This is true. You should limit protein intake to 20 grams in 2hr period to avoid glyconeogenesis, which is the process your body uses to convert protein into glucose. This plus reducing net carbs to 20g or less per day should put you into nutritional ketosis within a week or two. Going keto makes fasting a lot easier. I typically fast between 8pm and noon and find it much much harder when I slip out of keto. If you keep up the program and lift weights (find a good strength program at a gym) your body composition will improve. I managed to get to 8% body fat this way.