Therefore, each day between 350 and 700 kcal above the daily energy needs would be needed to provide the necessary calories for an increase of 450 to 900 g of lean tissue per week and to meet the energy needs of a training program force.

First you must find out how many calories you need approximately for maintenance.

What's the best way to approach this? I think finding out my baseline would be the most difficult task since it varies depending on how busy work is during the week.

Then, my activity level also varies depending on what I am doing with family during the week I don't work.