Low-carbohydrate diet Low-carbohydrate diets are nutritional programs that advocate restricted carbohydrate consumption and are limited or replaced with foods containing a higher percentage of proteins, fats, and/or fiber. The Zone Diet, the Protein Power Lifeplan, and the South Beach Diet are all examples of Low-carbohydrate diets.

The key scientific principle which forms the basis for these diets is the relationship between consumption of carbohydrates and their effects on blood sugar (i.e. blood glucose) and hormone production.

This means sharply reducing consumption of desserts, breads, pastas, potatoes, rice, and other sweet or starchy foods.

All Low-carbohydrate diets agree that processed sugar should be eliminated, or at the very least greatly reduced, and similarly generally discourage heavily processed grains (white bread, etc.).

The lowered intake of dietary fiber that often accompanies dramatically reduced carbohydrate intake can result in constipation and increased consumption of animal-based products may lead to high consumption of saturated fat and cholesterol