This is an eating plan, or a lifestyle change, not a diet. Keep that in perspective and it will help in the long run.
I normally can see results within 3 weeks of being strict on eating, training, and supplementation. That being said, Rome wasnt built in a day, and these are usually subtle changes. Also Ive been doing this for a while and Im in tune with my body, and know where and what to expect.
Bottom line, everyone is different, and we all respond differently, but by the 3 week mark it should become habit, and you should see some subtle results. After 12 weeks you can totally transform your physique.