The Atkins Diet is a high-protein, low-carbohydrate weight-loss diet developed by
Robert Atkins, MD. Atkins dieters can eat as many calories from protein and fat as they want,
as long as they restrict their carbohydrates.
The diet is divided into four phases:
Induction (the first 14 days)—Carbs are limited to no more than 20 grams
per day. No fruit, bread, grains, starchy vegetables, or dairy products (except cheese, cream,
and butter) are allowed during this phase.
Ongoing weight loss—Dieters experiment until they find a carbohydrate
intake that allows them to continue to lose weight until their weight-loss goals are met.
Premaintenance and maintenance—Dieters determine the level of carbohydrate
intake that allows them to maintain their weight.
Best bets: Meats, eggs, dairy products (except milk), Atkins-labeled products, or
check the nutrition label to see the carb content for any food. See our Low-Carbohydrate Diet article for more low-carb
More about this diet
Originally developed in the 1960s, in the early 1990s Dr. Atkins brought his diet back into
the nutrition spotlight with the publication of his best-selling book Dr. Atkins’
New Diet Revolution.
The Atkins Diet severely restricts the consumption of carbohydrate-rich foods and
encourages the consumption of protein and fat. The diet is divided into four phases:
Induction, Ongoing Weight Loss, Premaintenance, and Maintenance. During the Induction phase
(the first 14 days of the diet), carbohydrate intake is limited to no more than 20 grams per
day. No fruit, bread,
grains, starchy vegetables, or dairy products (except cheese,
cream, and butter) are allowed during this
phase. During the Ongoing Weight Loss phase, dieters experiment with various levels of
carbohydrate consumption until they determine the most liberal level of carbohydrate intake
that allows them to continue to lose weight. Dieters are encouraged to maintain this level of
carbohydrate intake until their weight loss goals are met. During the Premaintenance and
Maintenance phases, dieters determine the level of carbohydrate consumption that allows them
to maintain their weight. To prevent weight regain, dieters are told to maintain this level of
carbohydrate consumption, perhaps for the rest of their lives. According to Dr. Atkins, most
people must limit their carbohydrate intake to no more than 60 grams per day to keep lost
Note: The dietary recommendations issued by various organizations, including the
United States Department of Agriculture, the National Institutes of Health, and the American
Heart Association, encourage a daily carbohydrate intake of approximately 300 grams.
In addition to the dietary restrictions discussed above, Dr. Atkins’ weight loss
program recommends regular exercise and nutritional supplementation.
Why do people follow this diet?
The Atkins Diet is attractive to dieters who have tried unsuccessfully to lose weight on low-fat, low-calorie diets. Atkins dieters can
eat as many calories as desired from protein and fat, as long as carbohydrate consumption is
restricted. As a result, many Atkins dieters are spared the feelings of hunger and deprivation
that accompany other weight loss regimens.
What do the advocates say?
The underlying premise of the Atkins Diet is that diets high in carbohydrates cause some
people to gain weight and can ultimately lead to
obesity. Such diets increase the production of insulin (a hormone secreted by the
pancreas). When insulin levels are high, the food we eat is quickly and easily converted into
fat, and stored in our cells. By restricting the consumption of carbohydrates, the production
of insulin is moderated. In addition, the lack of available carbohydrate (the body’s
preferred fuel source) forces the body to burn stored fat as energy.
The changes in metabolism that occur with severe carbohydrate restriction also cause the
body to excrete ketones (breakdown product of fat metabolism) in the urine. Since ketones
contain calories, the loss of ketones in the urine may enhance weight loss.
Until his death in 2003, Dr. Atkins and his colleagues at The Atkins Center for
Complementary Medicine in New York have used this diet to treat patients with obesity, as well
as non-insulin dependent (type 2) diabetes
mellitus (NIDDM), high cholesterol and triglycerides, and elevated blood pressure. His colleagues continue to
treat patients at the Atkins Center for Complementary Medicine in New York using this diet.
Although there has been little scientific research investigating the diet, several supportive
studies were published around the time of Dr. Atkins’ death.
What do the critics say?
Many nutrition experts disagree with the basic premise of the Atkins Diet—the notion
that high-carbohydrate, low-fat diets cause obesity. For evidence of the implausibility of the
Atkins Diet, some nutritionists point out that the traditional Japanese diet is very high in
carbohydrates, low in protein, and very low in fat; however, before the introduction of
high-fat and high-protein Western foods, being overweight was rare in Japan. Such findings
make sense because ounce for ounce, carbohydrates contain far fewer calories than do fats.
These critics blame eating too many calories (from any source) and lack of physical activity
as the primary causes of obesity.
Critics also express concern about the impact of the Atkins Diet on the overall health of
the dieter. Depending on the foods chosen by the dieter, the diet may contain a large amount
of saturated fat and cholesterol, putting those at risk for heart disease in danger. Recent research has found
that high-protein diets speed up the progression of hardening of the arteries (atherosclerosis), the main cause of heart attacks. Moreover, contrary to
Atkins’ claims, extremely low-fat diets have been found to partially reverse
heart disease. In addition, the lack of
grains, fruits, and vegetables in the Atkins Diet may lead to deficiencies
of key nutrients, including dietary fiber, vitamin C, folic acid, and several minerals. Finally, high
protein diets may increase the risk of
osteoporosis and accelerate the rate of deterioration in kidney function associated with
Critics concede that Atkins dieters often experience significant weight loss during the
initial stages of the diet. However, these critics argue that the diet has a diuretic effect
and that the initial weight loss is due to water loss, not fat loss. Eventually the body
restores its water and sodium balance, and the rate of weight loss declines. Critics also note
that there is no evidence showing that the Atkins diet leads to greater weight loss than do
other diets that provide more carbohydrates, yet the same number of calories.
Studies published between 2002 and 2006 tend to support the short-term effectiveness of the
Atkins diet, although not unquestionably. When compared with people who eat a low-fat diet,
Atkins dieters can lose more weight in the first 6 months, but by 12 months there is no
difference in the amount of total weight lost. In addition, while the Atkins diet does not
appear to cause some of the adverse effects about which critics are concerned, there is
evidence that the diet might cause bone loss, and other concerns about long-term safety still
In a six-month study of overweight adults, many of whom had diabetes, those following the
Atkins diet lost an average of 12.8 pounds, compared with only 4.2 pounds for those consuming
a low-fat diet. Similar results were seen in a study of non-diabetic overweight adults,
although the advantage of the Atkins diet over the low-fat diet diminished after six months.
In a study of overweight adolescents, the average weight loss after 12 weeks was 21.8 pounds
in the children consuming the Atkins diet, compared with 9 pounds in those consuming a low-fat
diet. The greater weight loss occurred even though the Atkins group consumed 67% more calories
per day than did the low-fat group.
With regard to safety factors, there were no adverse effects on cholesterol and
triglyceride levels. On the contrary, in one study the Atkins diet was more effective than the
low-fat diet for improving triglyceride levels. Other laboratory tests, however, suggested
that long-term use of the Atkins diet could increase the risk of kidney stones and
osteoporosis. Furthermore, one study found a 2.2% reduction in bone density after only six
weeks on the diet.
Are there any groups or books associated with this diet?
Dr. Atkins’ books on the Atkins Diet include
Dr. Atkins’ New Diet Revolution. Thorndike, ME: G.K.
Dr. Atkins’ Age-Defying Diet Revolution. New York: St.
Martin’s Press, 2000.
Dr. Atkins’ New Diet Cookbook. New York: M. Evans and
Dr. Atkins’ New Carbohydrate Gram Counter: More than 1200
Brand-name and Generic Foods Listed with Carbohydrate, Protein, and Fat Contents. New
York: M. Evans and Company, 1996.
Dr. Atkins’ Vita-Nutrient Solution: Nature’s Answer
To Drugs. New York: Simon & Schuster, 1999.
Official Web site for the Atkins Diet
The American Dietetics Association Web site provides information on
Atkins, RC. Dr. Atkins’ New Diet Revolution (revised and
updated). New York: Avon Books, 1999.
Bravata DM, Sanders L, Huang J, et al. Efficacy and safety of
low-carbohydrate diets: a systematic review. JAMA 2003;289:1837-50 [review].
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comparing a very low carbohydrate diet and a calorie-restricted low fat diet on body weight
and cardiovascular risk factors in healthy women. J Clin Endocrinol Metab
Fleming RM, Boyd LB. The effect of high-protein diets on coronary
blood flow. Angiology 2000;51:817–26.
Foster GD, Wyatt HR, Hill JO, et al. A randomized trial of a
low-carbohydrate diet for obesity. N Engl J Med 2003 22;348:2082–90.
Gould KL, Ornish D, Scherwitz L, et al. Changes in myocardial
perfusion abnormalities by positron emission tomography after long-term, intense risk factor
modification. JAMA 1995;274:894–901.
Nordmann AJ, Nordmann A, Briel M,et al. Effects of low-carbohydrate vs
low-fat diets on weight loss and cardiovascular risk factors: a meta-analysis of randomized
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Raykowski LK. Popular diets: what practitioners should know. Nurse
Reddy ST, Wang CY, Sakhaee K, et al. Effect of low-carbohydrate
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Samaha FF, Iqbal N, Seshadri P, et al. A low-carbohydrate as compared
with a low-fat diet in severe obesity. N Engl J Med 2003;348:2074–81.
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Stein, Karen. High-protein, low-carbohydrate diets: Do they work?
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Volek JS. Personal communication. (Source of the figure of 2.2% bone
Volek JS, Sharman MJ, Gomez AL, et al. An isoenergetic very low
carbohydrate diet improves serum HDL cholesterol and triacylglycerol concentrations, the total
cholesterol to HDL cholesterol ratio and postprandial pipemic responses compared with a low
fat diet in normal weight, normolipidemic women. J Nutr 2003;133:2756–61.
Volek JS, Sharman MJ, Love DM, et al. Body composition and hormonal
responses to a carbohydrate-restricted diet. Metabolism 2002;51:864–70.
The information presented in the Food Guide is for informational purposes
only and was created by a team of US–registered dietitians and food experts. Consult
your doctor, practitioner, and/or pharmacist for any health problem and before using any
supplements, making dietary changes, or before making any changes in prescribed medications.