Atkins Diet

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.

Dr Atkins' New Diet Revolution book

Nature of the diet

A balanced meal according to the Atkins diet

The Atkins diet involves limited consumption of carbohydrates to switch the body's metabolism 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.)^[1] 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".^[2] He cited one study where he estimated this advantage to be 950 calories (4.0 MJ) per day. A review study published in Lancet^[3] 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.^[2]

Net carbohydrates can be calculated from a food source by subtracting fiber and sugar alcohols (which are shown to have a smaller effect on blood sugar levels)^{[citation needed]} 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.^[4] Fructose (for example, as found in many industrial sweeteners) has four calories per gram but has a very low glycemic index^[5] and does not cause insulin production, probably because β cells have low levels of GLUT5.^[6][7] 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.^[8]

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.^[9]

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.^[10] 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 diet. In ketogenic diets there is production of ketones that contribute to the energy production in the Krebs cycle.^[11] 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 (64.5 mg/dl) for growth hormone, epinephrine, and glucagon to be released to maintain energy metabolism.^[11] 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.^[11] 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.^[11]

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.^[12] 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.^[13]

Cholesterol

According to Harper (2004) in a year-long study, the concentration of high-density lipoprotein (HDL) cholesterol 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.^[14][15]

Methylglyoxal

A 2005 study by Beisswenger and colleagues compared levels of the glycotoxin methylglyoxal (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).^[16]

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.^[17]

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 ketosis. Carbohydrate intake is limited to less than 20 net grams per day (grams of carbohydrates minus grams of fiber, sugar alcohols, 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.^[18] 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.^[18] A daily multivitamin with minerals, except iron^{[citation needed]}, 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^{[citation needed]}. 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 the sweet smell of ketones on breath.^[2]

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. 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 produce. 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 ketosis on a testing stick. As a result, it is not necessary to maintain a positive ketosis test long term.

You may be able to add some of the forbidden carbs back into your diet once a week. In this phase your body is beginning to lose the protection of ketosis. You are preparing for the last phase which is Lifetime Maintenance.

Drink at least eight glasses of water per day.

Increase your daily carb count by 10 grams each week as long as you continue to lose your weight. If you are at your goal weight, stay at that level for a month or so before you increase your daily carb consumption by another 10 grams to see if you can consume that level without gaining. Once you do begin to gain, drop back 10 grams.

This phase can last several weeks until You find Your tipping point.

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.

Make weight control a priority. Weigh yourself at least once per week, and select a healthy weight range that works for you.

Popularity

The Atkins Nutritional Approach gained widespread popularity in 2003 and 2004. At the height of its popularity one in eleven North American adults was on the diet.^[19] 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.^[20] 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.^[21] 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.^{[22][23][24][25]}

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.^[26][27] Although there has been some research done throughout the twentieth century,^[28][29] 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^[30][31] to questioning its long-term validity^[32][33] to outright condemning it as dangerous.^[34][35] 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.^{[30][36][37][38]}

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.^[39]

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.^[40] Other studies have found possible benefits to individuals with diabetes,^[41] cancer,^[42][43] and epilepsy.^[44][45] Nevertheless some studies demonstrate potentially harmful effects of certain types of low-carbohydrate diets including various metabolic and emotional side-effects.^[46]

A 2007 study done at Stanford University Medical School, The A to Z Weight Loss Study, compared the Atkins diet with the Zone, Ornish, and LEARN diets in a randomized group of 311 obese premenopausal women over a period of 12 months. The study found that weight loss was significantly higher for the Atkins diet compared to the other three diets. Secondary factors such as HDL-C, triglyceride levels, and systolic blood pressure were also found to have improved to greater levels compared to the other diets.^[47]

Controversies

An analysis conducted by Forbes magazine 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.^[48]

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.^[49] The Atkins diet group ate 20g of CHO (carbohydrate) a day, with a gradual increase toward 50 g daily. But according to Table 2 of the study, increased to well over 130g after the second month and up do 190g by the sixth month. At this point, the Atkins diet group were eating carbohydrates equivalent to the other three groups. 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.^[49]

But many in the scientific community also raise serious concerns:

• Dr. Robert Eckel of the American Heart Association says that high-protein, low-carbohydrate diets put people at risk of heart disease.^[50] 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.^[51]
• 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.^[52]
• 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.^{[citation needed]}

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.^[53] 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.^{[citation needed]}

Misconceptions about the diet

Many people believe that the Atkins Diet promotes eating unlimited amounts of fatty meats and cheeses.^[54][55] 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 says 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".^[9]

Another common misconception arises from confusion between the Induction Phase and rest of the diet.^[55] 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.^[56] 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.

Dr. Eric Westman, director of the Duke University's Lifestyle Medicine Clinic and co-author of "The New Atkins for a New You," believes low-carb or Atkins should be viable options among diets.

"The Atkins diet was labeled as a high-fat diet," Westman said in an interview with The New York Times. "We've been told over the past 40 years that fat in the diet is bad. Now we know that fat is not bad. What's happened is that there is a paradigm shift in thinking about carbohydrates, fat and protein and health."

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.^[57] 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."^[58] 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 978-0-312-25189-5
• 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

• Diet
• Dieting
• Low-carbohydrate diet
• Ketogenic diet - related to Atkins diet
• Medical research related to low-carbohydrate diets
• Online weight loss plans
• Dukan Diet

References

External links

Wikibooks Cookbook has a recipe/module on Atkins Diet Cooking

• Official Atkins Corporate Site
• Atkins diet at the Open Directory Project
• 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)