I have heard about a low carbohydrate diet. Which foods do not contain carbohydrates?

Germany

Almost all natural foods contain carbohydrates. The only food group which is free of carbohydrates is fats and oils. Even milk products contain carbohydrates, in the form of a sugar called lactose. Fish and meat have very low carbohydrates content. Cereal, pulses, potatoes, fruit and vegetables contain starch and/or sugars, which are carbohydrates.

Read about carbohydrate diet

Is the Atkins or South-beach diet healthy?
http://www.foodexperts.net/nutrition-health/index.php?action=showqa&id=235

Basic facts about carbohydrates
http://www.eufic.org/en/quickfacts/carbohydrates.htm

Food Today Article: „The Highs and Lows of carbohydrates”
http://www.eufic.org/gb/food/pag/food35/food353.htm