an average of 16% among those who followed a high-fat, low-carbohydrate diet.
When the Beth Israel Deaconess Medical Center (BIDMC) found in their investigation that this diet is associated with serious artery damage in animals, the Stroke Association in the UK added that with foods as red meat and dairy products, containing high levels of saturated fat, are the ones that cause the buildup in the arteries. Researchers suggested having a moderate and balanced diet, coupled with regular exercise.
Ketosis
Ketosis is a state of elevated levels of ketone bodies in the body. It is almost always generalized throughout the body, with hyperketonemia, that is, an elevated level of ketone bodies in the blood. Ketone bodies are formed by ketogenesis when the liver glycogen stores are depleted...
(converting dietary fat and body fat into ketone bodies
Ketone bodies
Ketone bodies are three water-soluble compounds that are produced as by-products when fatty acids are broken down for energy in the liver and kidney. They are used as a source of energy in the heart and brain. In the brain, they are a vital source of energy during fasting...
and using them to fuel the entire body and up to 95% of the brain. The remaining 5% still runs on glucose which is adequately supplied by converting dietary protein via gluconeogenesis
Gluconeogenesis
Gluconeogenesis is a metabolic pathway that results in the generation of glucose from non-carbohydrate carbon substrates such as lactate, glycerol, and glucogenic amino acids....
or by converting glycerol
Glycerol
Glycerol is a simple polyol compound. It is a colorless, odorless, viscous liquid that is widely used in pharmaceutical formulations. Glycerol has three hydroxyl groups that are responsible for its solubility in water and its hygroscopic nature. The glycerol backbone is central to all lipids...
from the breakdown of fat). It uses mainly animal source foods
Animal source foods
Animal source foods include any food item that comes from an animal source such as meat, milk, fish, eggs, cheese and yogurt. Many individuals do not consume ASF or consume little ASF by either personal choice or necessity as ASF may not be accessible or available to these people.- Nutrition of...
and requires a high saturated fat intake.
History
The earliest and primary proponent of an all animal-based diet was Vilhjalmur StefanssonVilhjalmur Stefansson
Vilhjalmur Stefansson was a Canadian Arctic explorer and ethnologist.-Early life:Stefansson, born William Stephenson, was born at Gimli, Manitoba, Canada, in 1879. His parents had emigrated from Iceland to Manitoba two years earlier...
, a Canadian explorer who lived with the Inuit
Inuit
The Inuit are a group of culturally similar indigenous peoples inhabiting the Arctic regions of Canada , Denmark , Russia and the United States . Inuit means “the people” in the Inuktitut language...
for some time, and who witnessed their diet as essentially consisting of meat and fish, with very few carbohydrates - berries during the summer. Stefansson and a friend later volunteered for a one year experiment at Bellevue Hospital in New York to prove he could thrive on a diet of nothing but meat, meat fat and internal organs of animals. His progress was closely monitored and experiments were done on his health throughout the year. At the end of the year, he did not show any symptoms of ill health; he did not develop scurvy
Scurvy
Scurvy is a disease resulting from a deficiency of vitamin C, which is required for the synthesis of collagen in humans. The chemical name for vitamin C, ascorbic acid, is derived from the Latin name of scurvy, scorbutus, which also provides the adjective scorbutic...
, which many scientists had expected to manifest itself only a few months into the diet due to the lack of vitamin C
Vitamin C
Vitamin C or L-ascorbic acid or L-ascorbate is an essential nutrient for humans and certain other animal species. In living organisms ascorbate acts as an antioxidant by protecting the body against oxidative stress...
in muscle meat. However, Stefansson and his partner did not eat just muscle meat - they ate fat, raw brain, raw liver (a significant source of vitamin C and others), and other varieties of offal
Offal
Offal , also called, especially in the United States, variety meats or organ meats, refers to the internal organs and entrails of a butchered animal. The word does not refer to a particular list of edible organs, which varies by culture and region, but includes most internal organs other than...
.
One of the first registries on No-carbohydrate diets was in 1860 when English casket maker William Banting was prompted to lose weight and decided to write “Letter on Corpulence”, which aimed to completely avoid starch and sugar. Mr Banting lost 45 pounds, basing on a diet composed by lean meat, dry toast, soft boiled eggs and a few drinks a day. Thus, the Banting diet became a very well known method back then in the 19th century, promoted also for weight loss and diabetes control.
More than a century after this, carbohydrate-restricted diets gained great popularity, particularly in the case of the Atkins Diet which emerged in 1972, thanks to Dr Robert Atkins. While his diet is not a zero-carbohydrate diet, it does reduce carb intake to a ketogenic level in its initial stages (20 grams daily in induction; weekly increase of 5 thereafter), allowing followers to take advantage of the fat burning mechanism that is ketosis. According to him, this nutritional approach turns out to be more effective for weight loss than a low-fat, “high carbohydrate diet”, although there has always been much controversy and great dispute amongst healthcare professionals concerning drastic carbohydrate restriction.
No-Carbohydrate Foods
No-Carbohydrate diet is an extreme form of low-carbohydrate diets. The following is a list of foods that can be eaten due to their lack of carbohydrates:Meat: Followers of this diet can consume almost any kind of white and red meat.
Seafood: All types of fish can be consumed: tuna, sole, trout, flounder, sardines and herring.
Eggs: The best way to consume them is to boil them.
Cheese: Cheddar, goat cheese, Gouda, Mozzarella, and Bleu cheese.
Fat: Consumption is limited to natural and not hydrogenated animal fats, such as real unsalted butter, heavy cream, suet, lard and marrow.
Medical research
- In lab tests on mice, prostate tumors grow slower with a no-carbohydrate diet. A study led by Duke University Prostate Center researchers in 2007 prove also in mice that low-carbohydrate diet may slow tumor growth of prostate tumors. This due to a reduction on insulin and insulin-like growth factor (IGF), substances that are linked with the growth of prostate tumors in previous research. Mice were fed with 3 different diets and researchers found that mice that ate a low-carbohydrate diet had the longest survival and smaller tumor size.
- "A high fat, high protein and no carbohydrate diet and similar drink, ClearScan, decreased myocardial uptake in oncology studies" when compared to fasting.
Side effects of this diet:
According to observational and prospectively designed studies from physicians and nutrition scientists, impaired physical performance is a common but not an obligate result of a low carbohydrate diet or no-carbohydrate diet. However, therapeutic use of ketogenic diets should not require restriction of any physical labor or recreational activity, with the particularity that only anaerobic performance is limited, such as weight lifting. In this case, due to the low glycogen levels in the ketogenic diet, competitive athletes cannot follow this kind of diet.
In 1939 two Danish scientists, Christensen and Hansen, made a study of low carbohydrate, moderate carbohydrate and high carbohydrate diets, each one lasting at least one week. At the end of each diet, the subjects' endurance time to exhaustion on a stationery bicycle was measured, and they found that with the low carbohydrate they lasted only 81 minutes, while they were able to ride for 206 minutes after the high carbohydrates diet.
In 1946, another experiment was made by Kark, Johnson and Lewis to determine effects of pemmican (a mixture of fat and dry meat) as an emergency ration for infantry troops in winter training in the Canadian Arctic. Results on this study showed that in 3 days, soldiers were unable to complete their assigned tasks. Then, in the 1960s, with the resurgence of biomedical science, new research revealed that fat had limited utility as fuel for high intensity exercise, and that humans are physically impaired if they are given a low carbohydrate or no-carbohydrate diet.
At the Center for Obesity Research and Education at Temple University, Philadelphia, researchers found recently that after a 2 year comparison, a low carbohydrate diet is almost similar to low-fat diet in terms of weight loss, but low-carbohydrate improves cardiovascular risk factors more, such as blood pressure and lipid levels. This study would suggest that low-carbohydrate diet protects individuals from potential coronary heart diseases in a more effective way. 307 patients were randomly assigned to either one of the two diets and researchers found 2 years later that good cholesterol levels were higher among the low-carbohydrate group compared to the low-fat group, 23% and 11% respectively.
On the other side, a study by the Beth Israel Deaconess Medical Center (BIDMC), a teaching hospital of Harvard Medical School, revealed after a study made on mice with different diets that with a low-carbohydrate there is a significant impact on atherosclerosis, even though it didn't affect cholesterol levels. Anthony Rosenzweig, a professor of Medicine at Harvard Medical School, found that the increase in plaque build-up in the blood vessels and the impaired ability to form new vessels were associated with a reduction in vascular progenitor cells, which some researchers claim could play a protective role in keeping vascular health.
Criticism
Alexander Ströhle, Maike Wolters and Andreas Hahn, with the Department of Food Science at the University of Hannover, rely on Bjerregaard et al. (2003) to argue that hunters like the InuitInuit
The Inuit are a group of culturally similar indigenous peoples inhabiting the Arctic regions of Canada , Denmark , Russia and the United States . Inuit means “the people” in the Inuktitut language...
, who traditionally obtain most of their dietary energy from wild animals
Game (food)
Game is any animal hunted for food or not normally domesticated. Game animals are also hunted for sport.The type and range of animals hunted for food varies in different parts of the world. This will be influenced by climate, animal diversity, local taste and locally accepted view about what can or...
and therefore eat a low-carbohydrate diet, seem to have a high mortality
Mortality rate
Mortality rate is a measure of the number of deaths in a population, scaled to the size of that population, per unit time...
from 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...
, but the study did not control for carbohydrate consumption or smoking, which is significant, considering it was a "westernized" Inuit population of which 79% were current smokers and more than likely ate a non-traditional diet.
There are still serious doubts about the long term effects on health adopting a no-carbohydrate diet. In 2005, the British Heart Foundation recommended not to follow these kind of diets, for those individuals who want to lose weight and take care of their heart. Working together with the Oxford University team, they found that the energy stored in the heart was reduced by an average of 16% among those who followed a high-fat, low-carbohydrate diet.
When the Beth Israel Deaconess Medical Center (BIDMC) found in their investigation that this diet is associated with serious artery damage in animals, the Stroke Association in the UK added that with foods as red meat and dairy products, containing high levels of saturated fat, are the ones that cause the buildup in the arteries. Researchers suggested having a moderate and balanced diet, coupled with regular exercise.
See also
- Carbohydrate metabolismCarbohydrate metabolismCarbohydrate metabolism denotes the various biochemical processes responsible for the formation, breakdown and interconversion of carbohydrates in living organisms....
- CarnivoreCarnivoreA carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of animal tissue, whether through predation or scavenging...
- Country foodCountry foodCountry food, in Canada, refers to the traditional diets of Aboriginal people , especially in remote northern regions where Western food is an expensive import, and traditional foods are still relied upon.- First Nations :...
/ Inuit dietInuit dietInuit consume a diet of foods that are fished, hunted, and gathered locally. This may include walrus, Ringed Seal, Bearded Seal, beluga whale, caribou, polar bear, muskoxen, birds and fish. While it is not possible to cultivate plants for food in the Arctic the Inuit have traditionally gathered...
, the traditional diet of the Inuit and First Nations - Ketogenic dietKetogenic dietThe ketogenic diet is a high-fat, adequate-protein, low-carbohydrate diet that in medicine is used primarily to treat difficult-to-control epilepsy in children. The diet mimics aspects of starvation by forcing the body to burn fats rather than carbohydrates...
- Low-carbohydrate dietLow-carbohydrate dietLow-carbohydrate diets or low-carb diets are dietary programs that restrict carbohydrate consumption usually for weight control or for the treatment of obesity. Foods high in digestible carbohydrates are limited or replaced with foods containing a higher percentage of proteins and fats...
- Vilhjalmur StefanssonVilhjalmur StefanssonVilhjalmur Stefansson was a Canadian Arctic explorer and ethnologist.-Early life:Stefansson, born William Stephenson, was born at Gimli, Manitoba, Canada, in 1879. His parents had emigrated from Iceland to Manitoba two years earlier...
Further reading
- Not Eating Enough: Overcoming Underconsumption of Military Operational Rations (1995) "Chapter 16: The Functional Effects of Carbohydrate and Energy Underconsumption" Institute of Medicine (IOM)