From the Doc himself. DANDR new paperback edition, page 129.

Special Category Foods
To add variety each day you can also eat 10-20 olives, half a small avocado, one ounce of sour cream or three ounces of unsweetened heavy cream as well as 2-3 tablespoons of lemon or lime juice. But be aware that these foods accasionally slow down weight loss in some people, and may need to be avoided the first two weeks. If you seem to be losing slowly, moderate your intake of these foods.

I would like to add that the above mentioned dairy products should be one of the first things to be crossed off your list if you are experiencing stalls. Along with low-carb bars!