|
|
__ |
|
|
The Atkins Nutritional Approach, popularly known as the Atkins Diet or just Atkins, is the most marketed and well-known low-carbohydrate diet. It was adapted by Dr. Robert Atkins in the 1960s from a diet he read in the Journal of the American Medical Association and utilized to resolve his own overweight condition following medical school and graduate medical training. After successfully treating over ten thousand patients, he popularized the Atkins diet in a series of books, starting with Dr. Atkins' Diet Revolution in 1972. In his revised book, Dr. Atkins' New Diet Revolution, Atkins updated some of his ideas, but remained faithful to the original concepts. The Atkins franchise, a business formed to provide products to those individuals on the diet, has been highly successful due to the popularity of the diet, and is considered the iconic and driving entity of the larger "low-carb craze". However, various factors have led to its dwindling success and the company founded by Dr. Atkins in 1989, Atkins Nutritionals of Ronkonkoma, New York, filed for Chapter 11 bankruptcy in July of 2005, two years after the death of Dr. Atkins. The company re-emerged in January 2006, and the Atkins logo is still highly visible through licensed-proprietary branding for food products and related merchandise. Nature
of the diet
The Atkins Diet represents a departure from prevailing theories. Atkins claimed there are two main unrecognized factors about Western eating habits, arguing firstly that the main cause of obesity is eating refined carbohydrates, particularly sugar, flour, and high-fructose corn syrups; and secondly, that saturated fat is overrated as a nutritional problem, and that only trans fats from sources such as hydrogenated oils need to be avoided. Consequently, Dr. Atkins rejected the advice of the food pyramid, instead asserting that the tremendous increase in refined carbohydrates is responsible for the rise in metabolic disorders of the 20th century, and that the focus on the detrimental effects of dietary fat has actually contributed to the obesity problem by increasing the proportion of insulin-inducing foods in the diet. While most of the emphasis in Atkins is on the diet, nutritional supplements and exercise are considered equally important elements. Atkins involves the restriction of carbohydrates in order to switch the body's metabolism from burning glucose to burning stored body fat. This process (called lipolysis) begins when the body enters the state of ketosis as a consequence of running out of excess carbohydrates to burn. Dr. Atkins in his book New Diet Revolution claimed that the low-carbohydrate diet produces a "metabolic advantage" where the body burns more calories, overall, than on normal diets, and also expels some unused calories. He cited one study where he estimated this advantage to be 950 calories (4.0 MJ) a day. The Atkins diet restricts "net carbs", or carbohydrates that have an effect on blood sugar. The effect is to decrease the onset of hunger from low blood sugar. Dr. Atkins says in Dr. Atkins' New Diet Revolution (2002) that hunger is the number one reason why low-fat diets fail. Though studies show the efficacy of the Atkins approach after one year is the same as a low-fat diet, Dr. Atkins claimed that it was easier to stay on the Atkins diet because dieters did not feel hungry or "deprived". Net carbohydrates can be calculated from a food source by subtracting sugar alcohols and fiber (which are shown to have a negligible effect on blood sugar levels) from total carbohydrates. Sugar alcohols need to be treated with caution, because while they may be slower to convert to glucose, they can be a significant source of glycemic load and can stall weight loss. Fructose (eg, as found in many industrial sweeteners) also contributes to caloric intake, though outside of the glucose-insulin control loop. Preferred foods in all categories are whole, unprocessed foods with a low glycemic load. Atkins Nutritionals, the company responsible for marketing the Atkins Diet, recommends that no more than 20% of calories eaten while on the diet come from saturated fat.[1] According to his book Atkins Diabetes Revolution, for people whose blood sugar is abnormally high or who have type-2 diabetes, this 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.[2] Phases There are four phases of the Atkins diet: induction, ongoing weight loss, pre-maintenance and lifetime maintenance. Induction The Induction phase is the first, and most restrictive, phase of the Atkins Nutritional Approach. It is intended to cause the body to quickly enter a state of ketosis. Carbohydrate intake is limited to 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 vegetables. The allowed foods include a liberal amount of all meats, fish, shellfish, fowl, and eggs; up to 4 ounces (113 g) of soft or semi-soft cheese; salad vegetables; other low carbohydrate vegetables; and butter and vegetable oils. Alcoholic beverages are not allowed during this phase.[3] 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.[3] A daily multivitamin with minerals is also recommended. 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. Atkins suggests the use of Ketostix, small chemically reactive strips used by diabetics. These let the dieter monitor when they enter the ketosis, or fat burning, phase. Other indicators of ketosis include a metallic taste in the mouth, or bad breath. 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. At first weeks you should add more of the induction acceptable vegetables to your daily products. For example, 6-8 stalks of asparagus, salad, one cup of cauliflower or one half of avocado. The next week you should follow the carbohydrate ladder 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:
Pre-maintenanceCarbohydrate intake is increased again this time by 10 net carbs a week from the ladder 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. Lifetime maintenanceThis 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-American adults were on the diet [1]. 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 [2]). The diet's success was even blamed for a decline in Krispy Kreme sales [3]. 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 traditional sweetener and the diet drinks' artificial sweeteners to offset the allegedly inferior artificial sweetener flavor. These "half-and-half" drinks declined in popularity as soft drink makers learned to use newer sweeteners to mask the flavor of aspartame (or completely replace it) in reformulated diet drinks such as Coca-Cola Zero and Pepsi ONE. Robert Atkins died from a fatal head injury sustained in a fall on ice in 2003. The nutritional plan suffered from rumors and allegations that he was obese at the time and had died from a heart condition as a result. 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 Low Carb Revolution was a one-hour documentary television special on the Atkins diet. The special, which aired on Food Network Canada, on April 25, 2004, described how this diet works, had success stories, and quickly presented some recipes. Scientific Studies Several randomized, controlled studies, published in peer-reviewed journals, have concluded that dieters on the Atkins diet have achieved weight loss comparable to or greater than other diets, up to 1 year. Blood lipids have also improved, and no serious adverse effects have been observed. There are no rigorous studies to show the results after 1 year. In a controlled study, published in JAMA (March 7, 2007), by Gardner at Stanford University, women "lost more weight and experienced more favorable overall metabolic effects at 12 months" than in other diets. The study followed 311 premenopausal, nondiabetic women, age 25-50. The women lost more weight (mean 4.7 kg) on the Atkins diet than on 3 higher-carbohydrate diets (LEARN 2.6 kg, Ornish 2.2 kg, and Zone 1.6 kg), without increasing cardiovascular risks. Changes in HDL cholesterol, triglycerides, and mean blood pressure significantly favored Atkins over the other three diets. The authors conclude: "Concerns about adverse metabolic effects of the Atkins diet were not substantiated within the 12-month study period."[4] When the Atkins diet was introduced in the 1970s, it was immediately attacked by existing experts, who claimed it was unhealthy and would fail. For example, Atkins testified before the Senate Select Committee on Nutrition and Human Needs, in April, 1973. That day, "three authorities in nutrition and health ... [testified] that Atkins's severely carbohydrate-restricted diet was neither revolutionary, effective, or safe," and a comment by Harvard nutritionist Fred Stare was read into the record: "The Atkins diet is nonsense.... Any book that recommends unlimited amounts of meat, butter and eggs, as this does, in my opinion is dangerous. The author who makes the suggestion is guilty of malpractice."[5] Subsequent studies have not supported those fears
The strongest evidence is randomized, controlled studies published in peer-reviewed journals. The greater the number of subjects, and the longer the subjects are followed, the more powerful the study. To date, the longest studies are 1 year, so the effects of the diet over longer durations are not known. The medical principles and scientific theory behind the Atkins diet were first explainedin a series of articles by Dr. Richard D. Feinman, a professor of biochemistry and medical researcher at State University of New York (SUNY) Health Science Center (Downstate) at Brooklyn. Feinman, president of the Nutrition & Metabolism Society, published work which attempts to prove the common idea that "a calorie is a calorie" is not correct. His research aims to demonstrate why the diet is nutritionally sound and to elucidate principles which prove Atkins scientifically correct Proponents of the Atkins diet feel much of the criticism leveled at the diet comes from statements and opinions of individuals and associations, rather than from controlled and reviewed studies.. Advocates of the diet dispute criticisms, such as the fact that a low-carbohydrate diet is likely to be high-fat and allegations that fat, especially saturated fat, is harmful. Atkins backers maintain that, unlike trans fat, which can result from partial hydrogenation, fully saturated fat is not harmful. Proponents cite the award-winning science writer Gary Taubes who, in a 2001 article in Science, 291 (5513): 2536, claimed that the oft-cited "consensus" opinion against saturated fats derives from political rather than scientific motives. Taubes' 2007 book Good Calories, Bad Calories: Challenging the Conventional Wisdom on Diet, Weight Control, and Disease also makes this point, but in more depth. Taubes reviews the nutrition research of a century from various angles, and draws his conclusion from a very diverse set of evidence Critics of the Atkins diet may focus particularly on Atkins, or on low-carbohydrate dieting in general. Proponents claim that critics fail to consider that people are built differently, and as with any diet, the Atkins Nutritional Approach may not be effective for some people. Continuing research supports the idea that saturated fat may be cardio-protective in some populations.[8][9] The May 22, 2003, issue of the New England Journal of Medicine published two scientific, randomized studies comparing standard low-fat diets to low-carbohydrate diets such as the Atkins Diet. In both studies, subjects lost more weight on the low-carbohydrate plans at 6-months but not at 1-year. The editors noted that "Adherence was poor and attrition was high in both groups. Longer and larger studies are required to determine the long-term safety and efficacy of low-carbohydrate, high-protein, high-fat diets."[10]
Controversy
It is a common
misconception that meat with high fat is a typical meal in the
Atkins diet. The actual goal of Atkins dieters is to avoid high
glycemic index foods such as soft drinks, fruit juice and potatoes.
Atkins dieters can still eat a variety of food such as salads,
cheese, and lean meats.
An analysis conducted by Forbes magazine found that the boxed retail Atkins Nutritional Approach food product is one of the top five in the expense category of ten plans Forbes analyzed. The analysis showed the median average of the ten diets was approximately 50% higher, and Atkins 80% higher, than the American national average. Atkins was less expensive than Jenny Craig and more expensive than Weight Watchers.[13] 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). But many in the scientific community also raise serious concerns:
Opponents of the diet also point out 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 claim that no evidence has surfaced that any diet will cause weight loss unless it reduces food energy (calories) below the maintenance level, and reports have indicated that successful weight loss due to the Atkins diet may be the result of less food energy being consumed by the dieter, rather than the lack of carbohydrates.[16] They further point out that weight loss on fad diets, which typically restrict or prohibit certain foods, is often due to the fact that the dieter has fewer food choices available. On May 27, 2004, Jody Gorran, a 53-year-old Florida businessman with a family history of heart disease, filed a lawsuit, aided by the Physicians Committee for Responsible Medicine, a PETA front group, in federal district court against Atkins Nutritionals, Inc. and the estate of Dr. Robert Atkins, claiming that the Atkins diet regimen caused severe heart disease, making it necessary for him to undergo angioplasty. He sought a court injunction banning Atkins Nutritionals from marketing its products without a warning of potential health risks, and asked for compensatory damages. Gorran's complaint was dismissed by the court in December 2006 as being meritless, with the court stating, "Defendants' books and food products are not defective or dangerous products within the meaning of products liability law."[17] Misconceptions about the diet Many people incorrectly believe that the Atkins Diet promotes eating unlimited amounts of fatty meats and cheeses. This is a key point of clarification that Dr. Atkins addressed in the more recent revisions of his book. Although the Atkins Diet does not impose limits on certain foods, or caloric restriction in general, Dr. 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."[1] 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 carbohydrates permitted per day. 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.[18] Once the weight-loss goal is reached, carbohydrate levels are raised gradually, though still significantly below USDA norms, and still within or slightly above the definition of ketosis. The Induction Phase is also known for its comparatively lower intake of dietary fiber, and this is often misconstrued as characteristic of the diet as a whole. In fact fiber supplements, such as psyllium seed husks, are recommended for the early stages. It is often misstated that those on the diet do not consume enough vegetables and fruits. However those who follow it properly should not face this problem as even the Induction Phase allows for adequate amounts of dark green leafy vegetables. Atkins Nutritionals Atkins Nutritionals, Inc. (ANI) was founded in 1989 by Dr. Robert Atkins to promote the diet and sell 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.[19] 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."[20] 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
References
External links
|
| All text is available under the terms of the GNU Free Documentation License (see Copyrights for details). Disclaimers. Wikipedia is powered by MediaWiki, an open source wiki engine. |
| Questions
or Comments? |