My suggestion...to retain mass....low carb or keto. Low carb Id go 50% Protein/35% Fat/15% Carbs. Im on a pretty similar split and have maintained strength while down about 30 lbs now (13 weeks). Personally I like to get the parameters down (a diet idea and the macros) and once those are in place, you can label read and keep track using things like the Diet Tracker here. It keeps the diet from getting bland.