The Atkins diet was produced by Dr. Robert Atkins in the 1960s and became widely known in the 1970s with the release of some books describing Atkins’s theories. Recently, the Atkins franchise and the Atkins symbol have been applied to many different products. The theory is based on the concepts that the main reason behind obesity could be the consumption of refined carbohydrates, such as for example sugar, flour, and corn syrups, and that the consumption of dietary fat does not necessarily subscribe to obesity. In this diet, the restriction of carbohydrates induces circumstances of ketosis in which your body begins to break up fat stores instead of using glucose supply for energy. Atkins described four phases of his diet: induction, ongoing weight loss, premaintenance, and lifetime maintenance. In the induction phase, carbohydrate intake is strictly restricted to 20 net grams per day (“net” carbohydrates are described as those that contribute to sugar levels, which excludes fiber and sugar alcohols). In the ongoing weight loss phase, a growth in carbohydrate intake is allowed, but still below an amount which allows continued weight loss. Carbohydrate intake is further increased in the premaintenance phase, which can be above a level that induces ketosis.
The lifetime maintenance phase stresses long-term adherence to these principles of carbohydrate restriction and a come back to earlier, more restrictive phases if weight gain occurs. One of the largest randomized trials, conducted by Gardner et al90 at Stanford University, has found the dietary plan to create a greater weight loss over an amount of 12 months as in contrast to other popular diets. Low-carbohydrate ketogenic diets, like the Atkins diet, have now been shown to have a greater improvement on subjective symptoms, including mood changes and the impression of hunger, as compared with low-fat diets.91 A study conducted by the Centers for Disease Control and Prevention shows that the diet is relatively well tolerated, with approximately 40% of male users and 30% of female users reporting long-term usage of the dietary plan (longer than12 months).92 A study by Dansinger et al93 at Tufts–New England Medical Center showed a mean weight reduction of 2.1 kg in patients adhering to the Atkins diet over a 1-year period, with 53% of patients remaining compliant through that time. Animal studies have demonstrated significant changes in metabolism caused by a ketogenic diet, correlating changes in gene expression to weight loss, improved glucose tolerance, and increased energy expenditure.94 Concerns have now been raised over possible detrimental consequences of the diet on overall nutritional balance and health with prolonged use. Some studies have suggested a growth in mortality in patients adhering to this diet.95–97 Particular concern has been expressed over increases in cardiovascular risk and mortality that may be attributable to the fat intake and carbohydrate restriction.95,96 Studies by Rankin and Turpyn98 have described a positive correlation between increasing C-reactive protein levels and a low-carbohydrate, high-fat diet, which will be indicative of a systemic inflammatory state. Effects on neurotransmitter metabolism have been postulated, as a ketogenic diet has been proven to be beneficial in seizure prophylaxis in epileptic children.99 Despite such metabolic changes, there remains a paucity of data to aid maintenance of weight loss for longer than 12 months from the low-carbohydrate, ketogenic diet.