In Dr. Robert Atkins revised book, Dr. Atkins' New Diet Revolution, Atkins updated some of his ideas, but remained faithful to the original concepts.

The Atkins franchise (i.e., the business formed to provide products serving people "doing Atkins") had been highly successful due to the popularity of the atkins diet, and is considered the iconic and driving entity of the larger "low-carb craze". 

Nature of the atkins diet

The Atkins Diet represents a radical 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 rejects 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.

Dr. Atkins argued that many eating disorders are the result of hyperinsulinism, or excessive secretion of insulin which comes through eating too many carbohydrates. According to Dr. Atkins, this causes food cravings and unstable blood sugar levels, which can cause mood swings, depression, and sleeping problems. He claimed that the atkins diet stabilizes insulin and blood sugar levels, eliminating cravings and often reducing appetite.

While most of the emphasis in Atkins is on the diet, nutritional supplements and exercise are considered equally important elements.

Atkins involves restriction of the intake of carbohydrates in order to switch the body's metabolism from burning glucose to burning fat (chiefly, stored fat). This process (called lipolysis) begins when the body enters the state of ketosis as a consequence of running out of carbohydrates to burn.

Atkins restricts "net carbs", or carbs that have an effect on blood sugar. 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.

Preferred foods in all categories are whole, unprocessed foods with a low glycemic load.

Phases of the dietThere are four phases of the Atkins diet.

InductionThe Induction phase is the first, and most restrictive, phase of the Atkins diet. It is intended to cause the body to quickly enter a state of ketosis. Carbohydrate intake is limited to 20 net grams per day. The allowed foods include a liberal amount of most meats, a good bit of cheese and cream, two cups of salad, and one cup of other vegetables. Caffeine and alcoholic beverages are not allowed.

The Induction Phase of the atkins diet is usually when many see the most significant weight loss - reports of losses up to six or eight pounds (3 or 4 kg) per week are not uncommon.

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.

Ongoing weight loss

The Ongoing Weight Loss (OWL) phase of the Atkins diet consists of an increase in carbohydrate intake, but remaining at levels where weight loss occurs. Carb intake increases by 5 grams of carbs per day each week. A goal in OWL is to find the "Critical Carbohydrate Level for Losing". The OWL phase lasts until weight is within 10 pounds (4.5 kg) of the target weight.

Pre-maintenance

Carbohydrate intake is increased again, 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. So it is not necessary to maintain ketosis forever.

Lifetime maintenanceThis phase of the atkins diet 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 emphasised, with the option to drop back to an earlier phase if you begin to gain weight.

PopularityThe Atkins Nutritional Approach (atkins diet) gained widespread popularity in 2003 and 2004. At the height of its popularity one in eleven adults were on the atkins diet. The popularity of the diet was so great that the sales of popular foods that are high in carbs actually decreased and the atkins diet was blamed. Trying to capitalize on the "low-carb craze" many companies released special product lines which were low in carbohydrates. 

For more information on the atkins diet visithttp://en.wikipedia.org/wiki/Atkins_diet