I am considering buying some grass-fed elk or deer, but I understand that the nutrient ratio is likely to be 90/10 (protein/fat), or thereabouts. I need more fat in my diet. How do I go about calculating the nutrient ratio if I were to add some elk/deer marrow to ground elk/deer meat? For instance, if I wanted to eat 1.5 lbs of 90/10 meat but end up getting 70% of my calories from fat, how would I figure out how much marrow I need to add to my meal of 1.5lbs. of 90/10 ground meat?
If I have 1 lb. meat, that's 454g. About 69% is water and ash. So 90% by weight is protein and 10% is fat, or 0.31*(454-45.4)g is protein and 0.31*45.4g is fat. In terms of calories, this would come to 0.31*(4cal/g)*(454-45.4)g + 0.31*(9cal/g)*45.4g = 505cal + 127cal. So %cal from fat and protein are 505cal/(505cal + 127cal) and 127cal/(505cal + 127cal) or 80% protein and 20% fat. This is too high in protein and low in fat for me. I would like to get about 70% of calories from fat.
So if F is calories from fat and P is calories from protein, and PCF is percent of calories from fat, then
For two foods (i.e. one marrow, the other ground beef), PCF=(F1+F2)/(F1+F2+P1+P2), where F1,P1 are fat and protein calories in the first food, F2,P2 the second food.
If we use the following data:
Game meat, elk, rawhttp://nutritiondata.self.com/facts/lamb-veal-and-game-products/4635/2
Caribou, bone marrow, rawhttp://nutritiondata.self.com/facts/ethnic-foods/8088/2
Then for 70% calories from fat and with 100g of ground elk (F1,P1):
but P2=(1-0.967)F2=0.033F2 so
So, if caribou marrow has a macronutrient content similar to elk marrow, and the ground elk I receive is about 12% calories from fat, then for each 100g of ground elk I need to add 26g of elk marrow to achieve 70% calories from fat. Is this correct?