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:
- Induction acceptable vegetables
- Fresh dairy
- Other fruits
- Starchy vegetables
Carbohydrate 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.
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.
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. This large following was blamed for large declines in the sales of carb-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 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 (with commercials) 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.
An analysis conducted by Forbes magazine found that the Atkins Nutritional Approach (the boxed retail food product created by Atkins to facilitate the Atkins diet) is one of the five most expensive diet plans of the ten plans Forbes analyzed. Although Forbes found that Atkins diet was significantly less expensive than Jenny Craig and only slightly more expensive than Weight Watchers, the Atkins diet nevertheless involved more than an 80% premium over average American food expenses.
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:
- Dr. Robert Eckel of the American Heart Association says that high-protein, low-carbohydrate diets put people at risk of heart disease; however, a long term study published in the New England Journal of Medicine in 2006 found that women reduced heart disease risk by eating more protein and fat from vegetable sources.
- A 2001 scientific review by Obesity Research magazine concluded that low-carb dieters' initial advantage in weight loss was a result of increased water loss, and that after the initial period, low-carb diets produce similar fat loss to other diets with similar caloric intake.
- The May 2004 Annals of Internal Medicine study showed that Atkins Dieters had significantly more diarrhea, general weakness, rashes and muscle cramps. Atkins.com now suggests a fiber supplement.
- Also, acidity from the typically high protein intake can cause Osteoporosis.
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. 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. Also, a diet of low-carb foods may quickly become dull to many people, meaning that their appetite is somewhat naturally suppressed as they become hungry for carbs, but the dieter either has none handy or resists this hunger.
It is claimed that there is bad breath and fatigue under the Atkins diet: and Cleveland Clinic Journal of Medicine 68(2001): p.761. The presence of acetone in the breath of an Atkins dieter may indeed be detectable during ketosis, and in fact, quantitative measurement of acetone concentration in exhalation is a reliable indicator of ketosis.
On May 27, 2004, Jody Gorran, a 53-year-old Florida businessman with a family history of heart disease, filed a lawsuit 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 asking 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."
The Physicians Committee for Responsible Medicine, a PETA-connected, anti-meat eating organization which is opposed to the Atkins diet, states that in East Asian countries such as Thailand or Japan, the average person's diet consists of mainly carbohydrates such as rice and noodles, yet these groups have very low rates of obesity. If so, this may contradict Atkins' claim that high levels of carbohydrate consumption cause obesity, although studies show that obesity is increasing in Asia. In addition, coronary heart disease is much less prevalent in Asia.
Evidence in favor of the diet
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 the largest, most recent randomized, 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 significantly 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."
When the Atkins diet was introduced in the 1970s, it was immediately attacked by existing experts, who claimed it was unhealthy and would fail. Subsequent studies have not supported those fears:
- "The low-carbohydrate diet produced a greater weight loss for the first six months, but the differences were not significant at one year. The low-carbohydrate diet was associated with a greater improvement in some risk factors for coronary heart disease. 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." â€” New England Journal Of Medicine, Volume 348:2082-2090, 22 May 2003, Number 21
- "better participant retention and greater weight loss...greater decreases in serum triglyceride levels" â€” Annals Of Internal Medicine, 18 May 2004 | Volume 140 Issue 10 | Pages 769-777 (Journal Editor's note: "While the study suggests the efficacy and relative safety of the low-cholesterol diet, the high dropout rate, self-directed adherence to the diet, and relatively short observation period challenge the generalizability of the findings.")
- "sustained weight loss (at 6 months)" â€” Atkins funded, non-randomized, non-control intervention trial, American Journal of Medicine, Volume 113, Issue 1, July 2002, Pages 30-36.
- "When carbohydrates were restricted (during a 2-week study on 10 obese Patients with Type 2 Diabetes), study subjects spontaneously reduced their caloric intake to a level appropriate for their height, did not compensate by eating more protein or fat, and lost weight. We concluded that excessive overeating had been fueled by carbohydrates." "In addition to the calorie reduction and weight loss, subjects experienced markedly improved glucose levels and insulin sensitivity, as well as lower triglycerides and cholesterol." This is not a controlled study in that there was no control group; it merely observed the effect of putting ten obese diabetics on the Atkins diet; this is "the only study of the Atkins diet to have been conducted in the strictly controlled environment of a clinical research center where every calorie eaten and spent was measured." â€” Annals of Internal Medicine, 15 March 2005.
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.
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 based on the fact that a low-carb diet is likely to be high-fat and allegations that fat, especially saturated fat, is harmful. Atkins backers maintain that, aside from trans fat, saturated fat is not harmful. Proponents cite Gary Taubes who, in a 2001 article in Science, 291 (5513): 2536, claims that the oft-cited "consensus" opinion against saturated fats derives from political rather than scientific motives.
Critics of the Atkins diet may focus particularly on Atkins, or on low-carb dieting in general. Proponents claim that critics fail to consider that people are built differently, and as with any diet, the Atkins may not be effective for some people.
Continuing research supports the idea that saturated fat may be cardio-protective in some populations, see http://www.ajcn.org/cgi/content/abstract/80/5/1175, "Dietary fats, carbohydrate, and progression of coronary atherosclerosis in postmenopausal women" and http://www.ajcn.org/cgi/content/full/80/5/1102 , "Saturated fat prevents coronary artery disease? An American paradox."
The 22 May 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."
A research study carried out by the Weight and Eating Disorders Program at the University of Pennsylvania, reported in May 2003 that the Atkins diet raised levels of HDL (or "good") cholesterol by an average of 11% and reduced the amount of triglycerides in the bloodstream by 17%. This counters one of the chief criticisms of Atkins' approach, which is that cholesterol is raised by eating fatty foods and meat.
In another study, conventional dieters' HDL cholesterol raised by 1.6% while their triglyceride levels improved. Weight loss was also statistically greater in the Atkins dieters after three and six months compared with the conventional dieters (although this did not remain statistically significant after a year). The study followed the diets of 63 obese men and women. (See New Scientist, 21 May 2003.)
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."
Some criticism of the diet seems to be based on a confusion between ketosis and ketoacidosis. Ketosis is short for Benign Dietary Ketosis, which is a normal metabolic process that results when glucose is not available as a source of energy. The body then burns mostly fat, both directly and through conversion to ketones which make the energy of fat available in water soluble form. Ketoacidosis is a metabolic crisis due to the inability to utilize glucose because of a lack of insulin and in which there is an abnormal accumulation of ketones exacerbated by severe dehydration as the kidneys spill the useless glucose, losing water in the process. This occurs in diabetics, in a related form in alcoholics, and also in starvation.
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 claims that a dieter can safely stay at the Induction Phase for several months if the person has a lot of weight to lose. 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 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, for example. Many people who try Atkins have reported eating more vegetables while on the plan than they ever did before.
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