depends how insane you are about it really. if were talking a reduced 1500 calorie stictly all ground  meat with no condiments or sauce or sides, the person has a resting bmr of 2600, is 6'4 measured large frame, does weights twice a day, drinks nothing but water, isn't allowed to sit at all during their 10 hour a day job which also involves lifting and moving heavy items numerous times a day...