If you're eating 160g of protein per day you won't lose muscle as you have enough protein to avoid catabolism. As you're not hungry and getting enough protein, it seems you are starting to burn your reserves. This is how primal is supposed to work. Your progress may not be linear. Don't worry. Stick with it unless things go wrong for you (shouldn't happen)
Four years Primal with influences from Jaminet & Shanahan and a focus on being anti-inflammatory. Using Primal to treat CVD and prevent stents from blocking free of drugs.
Eat creatures nose-to-tail (animal, fowl, fish, crustacea, molluscs), a large variety of vegetables (raw, cooked and fermented, including safe starches), dairy (cheese & yoghurt), occasional fruit, cocoa, turmeric & red wine