Its normal to reach a plateau for a while when you are losing weight, and its normally changing up your exercise routine or what you eat - in terms of the types of food, calories could be the same) that can get things going again.

If you drop you food intake too much, your body goes into self preservation and can actually start to increase you weight as it tired to hold on to its fat stores as it thinks you are starving.

I would keep it at 1000 or above.