The Medical Letter

Dr. Atkins Diet Revolution The Medical Letter on Drugs and Therapeutics 15(1973):41 The Medical Letter on Drugs and Therapeutics 15(1973):41

The Medical Letter on Drugs and Therapeutics started publication in 1959. The Medical Letter is an independent, peer-reviewed, nonprofit publication that offers unbiased critical evaluations of drugs, with special emphasis on new drugs, to physicians and other members of the health professions. It is published in five languages and has a circulation of more than 120,000.

“Dr. Atkins’ Diet Revolution, The High Calorie Way to Stay Thin Forever” (New York:McKay, 1972) promotes a low-carbohydrate diet for weight reduction. The Atkins diet is not new or revolutionary; it is similar to one described by W. Banting as far back as 1863 and advocated recently in “The Drinking Man’s Diet” (G. Jameson and E. Williams, San Francisco:Cameron, 1964) and “Calories Don’t Count” (H. Taller, New York:Simon and Schuster, 1961). The diet advocated by Dr. Atkins at first excludes virtually all carbohydrate and later permits a gradual increase to no more than 40 Cm per day. It is a diet designed to produce ketosis, with the degree of ketonuria to be monitored by the patient with a dip stick test of the urine.

THE DIET - The Atkins diet allows an unrestricted intake of calories derived from protein and fat, and encourages a high intake of saturated fats and cholesterol-rich foods. Among the claims made or strongly implied in the At kins book are that overweight subjects can consume 5,000 calories or more and still lose weight;, that on such a diet many calories are lost daily in the urine and breath as ketones and other incompletely oxidized metabolites; that the diet stimulates secretion of a “fat mobilizing hormone;” that the mobilized fat is readily converted to carbohydrate, thereby keeping the blood sugar “… at an even level.”

Atkins describes carbohydrate as a “poison” and sugar as an “antinutrient.” He also subscribes to the belief that reactive hypoglycemia is widespread and generally undiagnosed in the United States. Atkins gives no references to studies establishing the long-term effectiveness and safety of his diet.

EVALUATION - J. Yudkin and C. W. Carey (Lancet, 2:939, I960) showed that obese subjects whose dietary carbohydrate intake is rigidly restricted do not increase their intake of protein and fat proportionately. Thus, they lose weight simply by consuming far fewer calories than usual. The ketosis and inhibition of gastric emptying induced by a low-carbohydrate, high-fat diet may help to suppress hunger pangs, which could explain why such a diet helps some individuals to lose weight. If the obese subject on the Atkins diet consumes enough protein and fat to compensate for the calories lost by carbohydrate restriction, there is no reason to believe that he will lose weight. Ketones in urine and breath rarely, if ever, account for more than 100 calories per day. The existence of a fat mobilizing hormone has never been confirmed; moreover, there is no appreciable net synthesis of carbohydrate from fatty acids in man. Reactive hypoglycemia is a bona-fide syndrome but it is not remotely as prevalent as Atkins suggests (Medical Letter, Vol. 14, p. 7, 1972). Patients on a low-carbohydrate ketogenic diet do usually exhibit a transient sodium and water diuresis, which causes some weight loss, but as the diet is continued sodium and water excretion returns to normal.

ADVERSE EFFECTS - Most diets that promote ketosis are likely to produce fatigue, dehydration and, in some instances, nausea and vomiting, especially in persons who attempt to remain physically active. Atkins’ diet may cause an appreciable hyperuricemia, which can precipitate an attack of gout. The starvation-like state induced by a low-carbohydrate, ketogenic diet stimulates release of free fatty acids into the plasma; in patients with cardiovascular disorders such as cerebrovascular and coronary artery disease, increased free fatty acids may induce cardiac arrhythmias (M. F. Oliver et al.. Lancet, 1:710, 1968). Pregnant women should avoid the Atkins diet because chronic ketosis in the mother could adversely affect the fetus. (The Council on Foods and Nutrition of the American Medical Association will soon publish a statement on the Atkins diet in the JAMA.)

CONCLUSION - Although it may be effective in some patients, the Atkins diet is unbalanced, unsound, and unsafe.