Atkins Nutritional Approach
Encyclopedia
The Atkins diet, officially called the Atkins Nutritional Approach, is a low-carbohydrate diet
created by Robert Atkins
from a research paper he read in the Journal of the American Medical Association
published by Gordon Azar and Walter Lyons Bloom. Atkins stated that he used the study to resolve his own overweight
condition. He later popularized the method in a series of books, starting with Dr. Atkins' Diet Revolution in 1972. In his second book, Dr. Atkins' New Diet Revolution (2002), he modified parts of the diet but did not alter the original concepts.
from metabolizing glucose
as energy over to converting stored body fat to energy. This process, called ketosis
, begins when insulin levels are low; in normal humans, insulin
is lowest when blood glucose levels are low (mostly before eating). Ketosis lipolysis
occurs when some of the lipid stored in fat cells are transferred to the blood and are thereby used for energy. On the other hand, caloric carbohydrates (for example, glucose or starch
, the latter made of chains of glucose) impact the body by increasing blood sugar
after consumption. (In the treatment of diabetes, blood sugar levels are used to determine a patient's daily insulin requirements.) Fiber, because of its low digestibility, provides little or no food energy
and does not significantly impact glucose and insulin levels.
In his book Dr Atkins' New Diet Revolution, Atkins made the controversial argument that the low-carbohydrate diet produces a metabolic advantage
because "burning fat takes more calories so you expend more calories." He cited one study where he estimated this advantage to be 950 calories (4.0 MJ) per day. A review study published in the Lancet concluded that there was no such metabolic advantage and dieters were simply eating fewer calories because of boredom. Professor Astrup stated, "The monotony and simplicity of the diet could inhibit appetite and food intake".
The Atkins Diet restricts "net carbs" (digestible carbohydrates that impact blood sugar). One effect is a tendency to decrease the onset of hunger, perhaps because of longer duration of digestion (fats and proteins take longer to digest than carbohydrates). Atkins states in his 2002 book New Diet Revolution that hunger is the number one reason why low-fat diets fail and that the Atkins diet is easier because you are allowed to eat as much as you want.
Net carbohydrates can be calculated from a food source by subtracting fiber and sugar alcohol
s (which are shown to have a smaller effect on blood sugar levels) from total carbohydrates. Sugar alcohols contain about two calories per gram, and the American Diabetes Association
recommends that diabetics count each gram as half a gram of carbohydrate. Fructose
(for example, as found in many industrial sweeteners) has four calories per gram but has a very low glycemic index and does not cause insulin production, probably because ß cells have low levels of GLUT5. Leptin, an appetite regulating hormone, is however not triggered following consumption of fructose. This creates an unsatisfying feeling after consumption, promoting binge behavior that culminates in an increased blood triglyceride level arising from fructose conversion by the liver.
Preferred foods in all categories are whole, unprocessed foods with a low glycemic index
, although restrictions for low glycemic carbohydrates (black rice, vegetables, etc.) are the same as those for high glycemic carbohydrates (sugar, white bread). Atkins Nutritionals, the company formed to market foods which work with the Atkins Diet, recommends that no more than 20% of calories eaten while on the diet come from saturated fat
.
Atkins' book, Atkins Diabetes Revolution, states that, for people whose blood sugar is abnormally high or who have Type 2 diabetes mellitus
, the Atkins diet decreases or eliminates the need for drugs to treat these conditions. The Atkins Blood Sugar Control Program (ABSCP) is an individualized approach to weight control and permanent management of the risk factors for diabetes and cardiovascular disease. Nevertheless, the causes of Type 2 diabetes remain obscure, and the Atkins Diet is not accepted in conventional therapy for diabetes.
. In ketogenic diets there is production of ketones that contribute to the energy production in the Krebs cycle.
Ketogenic diets rely on the insulin response to blood glucose. Because ketogenic dieters eat few carbohydrates, there is no glucose that can trigger the insulin response. When there is no glucose-insulin response there are some hormonal changes that cause the stored fat to be used for energy. Blood glucose levels have to decrease to less than 3.58 mmol/L for growth hormone
, epinephrine
, and glucagon
to be released to maintain energy metabolism. In the adipose cells, growth hormone and epinephrine initiate the triacylglycerol to be broken down to fatty acids. These fatty acids go to the liver and muscle where they should be oxidized and give acetyl-CoA that enters the Krebs cycle directly. However, the excess acetyl-CoA in the liver is converted to ketones (ketone bodies), that are transported to other tissues. In these tissues they are converted back into acetyl-CoA in order to enter the Krebs cycle. Glucagon is produced when blood glucose is too low, and it causes the liver to start breaking glycogen
into glucose
. Since the dieter does not eat any more carbohydrates, there is no glycogen in the liver to be broken down, so the liver converts fats into free fatty acids and ketone bodies, and this process is called ketosis. Because of this, the body is forced to use fats as a primary fuel source.
increased, and insulin resistance
improved much more in dieters following the Atkins diet than in those following a low-fat, calorie restricted diet. Harper also mentions that there had not been enough prior research to allow him to confidently say that Atkins is safe to be recommended to patients.
(MG) before and after starting the Atkins diet. MG is associated with blood vessel and tissue damage, and is higher in people with poorly controlled diabetes. The study found that MG levels doubled shortly after the diet was started, noting that the MG rise was related to the presence of ketosis. A rise in acetol and acetone was found, indicating that MG was produced by oxidation. MG also arose as a by-product of triglyceride breakdown and from lipoxidation (ketosis related to fat intake).
Whether or not increased methylglyoxal is harmful to human beings has been questioned by the Indian Association for the Cultivation of Science, who in a 2008 critical overview of various studies (including Beisswenger's study) state, "The authors present a brief critical overview of studies indicating both toxic and beneficial effects of methylglyoxal and suggest that the beneficial effects of methylglyoxal outweigh its toxic effects." While not drawing any definite conclusions, the Indian Association for the Cultivation of Science recommends further study especially in the area of using methylglyoxal to cure or treat cancer.
. Carbohydrate intake is limited to less than 20 net gram
s per day (grams of carbohydrates minus grams of fiber, sugar alcohol
s, or glycerin), 12 to 15 net grams of which must come in the form of salad greens and other fruits and vegetables such as broccoli
, spinach, pumpkin, cauliflower
, turnips, tomatoes, and asparagus
, to name a few of the 54 allowed by Atkins (but not legumes, since they are too starchy for the induction phase). The allowed foods include a liberal amount of all meats, poultry
, fish, shellfish, fowl
, and eggs; up to 4 ounces (113 g) of soft or semi-soft cheese
such as cheddar cheese; most salad vegetables; other low carbohydrate vegetables; and butter, olive oil and vegetable oils. Drinking eight glasses of water per day is a requirement during this phase. Alcoholic beverages are not allowed during this phase. Caffeine
is allowed in moderation so long as it does not cause cravings or low blood sugar. If a caffeine addiction is evident, it is best to not allow it until later phases of the diet. A daily multivitamin with minerals, except iron, is also recommended.
A normal amount of food, on Induction, is around 20 grams of sugar (or net carb), at least 100 grams of fat.
The Induction phase is usually when many see the most significant weight loss — reports of losses of 5 to 10 pounds per week are not uncommon when Induction is combined with daily exercise.
Many Atkins followers make use of Ketostix, small chemically reactive strips used by diabetics
. These let the dieter monitor when they enter the ketosis, or fat burning phase, but are not always accurate for non-diabetic users. Other indicators of ketosis
include a metallic taste in the mouth, or a sweet smell on breath (the smell of Ketones).
During the first week, one should add more of the induction acceptable vegetables to one's daily products. For example, 6-8 stalks of asparagus, salad, one cup of cauliflower or one half of avocado. The next week, one should follow the carbohydrate ladder that Dr Atkins created for this phase and add fresh dairy. The ladder has 9 rungs and should be added in order given. One can skip a rung if one does not intend to include that food group in one's permanent way of eating, such as the alcohol rung.
The rungs are as follows:
on a testing stick. As a result, it is not necessary to maintain a positive ketosis test long term.
n adults was on the diet. This large following was blamed for large declines in the sales of carbohydrate-heavy foods like pasta
and rice
: sales were down 8.2 and 4.6 percent, respectively, in 2003. The diet's success was even blamed for a decline in Krispy Kreme
sales. Trying to capitalize on the "low-carb craze," many companies released special product lines that were low in carbohydrates. Coca-Cola
released C2
and Pepsi-Cola created Pepsi Edge, which was scheduled to be discontinued later in 2005. Unlike the sugar-free soft drinks Diet Coke
and Diet Pepsi
, which had been available for decades, these new drinks used a blend of sugar and artificial sweeteners to offset the flavor of artificial sweetener. These "half-and-half" drinks declined in popularity as soft drink makers learned to use newer sweeteners to mask the flavour of aspartame
(or completely replace it) in reformulated diet drinks such as Coca-Cola Zero
and Pepsi ONE
.
Low-carbohydrate diets and the societal changes they have caused have been a subject of interest in the news and popular media. For example, on 25 April 2004, Canada
's Food Network
aired a one-hour television documentary entitled The Low Carb Revolution.
In 2003, Atkins died from a fatal head injury sustained in a fall on ice. His death came after being affected with some form of cardiomyopathy
(reportedly caused by a viral infection), which had been associated with noticeable weight fluctuation in his final years. This combination of circumstances led to rumors and allegations that Atkins had died from complications arising from his namesake nutritional plan; however, contemporary accounts from his physicians did not substantiate these claims.
On July 31, 2005, the Atkins Nutritional company filed for Chapter 11 bankruptcy protection after the percentage of adults on the diet declined to two percent and sales of Atkins brand product fell steeply in the second half of 2004. The company continues to operate and the diet plan remains popular, although it has not regained its former popularity.
A Swedish prospective study with a follow-up of approximately 10 years came to the conclusion that elderly Swedish men on a carbohydrate-restricted diet (however 40% carbohydrates compared to the Atkins recommended 4%) had a hazard ratio
of 1.2 for all-cause mortality compared to controls, and a hazard ratio of 1.4 for cardiovascular mortality.
In addition to research on the efficacy of Atkins and other low-carbohydrate diets, some research has directly addressed other areas of health affected by low-carbohydrate diets. For example, contrary to popular belief that low-carbohydrate diets damage the heart, one study found that women eating low-carbohydrate, high-fat/protein diets had the same or slightly less risk of coronary heart disease
, compared to women eating high-carbohydrate, low-fat diets. Other studies have found possible benefits to individuals with diabetes, cancer, and epilepsy. Nevertheless some studies demonstrate potentially harmful effects of certain types of low-carbohydrate diets including various metabolic and emotional side-effects.
found that the sample menu from the Atkins Nutritional Approach is one of the top five in the expense category of ten plans Forbes analyzed. This was due to the inclusion of recipes with some high cost ingredients such as lobster tails which were put in the book to demonstrate the variety of foods which could be consumed on the diet. The analysis showed the median average of the ten diets was approximately 50% higher, and Atkins 80% higher, than the American national average. The Atkins diet was less expensive than the Jenny Craig
diet and more expensive than Weight Watchers
.
Low-carbohydrate diets have been the subject of heated debate in medical circles for three decades. They are still controversial and only recently has any serious research supported some aspects of Atkins' claims, especially for short-term weight-loss (6 months or less).
In a comparison study by Dansinger and colleagues (2005), the goal was to compare popular diets like Atkins, Ornish, Weight Watchers, and Zone for the amount of weight lost and a heart disease risk reduction. In the study there were 247 individuals and it lasted for 1 year. All the subjects were overweight at baseline, and had an increased risk for cardiac diseases. One of the diets was assigned to each person.
The Atkins diet group ate 20g of CHO (carbohydrate) a day, with a gradual increase toward 50 g daily. The Zone group ate a 40-30-30 % diet of carbohydrates, fats and proteins respectively. The Weight Watchers group was to keep the “points” of their food in a determined range, based on their weight. The Ornish group ate a vegetarian diet with 10% of calories coming from fats.
The weight, waist size, blood pressure, and a blood sample were taken, at the beginning, after 2 months, 6 months and 12 months. All four diets resulted in weight loss with no significant difference between the diets.
But many in the scientific community also raise serious concerns:
Opponents of the diet also state that the initial weight loss
upon starting the diet is a phenomenon common with most diets, and is due to reduction in stored glycogen
and related water in muscles, not fat loss. They say that no evidence has surfaced that any diet will cause weight loss unless it reduces food energy
(calories) below the maintenance level and that weight loss from the Atkins diet may be the result of less food energy being consumed by the dieter, rather than the lack of carbohydrates. They further point out that weight loss on fad diets
, which typically restrict or prohibit certain foods, is often because the dieter has fewer food choices available.
Another common misconception arises from confusion between the Induction Phase and rest of the diet. The first two weeks of the Atkins Diet are strict, with only 20g of 'net' carbohydrates permitted per day. Net Carbs are the total carbohydrate content minus the fiber content. The Net Carbs number reflects the grams of carbohydrate that are said to significantly impact blood sugar level and therefore are the only carbs needed to count when doing Atkins. Most of the 20 or less grams of carbohydrates are to come from vegetables.
Atkins states that a dieter can safely stay at the Induction Phase for several months if the person has a lot of weight to lose. Induction, however, is merely a stage to get the body used to fat, and cure cravings for unacceptable foods. Gradually, carbohydrate levels are raised to slow weight loss and add more acceptable foods (berries, more dairy, nuts, etc.), though carbs are still significantly below USDA norms. Once the weight-loss goal is reached, carbohydrate levels are raised again to a state of equilibrium where no weight is lost or gained, which may or may not be below USDA norms, depending on the individual's metabolism, age, and their exercise level.
The company emerged from bankruptcy on January 10, 2006, introducing "a new business strategy that focuses on providing great-tasting portable foods with a unique nutrition advantage to healthy, active men and women." Although the marketing focus has changed, the products are still low-carb. It is also stated on the packages the stage of the Atkins Nutritional Approach where they may be used.
Low-carbohydrate diet
Low-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...
created by Robert Atkins
Robert Atkins (nutritionist)
Robert Coleman Atkins, MD was an American physician and cardiologist, best known for the Atkins Nutritional Approach , a popular but controversial way of dieting that entails close control of carbohydrate consumption, emphasizing protein and fat intake, including saturated fat in addition to...
from a research paper he read in 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 ...
published by Gordon Azar and Walter Lyons Bloom. Atkins stated that he used the study to resolve his own overweight
Overweight
Overweight is generally defined as having more body fat than is optimally healthy. Being overweight is a common condition, especially where food supplies are plentiful and lifestyles are sedentary...
condition. He later popularized the method in a series of books, starting with Dr. Atkins' Diet Revolution in 1972. In his second book, Dr. Atkins' New Diet Revolution (2002), he modified parts of the diet but did not alter the original concepts.
Nature of the diet
The Atkins diet involves limited consumption of carbohydrates to switch the body's metabolismMetabolism
Metabolism is the set of chemical reactions that happen in the cells of living organisms to sustain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories...
from metabolizing glucose
Glucose
Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...
as energy over to converting stored body fat to energy. This process, called ketosis
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...
, begins when insulin levels are low; in normal humans, insulin
Insulin
Insulin is a hormone central to regulating carbohydrate and fat metabolism in the body. Insulin causes cells in the liver, muscle, and fat tissue to take up glucose from the blood, storing it as glycogen in the liver and muscle....
is lowest when blood glucose levels are low (mostly before eating). Ketosis lipolysis
Lipolysis
Lipolysis is the breakdown of lipids and involves the hydrolysis of triglycerides into free fatty acids followed by further degradation into acetyl units by beta oxidation. The process produces Ketones, which are found in large quantities in ketosis, a metabolic state that occurs when the liver...
occurs when some of the lipid stored in fat cells are transferred to the blood and are thereby used for energy. On the other hand, caloric carbohydrates (for example, glucose or starch
Starch
Starch or amylum is a carbohydrate consisting of a large number of glucose units joined together by glycosidic bonds. This polysaccharide is produced by all green plants as an energy store...
, the latter made of chains of glucose) impact the body by increasing blood sugar
Blood sugar
The blood sugar concentration or blood glucose level is the amount of glucose present in the blood of a human or animal. Normally in mammals, the body maintains the blood glucose level at a reference range between about 3.6 and 5.8 mM , or 64.8 and 104.4 mg/dL...
after consumption. (In the treatment of diabetes, blood sugar levels are used to determine a patient's daily insulin requirements.) Fiber, because of its low digestibility, provides little or no food energy
Food energy
Food energy is the amount of energy obtained from food that is available through cellular respiration.Food energy is expressed in food calories or kilojoules...
and does not significantly impact glucose and insulin levels.
In his book Dr Atkins' New Diet Revolution, Atkins made the controversial argument that the low-carbohydrate diet produces a metabolic advantage
Metabolic advantage
Metabolic Advantage is a term used in nutrition to describe the ability of a diet to achieve greater weight loss than another diet of equivalent calories...
because "burning fat takes more calories so you expend more calories." He cited one study where he estimated this advantage to be 950 calories (4.0 MJ) per day. A review study published in the Lancet concluded that there was no such metabolic advantage and dieters were simply eating fewer calories because of boredom. Professor Astrup stated, "The monotony and simplicity of the diet could inhibit appetite and food intake".
The Atkins Diet restricts "net carbs" (digestible carbohydrates that impact blood sugar). One effect is a tendency to decrease the onset of hunger, perhaps because of longer duration of digestion (fats and proteins take longer to digest than carbohydrates). Atkins states in his 2002 book New Diet Revolution that hunger is the number one reason why low-fat diets fail and that the Atkins diet is easier because you are allowed to eat as much as you want.
Net carbohydrates can be calculated from a food source by subtracting fiber and sugar alcohol
Sugar alcohol
A sugar alcohol is a hydrogenated form of carbohydrate, whose carbonyl group has been reduced to a primary or secondary hydroxyl group . Sugar alcohols have the general formula Hn+1H, whereas sugars have HnHCO...
s (which are shown to have a smaller effect on blood sugar levels) from total carbohydrates. Sugar alcohols contain about two calories per gram, and the American Diabetes Association
American Diabetes Association
The American Diabetes Association is a United States-based association working to fight the consequences of diabetes, and to help those affected by diabetes...
recommends that diabetics count each gram as half a gram of carbohydrate. Fructose
Fructose
Fructose, or fruit sugar, is a simple monosaccharide found in many plants. It is one of the three dietary monosaccharides, along with glucose and galactose, that are absorbed directly into the bloodstream during digestion. Fructose was discovered by French chemist Augustin-Pierre Dubrunfaut in 1847...
(for example, as found in many industrial sweeteners) has four calories per gram but has a very low glycemic index and does not cause insulin production, probably because ß cells have low levels of GLUT5. Leptin, an appetite regulating hormone, is however not triggered following consumption of fructose. This creates an unsatisfying feeling after consumption, promoting binge behavior that culminates in an increased blood triglyceride level arising from fructose conversion by the liver.
Preferred foods in all categories are whole, unprocessed foods with a low glycemic index
Glycemic index
The glycemic index, glycaemic index, or GI is a measure of the effects of carbohydrates on blood sugar levels. Carbohydrates that break down quickly during digestion and release glucose rapidly into the bloodstream have a high GI; carbohydrates that break down more slowly, releasing glucose more...
, although restrictions for low glycemic carbohydrates (black rice, vegetables, etc.) are the same as those for high glycemic carbohydrates (sugar, white bread). Atkins Nutritionals, the company formed to market foods which work with the Atkins Diet, recommends that no more than 20% of calories eaten while on the diet come from 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...
.
Atkins' book, Atkins Diabetes Revolution, states that, for people whose blood sugar is abnormally high or who have Type 2 diabetes mellitus
Diabetes mellitus
Diabetes mellitus, often simply referred to as diabetes, is a group of metabolic diseases in which a person has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced...
, the Atkins diet decreases or eliminates the need for drugs to treat these conditions. The Atkins Blood Sugar Control Program (ABSCP) is an individualized approach to weight control and permanent management of the risk factors for diabetes and cardiovascular disease. Nevertheless, the causes of Type 2 diabetes remain obscure, and the Atkins Diet is not accepted in conventional therapy for diabetes.
Ketogenic diet
The induction phase of the Atkins diet is a ketogenic dietKetogenic diet
The 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...
. In ketogenic diets there is production of ketones that contribute to the energy production in the Krebs cycle.
Ketogenic diets rely on the insulin response to blood glucose. Because ketogenic dieters eat few carbohydrates, there is no glucose that can trigger the insulin response. When there is no glucose-insulin response there are some hormonal changes that cause the stored fat to be used for energy. Blood glucose levels have to decrease to less than 3.58 mmol/L for growth hormone
Growth hormone
Growth hormone is a peptide hormone that stimulates growth, cell reproduction and regeneration in humans and other animals. Growth hormone is a 191-amino acid, single-chain polypeptide that is synthesized, stored, and secreted by the somatotroph cells within the lateral wings of the anterior...
, epinephrine
Epinephrine
Epinephrine is a hormone and a neurotransmitter. It increases heart rate, constricts blood vessels, dilates air passages and participates in the fight-or-flight response of the sympathetic nervous system. In chemical terms, adrenaline is one of a group of monoamines called the catecholamines...
, and glucagon
Glucagon
Glucagon, a hormone secreted by the pancreas, raises blood glucose levels. Its effect is opposite that of insulin, which lowers blood glucose levels. The pancreas releases glucagon when blood sugar levels fall too low. Glucagon causes the liver to convert stored glycogen into glucose, which is...
to be released to maintain energy metabolism. In the adipose cells, growth hormone and epinephrine initiate the triacylglycerol to be broken down to fatty acids. These fatty acids go to the liver and muscle where they should be oxidized and give acetyl-CoA that enters the Krebs cycle directly. However, the excess acetyl-CoA in the liver is converted to ketones (ketone bodies), that are transported to other tissues. In these tissues they are converted back into acetyl-CoA in order to enter the Krebs cycle. Glucagon is produced when blood glucose is too low, and it causes the liver to start breaking glycogen
Glycogen
Glycogen is a molecule that serves as the secondary long-term energy storage in animal and fungal cells, with the primary energy stores being held in adipose tissue...
into glucose
Glucose
Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...
. Since the dieter does not eat any more carbohydrates, there is no glycogen in the liver to be broken down, so the liver converts fats into free fatty acids and ketone bodies, and this process is called ketosis. Because of this, the body is forced to use fats as a primary fuel source.
Main effects
The effects of the Atkins diet remain a subject of much debate. Some studies conclude that the Atkins diet helps prevent cardiovascular disease, lowers the low density lipoprotein (LDL) cholesterol, and increases the amount of HDL, or so-called "good" cholesterol. Some studies suggest that the diet could contribute to osteoporosis and kidney stones. A University of Maryland study, in which test subjects were given calorie increases whenever their weight started to drop, showed higher LDL cholesterol and markers for inflammation.Cholesterol
According to Harper (2004) in a year-long study, the concentration of HDL cholesterolCholesterol
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...
increased, and insulin resistance
Insulin resistance
Insulin resistance is a physiological condition where the natural hormone insulin becomes less effective at lowering blood sugars. The resulting increase in blood glucose may raise levels outside the normal range and cause adverse health effects, depending on dietary conditions. Certain cell types...
improved much more in dieters following the Atkins diet than in those following a low-fat, calorie restricted diet. Harper also mentions that there had not been enough prior research to allow him to confidently say that Atkins is safe to be recommended to patients.
Methylglyoxal
A 2005 study by Beisswenger and colleagues compared levels of the glycotoxin methylglyoxalMethylglyoxal
Methylglyoxal, also called pyruvaldehyde or 2-oxopropanal is the aldehyde form of pyruvic acid. It has two carbonyl groups, so it is a dicarbonyl compound. Methylglyoxal is both an aldehyde and a ketone....
(MG) before and after starting the Atkins diet. MG is associated with blood vessel and tissue damage, and is higher in people with poorly controlled diabetes. The study found that MG levels doubled shortly after the diet was started, noting that the MG rise was related to the presence of ketosis. A rise in acetol and acetone was found, indicating that MG was produced by oxidation. MG also arose as a by-product of triglyceride breakdown and from lipoxidation (ketosis related to fat intake).
Whether or not increased methylglyoxal is harmful to human beings has been questioned by the Indian Association for the Cultivation of Science, who in a 2008 critical overview of various studies (including Beisswenger's study) state, "The authors present a brief critical overview of studies indicating both toxic and beneficial effects of methylglyoxal and suggest that the beneficial effects of methylglyoxal outweigh its toxic effects." While not drawing any definite conclusions, the Indian Association for the Cultivation of Science recommends further study especially in the area of using methylglyoxal to cure or treat cancer.
The four phases
There are four phases of the Atkins diet: induction, ongoing weight loss, pre-maintenance and lifetime maintenance.Induction
Induction is the most restrictive phase of the Atkins Nutritional Approach. Two weeks are recommended for this phase. It is intended to cause the body to quickly enter a state of ketosisKetosis
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...
. Carbohydrate intake is limited to less than 20 net gram
Gram
The gram is a metric system unit of mass....
s per day (grams of carbohydrates minus grams of fiber, sugar alcohol
Sugar alcohol
A sugar alcohol is a hydrogenated form of carbohydrate, whose carbonyl group has been reduced to a primary or secondary hydroxyl group . Sugar alcohols have the general formula Hn+1H, whereas sugars have HnHCO...
s, or glycerin), 12 to 15 net grams of which must come in the form of salad greens and other fruits and vegetables such as broccoli
Broccoli
Broccoli is a plant in the cabbage family, whose large flower head is used as a vegetable.-General:The word broccoli, from the Italian plural of , refers to "the flowering top of a cabbage"....
, spinach, pumpkin, cauliflower
Cauliflower
Cauliflower is one of several vegetables in the species Brassica oleracea, in the family Brassicaceae. It is an annual plant that reproduces by seed...
, turnips, tomatoes, and asparagus
Asparagus
Asparagus officinalis is a spring vegetable, a flowering perennialplant species in the genus Asparagus. It was once classified in the lily family, like its Allium cousins, onions and garlic, but the Liliaceae have been split and the onion-like plants are now in the family Amaryllidaceae and...
, to name a few of the 54 allowed by Atkins (but not legumes, since they are too starchy for the induction phase). The allowed foods include a liberal amount of all meats, poultry
Poultry
Poultry are domesticated birds kept by humans for the purpose of producing eggs, meat, and/or feathers. These most typically are members of the superorder Galloanserae , especially the order Galliformes and the family Anatidae , commonly known as "waterfowl"...
, fish, shellfish, fowl
Fowl
Fowl is a word for birds in general but usually refers to birds belonging to one of two biological orders, namely the gamefowl or landfowl and the waterfowl...
, and eggs; up to 4 ounces (113 g) of soft or semi-soft cheese
Cheese
Cheese is a generic term for a diverse group of milk-based food products. Cheese is produced throughout the world in wide-ranging flavors, textures, and forms....
such as cheddar cheese; most salad vegetables; other low carbohydrate vegetables; and butter, olive oil and vegetable oils. Drinking eight glasses of water per day is a requirement during this phase. Alcoholic beverages are not allowed during this phase. Caffeine
Caffeine
Caffeine is a bitter, white crystalline xanthine alkaloid that acts as a stimulant drug. Caffeine is found in varying quantities in the seeds, leaves, and fruit of some plants, where it acts as a natural pesticide that paralyzes and kills certain insects feeding on the plants...
is allowed in moderation so long as it does not cause cravings or low blood sugar. If a caffeine addiction is evident, it is best to not allow it until later phases of the diet. A daily multivitamin with minerals, except iron, is also recommended.
A normal amount of food, on Induction, is around 20 grams of sugar (or net carb), at least 100 grams of fat.
The Induction phase is usually when many see the most significant weight loss — reports of losses of 5 to 10 pounds per week are not uncommon when Induction is combined with daily exercise.
Many Atkins followers make use of Ketostix, small chemically reactive strips used by diabetics
Diabetes mellitus
Diabetes mellitus, often simply referred to as diabetes, is a group of metabolic diseases in which a person has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced...
. These let the dieter monitor when they enter the ketosis, or fat burning phase, but are not always accurate for non-diabetic users. Other indicators of ketosis
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...
include a metallic taste in the mouth, or a sweet smell on breath (the smell of Ketones).
Ongoing weight loss
The Ongoing Weight Loss (OWL) phase of Atkins consists of an increase in carbohydrate intake, but remaining at levels where weight loss occurs. The target daily carbohydrate intake increases each week by 5 net grams per day. A goal in OWL is to find the "Critical Carbohydrate Level for Losing" and to learn in a controlled manner how food groups in increasing glycemic levels and foods within that group affect your craving control. The OWL phase lasts until weight is within 10 pounds (4.5 kg) of the target weight.During the first week, one should add more of the induction acceptable vegetables to one's daily products. For example, 6-8 stalks of asparagus, salad, one cup of cauliflower or one half of avocado. The next week, one should follow the carbohydrate ladder that Dr Atkins created for this phase and add fresh dairy. The ladder has 9 rungs and should be added in order given. One can skip a rung if one does not intend to include that food group in one's permanent way of eating, such as the alcohol rung.
The rungs are as follows:
- Induction of acceptable vegetables in larger quantities
- Fresh cheese
- Nuts and seeds
- Berries
- Alcohol
- Legumes
- Other fruits
- Starchy vegetables
- Whole grains
Pre-maintenance
Daily net carbohydrates intake is increased again this time by 10 grams each week from the latter groupings, and the key goal in this phase is to find the "Critical Carbohydrate Level for Maintenance", this is the maximum number of carbohydrates you can eat each day without gaining weight. This may well be above the level of carbohydrates inducing ketosisKetosis
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...
on a testing stick. As a result, it is not necessary to maintain a positive ketosis test long term.
Lifetime maintenance
This phase is intended to carry on the habits acquired in the previous phases, and avoid the common end-of-diet mindset that can return people to their previous habits and previous weight. Whole, unprocessed food choices are emphasized, with the option to drop back to an earlier phase if you begin to gain weight.Popularity
The Atkins Nutritional Approach gained widespread popularity in 2003 and 2004. At the height of its popularity one in eleven North AmericaNorth America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
n adults was on the diet. This large following was blamed for large declines in the sales of carbohydrate-heavy foods like pasta
Pasta
Pasta is a staple food of traditional Italian cuisine, now of worldwide renown. It takes the form of unleavened dough, made in Italy, mostly of durum wheat , water and sometimes eggs. Pasta comes in a variety of different shapes that serve for both decoration and to act as a carrier for the...
and rice
Rice
Rice is the seed of the monocot plants Oryza sativa or Oryza glaberrima . As a cereal grain, it is the most important staple food for a large part of the world's human population, especially in East Asia, Southeast Asia, South Asia, the Middle East, and the West Indies...
: sales were down 8.2 and 4.6 percent, respectively, in 2003. The diet's success was even blamed for a decline in Krispy Kreme
Krispy Kreme
Krispy Kreme is the name of an international chain of doughnut stores that was founded by Vernon Rudolph in 1937 in Winston-Salem, North Carolina. The parent company of Krispy Kreme is Krispy Kreme Doughnuts, Inc...
sales. Trying to capitalize on the "low-carb craze," many companies released special product lines that were low in carbohydrates. Coca-Cola
Coca-Cola
Coca-Cola is a carbonated soft drink sold in stores, restaurants, and vending machines in more than 200 countries. It is produced by The Coca-Cola Company of Atlanta, Georgia, and is often referred to simply as Coke...
released C2
Coca-Cola C2
Coca-Cola C2 was a cola-flavored beverage introduced by The Coca-Cola Company first in Japan, then later on 7 June 2004 in the United States , in response to the low-carbohydrate diet trend...
and Pepsi-Cola created Pepsi Edge, which was scheduled to be discontinued later in 2005. Unlike the sugar-free soft drinks Diet Coke
Diet Coke
Diet Coke is a sugar-free soft drink produced and distributed by The Coca-Cola Company. It was first introduced in the United States on August 9, 1982, as the first new brand since 1886 to use the Coca-Cola trademark...
and Diet Pepsi
Diet Pepsi
Diet Pepsi is a no-calorie carbonated cola soft drink produced by PepsiCo, introduced in 1964 as a variant of Pepsi-Cola with no sugar. First test marketed in 1963 under the name Patio Diet Cola, it was re-branded as Diet Pepsi the following year, becoming the first diet cola to be distributed on a...
, which had been available for decades, these new drinks used a blend of sugar and artificial sweeteners to offset the flavor of artificial sweetener. These "half-and-half" drinks declined in popularity as soft drink makers learned to use newer sweeteners to mask the flavour of aspartame
Aspartame
Aspartame is an artificial, non-saccharide sweetener used as a sugar substitute in some foods and beverages. In the European Union, it is codified as E951. Aspartame is a methyl ester of the aspartic acid/phenylalanine dipeptide. It was first sold under the brand name NutraSweet; since 2009 it...
(or completely replace it) in reformulated diet drinks such as Coca-Cola Zero
Coca-Cola Zero
Coca-Cola Zero or Coke Zero is a product of the Coca-Cola Company. It is a low-calorie variation of Coca-Cola specifically marketed to males, who were shown to associate 'diet' drinks with women....
and Pepsi ONE
Pepsi ONE
Pepsi ONE is a sugar-free cola, marketed by PepsiCo in the United States as an alternative to regular Pepsi and Diet Pepsi....
.
Low-carbohydrate diets and the societal changes they have caused have been a subject of interest in the news and popular media. For example, on 25 April 2004, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
's Food Network
Food Network Canada
Food Network is a Canadian English language Category A specialty channel with programming related to food, cooking, cuisine, and the food industry. Food Network is a joint venture between Shaw Media, Corus Entertainment, and Scripps Networks Interactive....
aired a one-hour television documentary entitled The Low Carb Revolution.
In 2003, Atkins died from a fatal head injury sustained in a fall on ice. His death came after being affected with some form of cardiomyopathy
Cardiomyopathy
Cardiomyopathy, which literally means "heart muscle disease," is the deterioration of the function of the myocardium for any reason. People with cardiomyopathy are often at risk of arrhythmia or sudden cardiac death or both. Cardiomyopathy can often go undetected, making it especially dangerous to...
(reportedly caused by a viral infection), which had been associated with noticeable weight fluctuation in his final years. This combination of circumstances led to rumors and allegations that Atkins had died from complications arising from his namesake nutritional plan; however, contemporary accounts from his physicians did not substantiate these claims.
On July 31, 2005, the Atkins Nutritional company filed for Chapter 11 bankruptcy protection after the percentage of adults on the diet declined to two percent and sales of Atkins brand product fell steeply in the second half of 2004. The company continues to operate and the diet plan remains popular, although it has not regained its former popularity.
Scientific studies
Because of substantial controversy regarding the Atkins Diet and even disagreements in interpreting the results of specific studies it is difficult to objectively summarize the research in a way that reflects scientific consensus. Although there has been some research done throughout the twentieth century, most directly relevant scientific studies, both those that directly analyze the Atkins Diet and those that analyze similar diets, have occurred in the 1990s and early 2000s and, as such, are relatively new. Researchers and other experts have published articles and studies that run the gamut from promoting the safety and efficacy of the diet to questioning its long-term validity to outright condemning it as dangerous. Until recently a significant criticism of the Atkins Diet was that there were no studies that evaluated the effects of Atkins beyond a few months. However, studies are emerging which evaluate low-carbohydrate diets over much longer periods, controlled studies as long as two years and survey studies as long as two decades.A Swedish prospective study with a follow-up of approximately 10 years came to the conclusion that elderly Swedish men on a carbohydrate-restricted diet (however 40% carbohydrates compared to the Atkins recommended 4%) had a hazard ratio
Hazard ratio
In survival analysis, the hazard ratio is the ratio of the hazard rates corresponding to the conditions described by two sets of explanatory variables. For example, in a drug study, the treated population may die at twice the rate per unit time as the control population. The hazard ratio would be...
of 1.2 for all-cause mortality compared to controls, and a hazard ratio of 1.4 for cardiovascular mortality.
In addition to research on the efficacy of Atkins and other low-carbohydrate diets, some research has directly addressed other areas of health affected by low-carbohydrate diets. For example, contrary to popular belief that low-carbohydrate diets damage the heart, one study found that women eating low-carbohydrate, high-fat/protein diets had the same or slightly less 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...
, compared to women eating high-carbohydrate, low-fat diets. Other studies have found possible benefits to individuals with diabetes, cancer, and epilepsy. Nevertheless some studies demonstrate potentially harmful effects of certain types of low-carbohydrate diets including various metabolic and emotional side-effects.
Controversies
An analysis conducted by Forbes magazineForbes
Forbes is an American publishing and media company. Its flagship publication, the Forbes magazine, is published biweekly. Its primary competitors in the national business magazine category are Fortune, which is also published biweekly, and Business Week...
found that the sample menu from the Atkins Nutritional Approach is one of the top five in the expense category of ten plans Forbes analyzed. This was due to the inclusion of recipes with some high cost ingredients such as lobster tails which were put in the book to demonstrate the variety of foods which could be consumed on the diet. The analysis showed the median average of the ten diets was approximately 50% higher, and Atkins 80% higher, than the American national average. The Atkins diet was less expensive than the Jenny Craig
Jenny Craig
Jenny Craig is an American weight loss guru and founder of Jenny Craig, Inc. Craig was raised in New Orleans and married Sidney Harvey Craig in 1979. In 1983, she and her husband created a nutrition, fitness, and weight loss program in Australia...
diet and more expensive than Weight Watchers
Weight Watchers
Weight Watchers is an international company that offers various dieting products and services to assist weight loss and maintenance. Founded in 1963 by Brooklyn homemaker Jean Nidetch, it operates in about 30 countries around the world, generally under names that are local translations of “Weight...
.
Low-carbohydrate diets have been the subject of heated debate in medical circles for three decades. They are still controversial and only recently has any serious research supported some aspects of Atkins' claims, especially for short-term weight-loss (6 months or less).
In a comparison study by Dansinger and colleagues (2005), the goal was to compare popular diets like Atkins, Ornish, Weight Watchers, and Zone for the amount of weight lost and a heart disease risk reduction. In the study there were 247 individuals and it lasted for 1 year. All the subjects were overweight at baseline, and had an increased risk for cardiac diseases. One of the diets was assigned to each person.
The Atkins diet group ate 20g of CHO (carbohydrate) a day, with a gradual increase toward 50 g daily. The Zone group ate a 40-30-30 % diet of carbohydrates, fats and proteins respectively. The Weight Watchers group was to keep the “points” of their food in a determined range, based on their weight. The Ornish group ate a vegetarian diet with 10% of calories coming from fats.
The weight, waist size, blood pressure, and a blood sample were taken, at the beginning, after 2 months, 6 months and 12 months. All four diets resulted in weight loss with no significant difference between the diets.
But many in the scientific community also raise serious concerns:
- Dr. Robert Eckel of the American Heart AssociationAmerican Heart AssociationThe American Heart Association is a non-profit organization in the United States that fosters appropriate cardiac care in an effort to reduce disability and deaths caused by cardiovascular disease and stroke. It is headquartered in Dallas, Texas...
says that high-protein, low-carbohydrate diets put people at risk of heart disease. A long term study published in the New England Journal of Medicine in 2006 found that while women on low-carb diets were generally healthier than those on high-carbohydrate diets, women eating more protein and fat from vegetable sources, rather than from animal sources, had a lower risk of heart disease. - A 2001 scientific review conducted by Freedman et al. and published in the peer reviewed scientific journal Obesity Research concluded that low-carb dieters' initial advantage in weight loss was a result of increased water loss, and that after the initial period, low-carbohydrate diets produce similar fat loss to other diets with similar caloric intake.
- The May 2004 Annals of Internal Medicine study showed that "minor adverse effects" of diarrhea, general weakness, rashes and muscle cramps "were more frequent in the low-carbohydrate diet group".
- Concerns have been raised regarding consumption of high levels of protein in individuals with medical conditions such as kidney disease or gout.
Opponents of the diet also state that the initial weight loss
Weight loss
Weight loss, in the context of medicine, health or physical fitness, is a reduction of the total body mass, due to a mean loss of fluid, body fat or adipose tissue and/or lean mass, namely bone mineral deposits, muscle, tendon and other connective tissue...
upon starting the diet is a phenomenon common with most diets, and is due to reduction in stored glycogen
Glycogen
Glycogen is a molecule that serves as the secondary long-term energy storage in animal and fungal cells, with the primary energy stores being held in adipose tissue...
and related water in muscles, not fat loss. They say that no evidence has surfaced that any diet will cause weight loss unless it reduces food energy
Food energy
Food energy is the amount of energy obtained from food that is available through cellular respiration.Food energy is expressed in food calories or kilojoules...
(calories) below the maintenance level and that weight loss from the Atkins diet may be the result of less food energy being consumed by the dieter, rather than the lack of carbohydrates. They further point out that weight loss on fad diets
Food faddism
The phrases food faddism and fad diet originally referred to idiosyncratic diets and eating patterns that promote short-term weight loss, usually with no concern for long-term weight maintenance, and enjoy temporary popularity...
, which typically restrict or prohibit certain foods, is often because the dieter has fewer food choices available.
Misconceptions about the diet
Many people believe that the Atkins Diet promotes eating unlimited amounts of fatty meats and cheeses. This is a key point of clarification that Atkins addressed in the more recent revisions of his book. Although the Atkins Diet does not impose caloric restriction, or definite limits on proteins, Atkins points out in his book that this plan is "not a license to gorge." The director of research and education for Atkins Nutritionals, Collette Heimowitz, has said, "The media and opponents of Atkins often sensationalise and simplify the diet as the all-the-steak-you-can-eat diet. This has never been true."Another common misconception arises from confusion between the Induction Phase and rest of the diet. The first two weeks of the Atkins Diet are strict, with only 20g of 'net' carbohydrates permitted per day. Net Carbs are the total carbohydrate content minus the fiber content. The Net Carbs number reflects the grams of carbohydrate that are said to significantly impact blood sugar level and therefore are the only carbs needed to count when doing Atkins. Most of the 20 or less grams of carbohydrates are to come from vegetables.
Atkins states that a dieter can safely stay at the Induction Phase for several months if the person has a lot of weight to lose. Induction, however, is merely a stage to get the body used to fat, and cure cravings for unacceptable foods. Gradually, carbohydrate levels are raised to slow weight loss and add more acceptable foods (berries, more dairy, nuts, etc.), though carbs are still significantly below USDA norms. Once the weight-loss goal is reached, carbohydrate levels are raised again to a state of equilibrium where no weight is lost or gained, which may or may not be below USDA norms, depending on the individual's metabolism, age, and their exercise level.
Atkins Nutritionals
Atkins Nutritionals, Inc. (ANI) was founded in 1989 by Atkins to promote the sale of Atkins-branded products. Following his death, waning popularity of the diet and a reduction in demand for Atkins products, Atkins Nutritionals, Inc. filed for Chapter 11 bankruptcy protection on July 31, 2005 citing losses of $340 million.The company emerged from bankruptcy on January 10, 2006, introducing "a new business strategy that focuses on providing great-tasting portable foods with a unique nutrition advantage to healthy, active men and women." Although the marketing focus has changed, the products are still low-carb. It is also stated on the packages the stage of the Atkins Nutritional Approach where they may be used.
Books
- Eric C. Westman, M.D., Stephen D. Phinney, M.D., and Jeff S. Volek, Ph.D (2010) The New Atkins for a New You: The Ultimate Diet for Shedding Weight and Feeling Great, 350pp, Fireside Books (Simon & Schuster), ISBN 978-1-4391-9027-2
- Robert C. Atkins (2004) Atkins for Life: The Complete Controlled Carb Program for Permanent Weight Loss and Good Health, 370pp, St. Martin's Press, ISBN 0-641-67892-4
- Robert C. Atkins (2001) Dr. Atkins' New Diet Revolution book, 560 pp, Avon Books; Revised ed., ISBN 0-06-001203-X, ISBN 0-09-188948-0
- Robert C. Atkins (2000) Dr. Atkins' Age-Defying Diet Revolution: A Powerful New Dietary Defense Against Aging, Saint Martin's Press, LLC, ISBN 9780312251895
- Robert C. Atkins (1999) Dr. Atkins' Vita-Nutrient Solution: Nature's Answer to Drugs, 416 pp, Fireside Books (Simon & Schuster), ISBN 0-684-84488-5.
See also
- DietDiet (nutrition)In nutrition, diet is the sum of food consumed by a person or other organism. Dietary habits are the habitual decisions an individual or culture makes when choosing what foods to eat. With the word diet, it is often implied the use of specific intake of nutrition for health or weight-management...
- DietingDietingDieting is the practice of eating food in a regulated fashion to achieve or maintain a controlled weight. In most cases dieting is used in combination with physical exercise to lose weight in those who are overweight or obese. Some athletes, however, follow a diet to gain weight...
- 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...
- 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...
- related to Atkins diet - Medical research related to low-carbohydrate dietsMedical research related to low-carbohydrate dietsLow-carbohydrate diets became a major weight loss and health maintenance trend during the late 1990s and early 2000s. While their popularity has waned recently from its peak, they remain popular. This diet trend has stirred major controversies in the medical and nutritional sciences communities...
- Online weight loss plansOnline weight loss plansOnline weight loss plans are web-based fitness programs designed to help participants lose weight. They usually include assistance in the areas necessary for weight loss. For example, weight loss information, goal setting, progress tracking, meal and workout planning, and personal support from...
- Dukan DietDukan DietThe Dukan Diet is one of the most popular diet plans in France. It is a protein-based diet designed by French nutritionist and dietician, Pierre Dukan. Although Dukan has been promoting his diet for over 30 years, its popularity has grown since 2000. His book The Dukan Diet is a best seller in...
External links
- Official Atkins Corporate Site
- New England Journal of Medicine: (vol 348, p 2082) A randomized trial of a low-carbohydrate diet for obesity.
- New England Journal of Medicine: (vol 359, p 229) Weight Loss with a Low-Carbohydrate, Mediterranean, or Low-Fat Diet (July 17, 2008)
- Everything Atkins Diet Information, Tips & Resources