Chicory, and more specifically a vegetable called Belgian endive, is very similar to cabbage and lettuce. Even though, dr Dukan, did not specifically pointed out this veggie as a valid Attack Phase or Cruise Phase (PP) food, I think it is safe to eat chicory throughout every stage of the Dukan Diet.

Belgian endive contains virtually nothing but some protein and dietary fiber. Moreover, thanks to its refined, somewhat bitter taste, it is an excellent product to add to a meaty and protein rich menu of the Dukan Diet. Chicory can be eaten raw or cooked.

Chicory / Belgian Endive (raw) Nutrition Data →

Chicory is rich in dietary fiber and it is a good source of Vitamins A & C.

It contains no sugar or fat, but unlike lettuce it has much more thicker texture and distinctive taste. So, when having chicory, you actually can feel that you eat some real food :).