Low carbohydrate diets are a matter of controversy for more than hundred years. From time to time this kind of diets are highly popular. In between also opponents are seeing this therapeutic option not only negative. Low-carb-diets are associated with the name of Atkins and his treatment method with an unlimited supply of fat and protein combined with the extreme reduction of carbohydrates. Initially only 20 g of carbohydrates are recommended. Although energy supply is unlimited, obese people will lose weight. – If one main nutrient (carbohydrates or fat) is eliminated in the daily diet, a caloric restriction of 600-800 kcal/day results. Supporter of low-carb-diets don`t see this as the only cause for the weight reduction. – In own comparative studies with energetically limited, isoenergetically diets the weight reduction was higher with low- carb – compared with the high carb diets. Newer studies confirmed these results.