I actually felt it after just a couple weeks. I used to eat about 30% fat and vegan, mostly raw. Now I'm on RawTil4 at 10% or less fat, eating very little cooked food (even for dinner).
But, I was at a restaurant and ordered a cooked vegetable and rice dish that I thought would be low fat from the description, and after I finished it, I immediately started to feel tired and lethargic. I later learned the dish was made with oil and contained about 20g fat. Next time I think I might check the menu/nutrition facts beforehand...
The next day I drank several pounds worth of oranges and started feeling better and better as the day went on. Just forgive yourself and move on. If you pop 1 tire on your car, you go and fix it...you don't go and pop the other 3 :)
i've gotten them to do hygienic dishes