The percentage of carb/fat/protein can be a source of ideology and controversy, but it is probably less important than eating
quality foods in each category (and getting enough protein).
Daily protein recommendation in grams per pound of body weight ranges from 0.4 (for sedentary or light activity) to 1.0 (for heavy strength training; elite levels may go even higher for some periods of time). Someone trying to lose fat and including the recommended amounts of cardio and strength training may want to choose the middle to high end of the range.
Protein Requirements for Athletes Protein Sports Nutrition: Fuel Movement & Sport
Of course, even the high end of the protein recommendations won't be enough daily calories even if you are restricting calories for fat loss. The rest of your calories likely comes from carbohydrates and/or fat. Whatever ratio of these you choose, favor the good types like:
Carbohydrates from vegetables, whole fruits, beans, and whole grains
Fats from fish (types low in contamination with mercury and other pollutants) and vegetable sources other than coconut oil, palm oil, or any hydrogenated oil
and avoid bad types like:
Any hydrogenated oil
Added sugars or foods that are mostly sugar[1]
Refined grain products[2]
Fats from beef, dairy products, coconut oil, or palm oil
Foods that are both high carbohydrate and high fat
[1] Sugar can be found under various names, including corn syrup, cane juice, fructose, etc.
[2] "Wheat flour" and "enriched wheat flour" are refined wheat without the bran; look for "whole wheat".
