Background

Carbohydrates are the most common source of energy in the American diet, and they occupy the bottom of the FDA food pyramid. Bran, cereal, bread, potatoes, and pasta all contain high amounts of carbohydrates. A low carbohydrate diet is one in which daily consumption of carbohydrates is limited or reduced, and fats and protein consumption is increased. There are several types of low carbohydrate diets, but the most widely used low carbohydrate diet is the one advocated by Dr. Robert Atkins. The Atkins diet proposes that, in order to lose weight, one should adopt an eating style significantly different from the Food and Drug Administration's (FDA) food pyramid. It proposes the elimination of most carbohydrates as a source of energy and instead to increase the consumption of fats, including trans fats and hydrogenated oils. Another low carbohydrate diet is the South Beach diet.

The Atkins diet can be confused with South Beach diet since they both have the initial two weeks of restricting carbohydrates. However, after this initial phase, the diets become different. Under the South Beach diet, "good" carbohydrates are reintroduced while the Atkins diet does not recommend any carbohydrate consumption.

People use this for...

Safety Safety definitions

Pregnancy And Lactation: There is insufficient reliable evidence about the safety of the low carbohydrate diet in pregnancy and lactation. Avoid following this diet.

Effectiveness Effectiveness definitions

There is insufficient reliable evidence about the safety of the low carbohydrate diet. For effectiveness information about specific low carbohydrate diets such as the Atkins diet and the South Beach diet, see the specific monographs.

Natural Medicines rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.

Dosing & administration

Adverse effects

General: If the elimination of carbohydrates from the diet is complete or drastic, ketosis may occur. Ketosis presents with symptoms of bad breath, tiredness, weakness, dizziness, insomnia and nausea.

Interactions with pharmaceuticals

None known.

Interactions with herbs & supplements

None known.

Interactions with foods

None known.

Interactions with lab tests

Interactions with diseases

Mechanism of action

Eating carbohydrates results in the body's secretion of insulin. Insulin is a substance produced in the body to regulate the metabolism of carbohydrates. Some advocates of the low carbohydrate diet state that increased levels of insulin in the blood result in increased metabolic disorders such as obesity. Therefore, a low carbohydrate diet is followed to promote decreased levels of insulin and weight loss. By reducing carbohydrate intake and increasing protein and fat intake the body will, in theory, lose weight by using stored body fat more efficiently.

The human body derives energy from the carbohydrates, proteins, and fats in food. If the elimination of carbohydrates from the diet is too drastic, the body will start using energy from other sources such as muscle and fat, which, in time, may result in a state of ketosis.