A pound of human body fat contains fewer than 3500 calories, given that it contains some protein and fluid weight. To transform dietary intake into body fat is an inherently inefficient process. There is energy loss. So is it likely that it might require a total of 3500 calories in energy to complete the process? Sure.
A pound of lean muscle mass (as round roast) contains 660 calories. Let's say you eat that as a 1 pound steak in addition to your normal equilibrium diet, having put in the killer exercise your body needs to stimulate muscle gain. You have already given your body the building blocks it needs to create a pound of muscle mass. All that is needed is the energy input to transform it from raw materials to muscle. 2840 calories of energy would be necessary? Likely not.
I have heard that a 1:4 ratio O-3:O-6 is adequate and that the total quantity of O-6 is probably more important than the exact ratio you achieve.
Female, 5'3", 48, Starting weight: 163lbs. Current weight: 135.
Starting squat: 45lbs. Current squat: 145 x 4.