What is a Low-Carbohydrate Diet?

Low-carbohydrate diets, such as the Atkins™ diet, the Zone, the Paleo diet, and the South Beach Diet®, have enjoyed a resurgence in popularity. A low-carbohydrate diet limits the amount and types of carbohydrates that may be eaten. Carbohydrates are found in milk products, beans and lentils, seeds, grains, fruits and vegetables, and any other food containing starch or sugar. Carbohydrates are not found in meat, fish, eggs, and fats.

Many people choose to eat a low-carbohydrate diet for health reasons. Carbohydrates cause blood sugar to rise, which in turn elevates insulin levels. This effect is especially pronounced with simple carbohydrates, such as sugar and white flour. Every low-carbohydrate diet excludes or severely limits any food containing sugar or refined starches.

High blood sugar and high insulin levels are associated with a wide number of health problems, including weight gain, high blood pressure, and heart disease. High insulin is also associated with insulin resistance, which can lead to type 2 diabetes. A low-carbohydrate diet is also suitable for persons who are managing diabetes or have another insulin-related disorder, such as metabolic syndrome. Persons who have failed to lose weight on low fat diets or a diet high in carbohydrates may find more success with a low-carb diet.

The best known low-carbohydrate diet is the Atkins™ diet. This diet limits carbohydrate consumption to as little as 20 grams per day initially in order to induce a state of ketosis. In this state, the body burns its stored fat for fuel. Carbohydrate intake is then gradually increased until the dieter reaches a level upon which he can comfortably maintain his weight loss. This final intake will be roughly in the range of 50 to 90 grams per day; by contrast, many experts recommend a minimum of 130 grams of carbohydrates per day.

The South Beach Diet® limits the types of carbohydrates eaten by their position on the glycemic index. The glycemic index is a measure of a food's effect on blood sugar levels; the lower the food is on the index, the less blood sugar is increased. Dieters are encouraged to consume moderate quantities of low glycemic carbohydrates such as beans, whole grains, non-starchy vegetables, and certain whole, fresh fruits. The South Beach Diet® also discourages consumption of foods such as high fat cheese or high fat meats, which are allowed on the Atkins™ diet. This diet can also be adjusted for vegetarians much more easily than the Atkins™ diet.